Revised fragmentation logic

pull key diff into helper
tests: add test_sharding_compaction
2026-07-08 22:50:37 +00:00 · 2024-04-25 18:15:26 +01:00 · 2024-04-25 18:05:59 +01:00 · 2024-04-25 18:05:59 +01:00 · 2024-04-25 18:05:59 +01:00 · 2024-04-25 18:04:23 +01:00
194 changed files with 3314 additions and 9487 deletions
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -478,7 +478,6 @@ jobs:
          PAGESERVER_VIRTUAL_FILE_IO_ENGINE: tokio-epoll-uring
          PAGESERVER_GET_VECTORED_IMPL: vectored
          PAGESERVER_GET_IMPL: vectored
-          PAGESERVER_VALIDATE_VEC_GET: true

      # Temporary disable this step until we figure out why it's so flaky
      # Ref https://github.com/neondatabase/neon/issues/4540
@@ -558,9 +557,6 @@ jobs:
          PERF_TEST_RESULT_CONNSTR: "${{ secrets.PERF_TEST_RESULT_CONNSTR }}"
          TEST_RESULT_CONNSTR: "${{ secrets.REGRESS_TEST_RESULT_CONNSTR_NEW }}"
          PAGESERVER_VIRTUAL_FILE_IO_ENGINE: tokio-epoll-uring
-          PAGESERVER_GET_VECTORED_IMPL: vectored
-          PAGESERVER_GET_IMPL: vectored
-          PAGESERVER_VALIDATE_VEC_GET: false
      # XXX: no coverage data handling here, since benchmarks are run on release builds,
      # while coverage is currently collected for the debug ones

--- a/Cargo.lock
+++ b/Cargo.lock
@@ -213,9 +213,9 @@ dependencies = [

 [[package]]
 name = "async-lock"
-version = "3.3.0"
+version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d034b430882f8381900d3fe6f0aaa3ad94f2cb4ac519b429692a1bc2dda4ae7b"
+checksum = "7125e42787d53db9dd54261812ef17e937c95a51e4d291373b670342fa44310c"
 dependencies = [
 "event-listener 4.0.0",
 "event-listener-strategy",
@@ -595,7 +595,7 @@ dependencies = [
 "http 0.2.9",
 "http-body 0.4.5",
 "hyper 0.14.26",
- "hyper-rustls 0.24.0",
+ "hyper-rustls",
 "once_cell",
 "pin-project-lite",
 "pin-utils",
@@ -684,7 +684,7 @@ dependencies = [
 "http-body 0.4.5",
 "hyper 0.14.26",
 "itoa",
- "matchit 0.7.0",
+ "matchit",
 "memchr",
 "mime",
 "percent-encoding",
@@ -722,9 +722,9 @@ dependencies = [

 [[package]]
 name = "azure_core"
-version = "0.19.0"
+version = "0.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70fd680c0d0424a518229b1150922f92653ba2ac933aa000abc8bf1ca08105f7"
+checksum = "a6218987c374650fdad0b476bfc675729762c28dfb35f58608a38a2b1ea337dd"
 dependencies = [
 "async-trait",
 "base64 0.21.1",
@@ -740,7 +740,7 @@ dependencies = [
 "pin-project",
 "quick-xml",
 "rand 0.8.5",
- "reqwest 0.11.19",
+ "reqwest",
 "rustc_version",
 "serde",
 "serde_json",
@@ -752,9 +752,9 @@ dependencies = [

 [[package]]
 name = "azure_identity"
-version = "0.19.0"
+version = "0.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6d2060f5b2e1c664026ca4edd561306c473be887c1f7a81f10bf06f9b71c63f"
+checksum = "9e1eacc4f7fb2a73d57c39139d0fc3aed78435606055779ddaef4b43cdf919a8"
 dependencies = [
 "async-lock",
 "async-trait",
@@ -772,9 +772,9 @@ dependencies = [

 [[package]]
 name = "azure_storage"
-version = "0.19.0"
+version = "0.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15d3da73bfa09350e1bd6ae2a260806fcf90048c7e78cd2d8f88be60b19a7266"
+checksum = "ade8f2653e408de88b9eafec9f48c3c26b94026375e88adbd34523a7dd9795a1"
 dependencies = [
 "RustyXML",
 "async-lock",
@@ -791,9 +791,9 @@ dependencies = [

 [[package]]
 name = "azure_storage_blobs"
-version = "0.19.0"
+version = "0.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "149c21834a4105d761e3dd33d91c2a3064acc05a3c978848ea8089102ae45c94"
+checksum = "025701c7cc5b523100f0f3b2b01723564ec5a86c03236521c06826337047e872"
 dependencies = [
 "RustyXML",
 "azure_core",
@@ -812,9 +812,9 @@ dependencies = [

 [[package]]
 name = "azure_svc_blobstorage"
-version = "0.19.0"
+version = "0.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88c888b7bf522d5405218b8613bf0fae7ddaae6ef3bf4ad42ae005993c96ab8b"
+checksum = "76051e5bb67cea1055abe5e530a0878feac7e0ab4cbbcb4a6adc953a58993389"
 dependencies = [
 "azure_core",
 "bytes",
@@ -865,12 +865,6 @@ version = "0.21.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f1e31e207a6b8fb791a38ea3105e6cb541f55e4d029902d3039a4ad07cc4105"

-[[package]]
-name = "base64"
-version = "0.22.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
-
 [[package]]
 name = "base64-simd"
 version = "0.8.0"
@@ -1216,7 +1210,7 @@ dependencies = [
 "postgres",
 "regex",
 "remote_storage",
- "reqwest 0.12.4",
+ "reqwest",
 "rust-ini",
 "serde",
 "serde_json",
@@ -1239,9 +1233,9 @@ dependencies = [

 [[package]]
 name = "concurrent-queue"
-version = "2.5.0"
+version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ca0197aee26d1ae37445ee532fefce43251d24cc7c166799f4d46817f1d3973"
+checksum = "f057a694a54f12365049b0958a1685bb52d567f5593b355fbf685838e873d400"
 dependencies = [
 "crossbeam-utils",
 ]
@@ -1325,7 +1319,6 @@ dependencies = [
 "git-version",
 "hex",
 "humantime",
- "humantime-serde",
 "hyper 0.14.26",
 "nix 0.27.1",
 "once_cell",
@@ -1335,7 +1328,7 @@ dependencies = [
 "postgres_backend",
 "postgres_connection",
 "regex",
- "reqwest 0.12.4",
+ "reqwest",
 "safekeeper_api",
 "scopeguard",
 "serde",
@@ -1875,17 +1868,6 @@ dependencies = [
 "pin-project-lite",
 ]

-[[package]]
-name = "event-listener"
-version = "5.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d9944b8ca13534cdfb2800775f8dd4902ff3fc75a50101466decadfdf322a24"
-dependencies = [
- "concurrent-queue",
- "parking",
- "pin-project-lite",
-]
-
 [[package]]
 name = "event-listener-strategy"
 version = "0.4.0"
@@ -2380,17 +2362,6 @@ dependencies = [
 "winapi",
 ]

-[[package]]
-name = "hostname"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9c7c7c8ac16c798734b8a24560c1362120597c40d5e1459f09498f8f6c8f2ba"
-dependencies = [
- "cfg-if",
- "libc",
- "windows 0.52.0",
-]
-
 [[package]]
 name = "http"
 version = "0.2.9"
@@ -2537,7 +2508,6 @@ dependencies = [
 "pin-project-lite",
 "smallvec",
 "tokio",
- "want",
 ]

 [[package]]
@@ -2555,23 +2525,6 @@ dependencies = [
 "tokio-rustls 0.24.0",
 ]

-[[package]]
-name = "hyper-rustls"
-version = "0.26.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0bea761b46ae2b24eb4aef630d8d1c398157b6fc29e6350ecf090a0b70c952c"
-dependencies = [
- "futures-util",
- "http 1.1.0",
- "hyper 1.2.0",
- "hyper-util",
- "rustls 0.22.4",
- "rustls-pki-types",
- "tokio",
- "tokio-rustls 0.25.0",
- "tower-service",
-]
-
 [[package]]
 name = "hyper-timeout"
 version = "0.4.1"
@@ -2619,7 +2572,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ca38ef113da30126bbff9cd1705f9273e15d45498615d138b0c20279ac7a76aa"
 dependencies = [
 "bytes",
- "futures-channel",
 "futures-util",
 "http 1.1.0",
 "http-body 1.0.0",
@@ -2627,9 +2579,6 @@ dependencies = [
 "pin-project-lite",
 "socket2 0.5.5",
 "tokio",
- "tower",
- "tower-service",
- "tracing",
 ]

 [[package]]
@@ -2643,7 +2592,7 @@ dependencies = [
 "iana-time-zone-haiku",
 "js-sys",
 "wasm-bindgen",
- "windows 0.48.0",
+ "windows",
 ]

 [[package]]
@@ -2814,9 +2763,9 @@ dependencies = [

 [[package]]
 name = "js-sys"
-version = "0.3.69"
+version = "0.3.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29c15563dc2726973df627357ce0c9ddddbea194836909d655df6a75d2cf296d"
+checksum = "2f37a4a5928311ac501dee68b3c7613a1037d0edb30c8e5427bd832d55d1b790"
 dependencies = [
 "wasm-bindgen",
 ]
@@ -2966,12 +2915,6 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b87248edafb776e59e6ee64a79086f65890d3510f2c656c000bf2a7e8a0aea40"

-[[package]]
-name = "matchit"
-version = "0.8.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "540f1c43aed89909c0cc0cc604e3bb2f7e7a341a3728a9e6cfe760e733cd11ed"
-
 [[package]]
 name = "md-5"
 version = "0.10.5"
@@ -3105,6 +3048,16 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"

+[[package]]
+name = "mime_guess"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4192263c238a5f0d0c6bfd21f336a313a4ce1c450542449ca191bb657b4642ef"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -3132,30 +3085,6 @@ dependencies = [
 "windows-sys 0.48.0",
 ]

-[[package]]
-name = "moka"
-version = "0.12.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e0d88686dc561d743b40de8269b26eaf0dc58781bde087b0984646602021d08"
-dependencies = [
- "async-lock",
- "async-trait",
- "crossbeam-channel",
- "crossbeam-epoch",
- "crossbeam-utils",
- "event-listener 5.3.0",
- "futures-util",
- "once_cell",
- "parking_lot 0.12.1",
- "quanta",
- "rustc_version",
- "smallvec",
- "tagptr",
- "thiserror",
- "triomphe",
- "uuid",
-]
-
 [[package]]
 name = "multimap"
 version = "0.8.3"
@@ -3255,16 +3184,6 @@ dependencies = [
 "winapi",
 ]

-[[package]]
-name = "nu-ansi-term"
-version = "0.46.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77a8165726e8236064dbb45459242600304b42a5ea24ee2948e18e023bf7ba84"
-dependencies = [
- "overload",
- "winapi",
-]
-
 [[package]]
 name = "num"
 version = "0.4.1"
@@ -3472,7 +3391,7 @@ dependencies = [
 "bytes",
 "http 0.2.9",
 "opentelemetry_api",
- "reqwest 0.11.19",
+ "reqwest",
 ]

 [[package]]
@@ -3490,7 +3409,7 @@ dependencies = [
 "opentelemetry_api",
 "opentelemetry_sdk",
 "prost",
- "reqwest 0.11.19",
+ "reqwest",
 "thiserror",
 "tokio",
 "tonic",
@@ -3601,12 +3520,6 @@ version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4030760ffd992bef45b0ae3f10ce1aba99e33464c90d14dd7c039884963ddc7a"

-[[package]]
-name = "overload"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
-
 [[package]]
 name = "p256"
 version = "0.11.1"
@@ -3719,7 +3632,7 @@ dependencies = [
 "rand 0.8.5",
 "regex",
 "remote_storage",
- "reqwest 0.12.4",
+ "reqwest",
 "rpds",
 "scopeguard",
 "serde",
@@ -3789,7 +3702,7 @@ dependencies = [
 "futures",
 "pageserver_api",
 "postgres",
- "reqwest 0.12.4",
+ "reqwest",
 "serde",
 "thiserror",
 "tokio",
@@ -4398,7 +4311,7 @@ dependencies = [
 "hashlink",
 "hex",
 "hmac",
- "hostname 0.3.1",
+ "hostname",
 "http 1.1.0",
 "http-body-util",
 "humantime",
@@ -4412,7 +4325,6 @@ dependencies = [
 "md5",
 "measured",
 "metrics",
- "moka",
 "native-tls",
 "once_cell",
 "opentelemetry",
@@ -4432,7 +4344,7 @@ dependencies = [
 "redis",
 "regex",
 "remote_storage",
- "reqwest 0.12.4",
+ "reqwest",
 "reqwest-middleware",
 "reqwest-retry",
 "reqwest-tracing",
@@ -4459,7 +4371,6 @@ dependencies = [
 "tokio-postgres-rustls",
 "tokio-rustls 0.25.0",
 "tokio-util",
- "tower-service",
 "tracing",
 "tracing-opentelemetry",
 "tracing-subscriber",
@@ -4474,21 +4385,6 @@ dependencies = [
 "x509-parser",
 ]

-[[package]]
-name = "quanta"
-version = "0.12.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e5167a477619228a0b284fac2674e3c388cba90631d7b7de620e6f1fcd08da5"
-dependencies = [
- "crossbeam-utils",
- "libc",
- "once_cell",
- "raw-cpuid",
- "wasi 0.11.0+wasi-snapshot-preview1",
- "web-sys",
- "winapi",
-]
-
 [[package]]
 name = "quick-xml"
 version = "0.31.0"
@@ -4600,15 +4496,6 @@ dependencies = [
 "rand_core 0.5.1",
 ]

-[[package]]
-name = "raw-cpuid"
-version = "11.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e29830cbb1290e404f24c73af91c5d8d631ce7e128691e9477556b540cd01ecd"
-dependencies = [
- "bitflags 2.4.1",
-]
-
 [[package]]
 name = "rayon"
 version = "1.7.0"
@@ -4774,7 +4661,6 @@ dependencies = [
 "scopeguard",
 "serde",
 "serde_json",
- "sync_wrapper",
 "test-context",
 "tokio",
 "tokio-stream",
@@ -4800,106 +4686,69 @@ dependencies = [
 "http 0.2.9",
 "http-body 0.4.5",
 "hyper 0.14.26",
+ "hyper-rustls",
 "hyper-tls",
 "ipnet",
 "js-sys",
 "log",
 "mime",
+ "mime_guess",
 "native-tls",
 "once_cell",
 "percent-encoding",
 "pin-project-lite",
+ "rustls 0.21.11",
+ "rustls-pemfile 1.0.2",
 "serde",
 "serde_json",
 "serde_urlencoded",
 "tokio",
 "tokio-native-tls",
+ "tokio-rustls 0.24.0",
 "tokio-util",
 "tower-service",
 "url",
 "wasm-bindgen",
 "wasm-bindgen-futures",
- "wasm-streams 0.3.0",
+ "wasm-streams",
 "web-sys",
- "winreg 0.50.0",
-]
-
-[[package]]
-name = "reqwest"
-version = "0.12.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "566cafdd92868e0939d3fb961bd0dc25fcfaaed179291093b3d43e6b3150ea10"
-dependencies = [
- "base64 0.22.1",
- "bytes",
- "futures-channel",
- "futures-core",
- "futures-util",
- "http 1.1.0",
- "http-body 1.0.0",
- "http-body-util",
- "hyper 1.2.0",
- "hyper-rustls 0.26.0",
- "hyper-util",
- "ipnet",
- "js-sys",
- "log",
- "mime",
- "once_cell",
- "percent-encoding",
- "pin-project-lite",
- "rustls 0.22.4",
- "rustls-pemfile 2.1.1",
- "rustls-pki-types",
- "serde",
- "serde_json",
- "serde_urlencoded",
- "sync_wrapper",
- "tokio",
- "tokio-rustls 0.25.0",
- "tokio-util",
- "tower-service",
- "url",
- "wasm-bindgen",
- "wasm-bindgen-futures",
- "wasm-streams 0.4.0",
- "web-sys",
- "webpki-roots 0.26.1",
- "winreg 0.52.0",
+ "webpki-roots 0.25.2",
+ "winreg",
 ]

 [[package]]
 name = "reqwest-middleware"
-version = "0.3.0"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0209efb52486ad88136190094ee214759ef7507068b27992256ed6610eb71a01"
+checksum = "4531c89d50effe1fac90d095c8b133c20c5c714204feee0bfc3fd158e784209d"
 dependencies = [
 "anyhow",
 "async-trait",
- "http 1.1.0",
- "reqwest 0.12.4",
+ "http 0.2.9",
+ "reqwest",
 "serde",
+ "task-local-extensions",
 "thiserror",
- "tower-service",
 ]

 [[package]]
 name = "reqwest-retry"
-version = "0.5.0"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40f342894422862af74c50e1e9601cf0931accc9c6981e5eb413c46603b616b5"
+checksum = "48d0fd6ef4c6d23790399fe15efc8d12cd9f3d4133958f9bd7801ee5cbaec6c4"
 dependencies = [
 "anyhow",
 "async-trait",
 "chrono",
 "futures",
 "getrandom 0.2.11",
- "http 1.1.0",
- "hyper 1.2.0",
+ "http 0.2.9",
+ "hyper 0.14.26",
 "parking_lot 0.11.2",
- "reqwest 0.12.4",
+ "reqwest",
 "reqwest-middleware",
 "retry-policies",
+ "task-local-extensions",
 "tokio",
 "tracing",
 "wasm-timer",
@@ -4907,27 +4756,27 @@ dependencies = [

 [[package]]
 name = "reqwest-tracing"
-version = "0.5.0"
+version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b253954a1979e02eabccd7e9c3d61d8f86576108baa160775e7f160bb4e800a3"
+checksum = "5a0152176687dd5cfe7f507ac1cb1a491c679cfe483afd133a7db7aaea818bb3"
 dependencies = [
 "anyhow",
 "async-trait",
 "getrandom 0.2.11",
- "http 1.1.0",
- "matchit 0.8.2",
+ "matchit",
 "opentelemetry",
- "reqwest 0.12.4",
+ "reqwest",
 "reqwest-middleware",
+ "task-local-extensions",
 "tracing",
 "tracing-opentelemetry",
 ]

 [[package]]
 name = "retry-policies"
-version = "0.3.0"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "493b4243e32d6eedd29f9a398896e35c6943a123b55eec97dcaee98310d25810"
+checksum = "e09bbcb5003282bcb688f0bae741b278e9c7e8f378f561522c9806c58e075d9b"
 dependencies = [
 "anyhow",
 "chrono",
@@ -5236,7 +5085,6 @@ dependencies = [
 "aws-smithy-async",
 "bincode",
 "bytes",
- "camino",
 "chrono",
 "clap",
 "crc32c",
@@ -5246,23 +5094,18 @@ dependencies = [
 "hex",
 "histogram",
 "itertools",
- "native-tls",
 "pageserver",
 "pageserver_api",
- "postgres-native-tls",
- "postgres_ffi",
 "rand 0.8.5",
 "remote_storage",
- "reqwest 0.12.4",
+ "reqwest",
 "serde",
 "serde_json",
 "serde_with",
 "thiserror",
 "tokio",
- "tokio-postgres",
 "tokio-rustls 0.25.0",
 "tokio-stream",
- "tokio-util",
 "tracing",
 "tracing-appender",
 "tracing-subscriber",
@@ -5304,7 +5147,7 @@ dependencies = [
 "rand 0.8.5",
 "regex",
 "remote_storage",
- "reqwest 0.12.4",
+ "reqwest",
 "safekeeper_api",
 "scopeguard",
 "sd-notify",
@@ -5434,12 +5277,12 @@ checksum = "bebd363326d05ec3e2f532ab7660680f3b02130d780c299bca73469d521bc0ed"

 [[package]]
 name = "sentry"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "00421ed8fa0c995f07cde48ba6c89e80f2b312f74ff637326f392fbfd23abe02"
+checksum = "2e95efd0cefa32028cdb9766c96de71d96671072f9fb494dc9fb84c0ef93e52b"
 dependencies = [
 "httpdate",
- "reqwest 0.12.4",
+ "reqwest",
 "rustls 0.21.11",
 "sentry-backtrace",
 "sentry-contexts",
@@ -5453,9 +5296,9 @@ dependencies = [

 [[package]]
 name = "sentry-backtrace"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a79194074f34b0cbe5dd33896e5928bbc6ab63a889bd9df2264af5acb186921e"
+checksum = "6ac2bac6f310c4c4c4bb094d1541d32ae497f8c5c23405e85492cefdfe0971a9"
 dependencies = [
 "backtrace",
 "once_cell",
@@ -5465,11 +5308,11 @@ dependencies = [

 [[package]]
 name = "sentry-contexts"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eba8870c5dba2bfd9db25c75574a11429f6b95957b0a78ac02e2970dd7a5249a"
+checksum = "6c3e17295cecdbacf66c5bd38d6e1147e09e1e9d824d2d5341f76638eda02a3a"
 dependencies = [
- "hostname 0.4.0",
+ "hostname",
 "libc",
 "os_info",
 "rustc_version",
@@ -5479,9 +5322,9 @@ dependencies = [

 [[package]]
 name = "sentry-core"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46a75011ea1c0d5c46e9e57df03ce81f5c7f0a9e199086334a1f9c0a541e0826"
+checksum = "8339474f587f36cb110fa1ed1b64229eea6d47b0b886375579297b7e47aeb055"
 dependencies = [
 "once_cell",
 "rand 0.8.5",
@@ -5492,9 +5335,9 @@ dependencies = [

 [[package]]
 name = "sentry-panic"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2eaa3ecfa3c8750c78dcfd4637cfa2598b95b52897ed184b4dc77fcf7d95060d"
+checksum = "875b69f506da75bd664029eafb05f8934297d2990192896d17325f066bd665b7"
 dependencies = [
 "sentry-backtrace",
 "sentry-core",
@@ -5502,9 +5345,9 @@ dependencies = [

 [[package]]
 name = "sentry-tracing"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f715932bf369a61b7256687c6f0554141b7ce097287e30e3f7ed6e9de82498fe"
+checksum = "89feead9bdd116f8035e89567651340fc382db29240b6c55ef412078b08d1aa3"
 dependencies = [
 "sentry-backtrace",
 "sentry-core",
@@ -5514,13 +5357,13 @@ dependencies = [

 [[package]]
 name = "sentry-types"
-version = "0.32.3"
+version = "0.31.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4519c900ce734f7a0eb7aba0869dfb225a7af8820634a7dd51449e3b093cfb7c"
+checksum = "99dc599bd6646884fc403d593cdcb9816dd67c50cff3271c01ff123617908dcd"
 dependencies = [
 "debugid",
+ "getrandom 0.2.11",
 "hex",
- "rand 0.8.5",
 "serde",
 "serde_json",
 "thiserror",
@@ -5912,12 +5755,10 @@ dependencies = [
 "pageserver_client",
 "postgres_connection",
 "r2d2",
- "reqwest 0.12.4",
+ "reqwest",
 "routerify",
 "serde",
 "serde_json",
- "strum",
- "strum_macros",
 "thiserror",
 "tokio",
 "tokio-util",
@@ -5936,7 +5777,7 @@ dependencies = [
 "hyper 0.14.26",
 "pageserver_api",
 "pageserver_client",
- "reqwest 0.12.4",
+ "reqwest",
 "serde",
 "serde_json",
 "thiserror",
@@ -5990,7 +5831,7 @@ checksum = "81cdd64d312baedb58e21336b31bc043b77e01cc99033ce76ef539f78e965ebc"
 [[package]]
 name = "svg_fmt"
 version = "0.4.2"
-source = "git+https://github.com/neondatabase/fork--nical--rust_debug?branch=neon#c1820b28664b5df68de7f043fccf2ed5d67b6ae8"
+source = "git+https://github.com/neondatabase/fork--nical--rust_debug?branch=neon#b9501105e746629004bc6d0473639320939dbe10"

 [[package]]
 name = "syn"
@@ -6019,9 +5860,6 @@ name = "sync_wrapper"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
-dependencies = [
- "futures-core",
-]

 [[package]]
 name = "synstructure"
@@ -6050,12 +5888,6 @@ dependencies = [
 "winapi",
 ]

-[[package]]
-name = "tagptr"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b2093cf4c8eb1e67749a6762251bc9cd836b6fc171623bd0a9d324d37af2417"
-
 [[package]]
 name = "tar"
 version = "0.4.40"
@@ -6646,14 +6478,12 @@ dependencies = [

 [[package]]
 name = "tracing-opentelemetry"
-version = "0.21.0"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75327c6b667828ddc28f5e3f169036cb793c3f588d83bf0f262a7f062ffed3c8"
+checksum = "fc09e402904a5261e42cf27aea09ccb7d5318c6717a9eec3d8e2e65c56b18f19"
 dependencies = [
 "once_cell",
 "opentelemetry",
- "opentelemetry_sdk",
- "smallvec",
 "tracing",
 "tracing-core",
 "tracing-log",
@@ -6677,7 +6507,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "30a651bc37f915e81f087d86e62a18eec5f79550c7faff886f7090b4ea757c77"
 dependencies = [
 "matchers",
- "nu-ansi-term",
 "once_cell",
 "regex",
 "serde",
@@ -6699,7 +6528,7 @@ dependencies = [
 "opentelemetry",
 "opentelemetry-otlp",
 "opentelemetry-semantic-conventions",
- "reqwest 0.12.4",
+ "reqwest",
 "tokio",
 "tracing",
 "tracing-opentelemetry",
@@ -6707,12 +6536,6 @@ dependencies = [
 "workspace_hack",
 ]

-[[package]]
-name = "triomphe"
-version = "0.1.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "859eb650cfee7434994602c3a68b25d77ad9e68c8a6cd491616ef86661382eb3"
-
 [[package]]
 name = "try-lock"
 version = "0.2.4"
@@ -6791,6 +6614,15 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "unicase"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50f37be617794602aabbeee0be4f259dc1778fabe05e2d67ee8f79326d5cb4f6"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.13"
@@ -7072,9 +6904,9 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"

 [[package]]
 name = "wasm-bindgen"
-version = "0.2.92"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4be2531df63900aeb2bca0daaaddec08491ee64ceecbee5076636a3b026795a8"
+checksum = "5bba0e8cb82ba49ff4e229459ff22a191bbe9a1cb3a341610c9c33efc27ddf73"
 dependencies = [
 "cfg-if",
 "wasm-bindgen-macro",
@@ -7082,9 +6914,9 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.92"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "614d787b966d3989fa7bb98a654e369c762374fd3213d212cfc0251257e747da"
+checksum = "19b04bc93f9d6bdee709f6bd2118f57dd6679cf1176a1af464fca3ab0d66d8fb"
 dependencies = [
 "bumpalo",
 "log",
@@ -7097,9 +6929,9 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.42"
+version = "0.4.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76bc14366121efc8dbb487ab05bcc9d346b3b5ec0eaa76e46594cabbe51762c0"
+checksum = "2d1985d03709c53167ce907ff394f5316aa22cb4e12761295c5dc57dacb6297e"
 dependencies = [
 "cfg-if",
 "js-sys",
@@ -7109,9 +6941,9 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.92"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1f8823de937b71b9460c0c34e25f3da88250760bec0ebac694b49997550d726"
+checksum = "14d6b024f1a526bb0234f52840389927257beb670610081360e5a03c5df9c258"
 dependencies = [
 "quote",
 "wasm-bindgen-macro-support",
@@ -7119,9 +6951,9 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.92"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
+checksum = "e128beba882dd1eb6200e1dc92ae6c5dbaa4311aa7bb211ca035779e5efc39f8"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -7132,9 +6964,9 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.92"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af190c94f2773fdb3729c55b007a722abb5384da03bc0986df4c289bf5567e96"
+checksum = "ed9d5b4305409d1fc9482fee2d7f9bcbf24b3972bf59817ef757e23982242a93"

 [[package]]
 name = "wasm-streams"
@@ -7149,19 +6981,6 @@ dependencies = [
 "web-sys",
 ]

-[[package]]
-name = "wasm-streams"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b65dc4c90b63b118468cf747d8bf3566c1913ef60be765b5730ead9e0a3ba129"
-dependencies = [
- "futures-util",
- "js-sys",
- "wasm-bindgen",
- "wasm-bindgen-futures",
- "web-sys",
-]
-
 [[package]]
 name = "wasm-timer"
 version = "0.2.5"
@@ -7179,9 +6998,9 @@ dependencies = [

 [[package]]
 name = "web-sys"
-version = "0.3.69"
+version = "0.3.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77afa9a11836342370f4817622a2f0f418b134426d91a82dfb48f532d2ec13ef"
+checksum = "3bdd9ef4e984da1187bf8110c5cf5b845fbc87a23602cdf912386a76fcd3a7c2"
 dependencies = [
 "js-sys",
 "wasm-bindgen",
@@ -7202,15 +7021,6 @@ version = "0.25.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14247bb57be4f377dfb94c72830b8ce8fc6beac03cf4bf7b9732eadd414123fc"

-[[package]]
-name = "webpki-roots"
-version = "0.26.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b3de34ae270483955a94f4b21bdaaeb83d508bb84a01435f393818edb0012009"
-dependencies = [
- "rustls-pki-types",
-]
-
 [[package]]
 name = "which"
 version = "4.4.0"
@@ -7262,25 +7072,6 @@ dependencies = [
 "windows-targets 0.48.0",
 ]

-[[package]]
-name = "windows"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e48a53791691ab099e5e2ad123536d0fff50652600abaf43bbf952894110d0be"
-dependencies = [
- "windows-core",
- "windows-targets 0.52.4",
-]
-
-[[package]]
-name = "windows-core"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33ab640c8d7e35bf8ba19b884ba838ceb4fba93a4e8c65a9059d08afcfc683d9"
-dependencies = [
- "windows-targets 0.52.4",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.42.0"
@@ -7513,16 +7304,6 @@ dependencies = [
 "windows-sys 0.48.0",
 ]

-[[package]]
-name = "winreg"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a277a57398d4bfa075df44f501a17cfdf8542d224f0d36095a2adc7aee4ef0a5"
-dependencies = [
- "cfg-if",
- "windows-sys 0.48.0",
-]
-
 [[package]]
 name = "workspace_hack"
 version = "0.1.0"
@@ -7542,7 +7323,6 @@ dependencies = [
 "chrono",
 "clap",
 "clap_builder",
- "crossbeam-epoch",
 "crossbeam-utils",
 "either",
 "fail",
@@ -7573,8 +7353,7 @@ dependencies = [
 "regex",
 "regex-automata 0.4.3",
 "regex-syntax 0.8.2",
- "reqwest 0.11.19",
- "reqwest 0.12.4",
+ "reqwest",
 "rustls 0.21.11",
 "scopeguard",
 "serde",
@@ -7584,7 +7363,6 @@ dependencies = [
 "subtle",
 "syn 1.0.109",
 "syn 2.0.52",
- "sync_wrapper",
 "time",
 "time-macros",
 "tokio",
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -45,10 +45,10 @@ anyhow = { version = "1.0", features = ["backtrace"] }
 arc-swap = "1.6"
 async-compression = { version = "0.4.0", features = ["tokio", "gzip", "zstd"] }
 atomic-take = "1.1.0"
-azure_core = "0.19"
-azure_identity = "0.19"
-azure_storage = "0.19"
-azure_storage_blobs = "0.19"
+azure_core = "0.18"
+azure_identity = "0.18"
+azure_storage = "0.18"
+azure_storage_blobs = "0.18"
 flate2 = "1.0.26"
 async-stream = "0.3"
 async-trait = "0.1"
@@ -130,10 +130,10 @@ prost = "0.11"
 rand = "0.8"
 redis = { version = "0.25.2", features = ["tokio-rustls-comp", "keep-alive"] }
 regex = "1.10.2"
-reqwest = { version = "0.12", default-features = false, features = ["rustls-tls"] }
-reqwest-tracing = { version = "0.5", features = ["opentelemetry_0_20"] }
-reqwest-middleware = "0.3.0"
-reqwest-retry = "0.5"
+reqwest = { version = "0.11", default-features = false, features = ["rustls-tls"] }
+reqwest-tracing = { version = "0.4.7", features = ["opentelemetry_0_20"] }
+reqwest-middleware = "0.2.0"
+reqwest-retry = "0.2.2"
 routerify = "3"
 rpds = "0.13"
 rustc-hash = "1.1.0"
@@ -143,7 +143,7 @@ rustls-split = "0.3"
 scopeguard = "1.1"
 sysinfo = "0.29.2"
 sd-notify = "0.4.1"
-sentry = { version = "0.32", default-features = false, features = ["backtrace", "contexts", "panic", "rustls", "reqwest" ] }
+sentry = { version = "0.31", default-features = false, features = ["backtrace", "contexts", "panic", "rustls", "reqwest" ] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
 serde_path_to_error = "0.1"
@@ -177,11 +177,10 @@ tokio-util = { version = "0.7.10", features = ["io", "rt"] }
 toml = "0.7"
 toml_edit = "0.19"
 tonic = {version = "0.9", features = ["tls", "tls-roots"]}
-tower-service = "0.3.2"
 tracing = "0.1"
 tracing-error = "0.2.0"
-tracing-opentelemetry = "0.21.0"
-tracing-subscriber = { version = "0.3", default_features = false, features = ["smallvec", "fmt", "tracing-log", "std", "env-filter", "json", "ansi"] }
+tracing-opentelemetry = "0.20.0"
+tracing-subscriber = { version = "0.3", default_features = false, features = ["smallvec", "fmt", "tracing-log", "std", "env-filter", "json"] }
 twox-hash = { version = "1.6.3", default-features = false }
 url = "2.2"
 urlencoding = "2.1"
--- a/Dockerfile.build-tools
+++ b/Dockerfile.build-tools
@@ -65,7 +65,7 @@ RUN curl -sL "https://github.com/peak/s5cmd/releases/download/v${S5CMD_VERSION}/
    && mv s5cmd /usr/local/bin/s5cmd

 # LLVM
-ENV LLVM_VERSION=18
+ENV LLVM_VERSION=17
 RUN curl -fsSL 'https://apt.llvm.org/llvm-snapshot.gpg.key' | apt-key add - \
    && echo "deb http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye-${LLVM_VERSION} main" > /etc/apt/sources.list.d/llvm.stable.list \
    && apt update \
@@ -141,7 +141,7 @@ WORKDIR /home/nonroot

 # Rust
 # Please keep the version of llvm (installed above) in sync with rust llvm (`rustc --version --verbose | grep LLVM`)
-ENV RUSTC_VERSION=1.78.0
+ENV RUSTC_VERSION=1.77.0
 ENV RUSTUP_HOME="/home/nonroot/.rustup"
 ENV PATH="/home/nonroot/.cargo/bin:${PATH}"
 RUN curl -sSO https://static.rust-lang.org/rustup/dist/$(uname -m)-unknown-linux-gnu/rustup-init && whoami && \
--- a/18
+++ b/18
@@ -25,16 +25,14 @@ ifeq ($(UNAME_S),Linux)
 	# Seccomp BPF is only available for Linux
 	PG_CONFIGURE_OPTS += --with-libseccomp
 else ifeq ($(UNAME_S),Darwin)
-	ifndef DISABLE_HOMEBREW
-		# macOS with brew-installed openssl requires explicit paths
-		# It can be configured with OPENSSL_PREFIX variable
-		OPENSSL_PREFIX ?= $(shell brew --prefix openssl@3)
-		PG_CONFIGURE_OPTS += --with-includes=$(OPENSSL_PREFIX)/include --with-libraries=$(OPENSSL_PREFIX)/lib
-		PG_CONFIGURE_OPTS += PKG_CONFIG_PATH=$(shell brew --prefix icu4c)/lib/pkgconfig
-		# macOS already has bison and flex in the system, but they are old and result in postgres-v14 target failure
-		# brew formulae are keg-only and not symlinked into HOMEBREW_PREFIX, force their usage
-		EXTRA_PATH_OVERRIDES += $(shell brew --prefix bison)/bin/:$(shell brew --prefix flex)/bin/:
-	endif
+	# macOS with brew-installed openssl requires explicit paths
+	# It can be configured with OPENSSL_PREFIX variable
+	OPENSSL_PREFIX ?= $(shell brew --prefix openssl@3)
+	PG_CONFIGURE_OPTS += --with-includes=$(OPENSSL_PREFIX)/include --with-libraries=$(OPENSSL_PREFIX)/lib
+	PG_CONFIGURE_OPTS += PKG_CONFIG_PATH=$(shell brew --prefix icu4c)/lib/pkgconfig
+	# macOS already has bison and flex in the system, but they are old and result in postgres-v14 target failure
+	# brew formulae are keg-only and not symlinked into HOMEBREW_PREFIX, force their usage
+	EXTRA_PATH_OVERRIDES += $(shell brew --prefix bison)/bin/:$(shell brew --prefix flex)/bin/:
 endif

 # Use -C option so that when PostgreSQL "make install" installs the
--- a/compute_tools/src/bin/compute_ctl.rs
+++ b/compute_tools/src/bin/compute_ctl.rs
@@ -47,7 +47,7 @@ use chrono::Utc;
 use clap::Arg;
 use signal_hook::consts::{SIGQUIT, SIGTERM};
 use signal_hook::{consts::SIGINT, iterator::Signals};
-use tracing::{error, info, warn};
+use tracing::{error, info};
 use url::Url;

 use compute_api::responses::ComputeStatus;
@@ -62,7 +62,6 @@ use compute_tools::logger::*;
 use compute_tools::monitor::launch_monitor;
 use compute_tools::params::*;
 use compute_tools::spec::*;
-use compute_tools::swap::resize_swap;

 // this is an arbitrary build tag. Fine as a default / for testing purposes
 // in-case of not-set environment var
@@ -111,7 +110,6 @@ fn main() -> Result<()> {
        .expect("Postgres connection string is required");
    let spec_json = matches.get_one::<String>("spec");
    let spec_path = matches.get_one::<String>("spec-path");
-    let resize_swap_on_bind = matches.get_flag("resize-swap-on-bind");

    // Extract OpenTelemetry context for the startup actions from the
    // TRACEPARENT and TRACESTATE env variables, and attach it to the current
@@ -228,14 +226,14 @@ fn main() -> Result<()> {

    // If this is a pooled VM, prewarm before starting HTTP server and becoming
    // available for binding. Prewarming helps Postgres start quicker later,
-    // because QEMU will already have its memory allocated from the host, and
+    // because QEMU will already have it's memory allocated from the host, and
    // the necessary binaries will already be cached.
    if !spec_set {
        compute.prewarm_postgres()?;
    }

-    // Launch http service first, so that we can serve control-plane requests
-    // while configuration is still in progress.
+    // Launch http service first, so we were able to serve control-plane
+    // requests, while configuration is still in progress.
    let _http_handle =
        launch_http_server(http_port, &compute).expect("cannot launch http endpoint thread");

@@ -255,22 +253,21 @@ fn main() -> Result<()> {
                break;
            }
        }
-
-        // Record for how long we slept waiting for the spec.
-        let now = Utc::now();
-        state.metrics.wait_for_spec_ms = now
-            .signed_duration_since(state.start_time)
-            .to_std()
-            .unwrap()
-            .as_millis() as u64;
-
-        // Reset start time, so that the total startup time that is calculated later will
-        // not include the time that we waited for the spec.
-        state.start_time = now;
    }

    // We got all we need, update the state.
    let mut state = compute.state.lock().unwrap();
+
+    // Record for how long we slept waiting for the spec.
+    state.metrics.wait_for_spec_ms = Utc::now()
+        .signed_duration_since(state.start_time)
+        .to_std()
+        .unwrap()
+        .as_millis() as u64;
+    // Reset start time to the actual start of the configuration, so that
+    // total startup time was properly measured at the end.
+    state.start_time = Utc::now();
+
    state.status = ComputeStatus::Init;
    compute.state_changed.notify_all();

@@ -278,72 +275,33 @@ fn main() -> Result<()> {
        "running compute with features: {:?}",
        state.pspec.as_ref().unwrap().spec.features
    );
-    // before we release the mutex, fetch the swap size (if any) for later.
-    let swap_size_bytes = state.pspec.as_ref().unwrap().spec.swap_size_bytes;
    drop(state);

    // Launch remaining service threads
    let _monitor_handle = launch_monitor(&compute);
    let _configurator_handle = launch_configurator(&compute);

-    let mut prestartup_failed = false;
-    let mut delay_exit = false;
-
-    // Resize swap to the desired size if the compute spec says so
-    if let (Some(size_bytes), true) = (swap_size_bytes, resize_swap_on_bind) {
-        // To avoid 'swapoff' hitting postgres startup, we need to run resize-swap to completion
-        // *before* starting postgres.
-        //
-        // In theory, we could do this asynchronously if SkipSwapon was enabled for VMs, but this
-        // carries a risk of introducing hard-to-debug issues - e.g. if postgres sometimes gets
-        // OOM-killed during startup because swap wasn't available yet.
-        match resize_swap(size_bytes) {
-            Ok(()) => {
-                let size_gib = size_bytes as f32 / (1 << 20) as f32; // just for more coherent display.
-                info!(%size_bytes, %size_gib, "resized swap");
-            }
-            Err(err) => {
-                let err = err.context("failed to resize swap");
-                error!("{err:#}");
-
-                // Mark compute startup as failed; don't try to start postgres, and report this
-                // error to the control plane when it next asks.
-                prestartup_failed = true;
-                let mut state = compute.state.lock().unwrap();
-                state.error = Some(format!("{err:?}"));
-                state.status = ComputeStatus::Failed;
-                compute.state_changed.notify_all();
-                delay_exit = true;
-            }
-        }
-    }
-
    // Start Postgres
-    let mut pg = None;
+    let mut delay_exit = false;
    let mut exit_code = None;
-
-    if !prestartup_failed {
-        pg = match compute.start_compute(extension_server_port) {
-            Ok(pg) => Some(pg),
-            Err(err) => {
-                error!("could not start the compute node: {:#}", err);
-                let mut state = compute.state.lock().unwrap();
-                state.error = Some(format!("{:?}", err));
-                state.status = ComputeStatus::Failed;
-                // Notify others that Postgres failed to start. In case of configuring the
-                // empty compute, it's likely that API handler is still waiting for compute
-                // state change. With this we will notify it that compute is in Failed state,
-                // so control plane will know about it earlier and record proper error instead
-                // of timeout.
-                compute.state_changed.notify_all();
-                drop(state); // unlock
-                delay_exit = true;
-                None
-            }
-        };
-    } else {
-        warn!("skipping postgres startup because pre-startup step failed");
-    }
+    let pg = match compute.start_compute(extension_server_port) {
+        Ok(pg) => Some(pg),
+        Err(err) => {
+            error!("could not start the compute node: {:#}", err);
+            let mut state = compute.state.lock().unwrap();
+            state.error = Some(format!("{:?}", err));
+            state.status = ComputeStatus::Failed;
+            // Notify others that Postgres failed to start. In case of configuring the
+            // empty compute, it's likely that API handler is still waiting for compute
+            // state change. With this we will notify it that compute is in Failed state,
+            // so control plane will know about it earlier and record proper error instead
+            // of timeout.
+            compute.state_changed.notify_all();
+            drop(state); // unlock
+            delay_exit = true;
+            None
+        }
+    };

    // Start the vm-monitor if directed to. The vm-monitor only runs on linux
    // because it requires cgroups.
@@ -568,11 +526,6 @@ fn cli() -> clap::Command {
                )
                .value_name("FILECACHE_CONNSTR"),
        )
-        .arg(
-            Arg::new("resize-swap-on-bind")
-                .long("resize-swap-on-bind")
-                .action(clap::ArgAction::SetTrue),
-        )
 }

 /// When compute_ctl is killed, send also termination signal to sync-safekeepers
--- a/compute_tools/src/lib.rs
+++ b/compute_tools/src/lib.rs
@@ -14,5 +14,4 @@ pub mod monitor;
 pub mod params;
 pub mod pg_helpers;
 pub mod spec;
-pub mod swap;
 pub mod sync_sk;
--- a/compute_tools/src/spec.rs
+++ b/compute_tools/src/spec.rs
@@ -490,7 +490,7 @@ pub fn handle_databases(spec: &ComputeSpec, client: &mut Client) -> Result<()> {
                "rename_db" => {
                    let new_name = op.new_name.as_ref().unwrap();

-                    if existing_dbs.contains_key(&op.name) {
+                    if existing_dbs.get(&op.name).is_some() {
                        let query: String = format!(
                            "ALTER DATABASE {} RENAME TO {}",
                            op.name.pg_quote(),
--- a/compute_tools/src/swap.rs
+++ b/compute_tools/src/swap.rs
@@ -1,36 +0,0 @@
-use anyhow::{anyhow, Context};
-use tracing::warn;
-
-pub const RESIZE_SWAP_BIN: &str = "/neonvm/bin/resize-swap";
-
-pub fn resize_swap(size_bytes: u64) -> anyhow::Result<()> {
-    // run `/neonvm/bin/resize-swap --once {size_bytes}`
-    //
-    // Passing '--once' causes resize-swap to delete itself after successful completion, which
-    // means that if compute_ctl restarts later, we won't end up calling 'swapoff' while
-    // postgres is running.
-    //
-    // NOTE: resize-swap is not very clever. If present, --once MUST be the first arg.
-    let child_result = std::process::Command::new("/usr/bin/sudo")
-        .arg(RESIZE_SWAP_BIN)
-        .arg("--once")
-        .arg(size_bytes.to_string())
-        .spawn();
-
-    if matches!(&child_result, Err(e) if e.kind() == std::io::ErrorKind::NotFound) {
-        warn!("ignoring \"not found\" error from resize-swap to avoid swapoff while compute is running");
-        return Ok(());
-    }
-
-    child_result
-        .context("spawn() failed")
-        .and_then(|mut child| child.wait().context("wait() failed"))
-        .and_then(|status| match status.success() {
-            true => Ok(()),
-            false => Err(anyhow!("process exited with {status}")),
-        })
-        // wrap any prior error with the overall context that we couldn't run the command
-        .with_context(|| {
-            format!("could not run `/usr/bin/sudo {RESIZE_SWAP_BIN} --once {size_bytes}`")
-        })
-}
--- a/control_plane/Cargo.toml
+++ b/control_plane/Cargo.toml
@@ -17,7 +17,6 @@ nix.workspace = true
 once_cell.workspace = true
 postgres.workspace = true
 hex.workspace = true
-humantime-serde.workspace = true
 hyper.workspace = true
 regex.workspace = true
 reqwest = { workspace = true, features = ["blocking", "json"] }
--- a/control_plane/src/bin/neon_local.rs
+++ b/control_plane/src/bin/neon_local.rs
@@ -14,15 +14,15 @@ use control_plane::pageserver::{PageServerNode, PAGESERVER_REMOTE_STORAGE_DIR};
 use control_plane::safekeeper::SafekeeperNode;
 use control_plane::storage_controller::StorageController;
 use control_plane::{broker, local_env};
-use pageserver_api::config::{
-    DEFAULT_HTTP_LISTEN_PORT as DEFAULT_PAGESERVER_HTTP_PORT,
-    DEFAULT_PG_LISTEN_PORT as DEFAULT_PAGESERVER_PG_PORT,
-};
 use pageserver_api::controller_api::PlacementPolicy;
 use pageserver_api::models::{
    ShardParameters, TenantCreateRequest, TimelineCreateRequest, TimelineInfo,
 };
 use pageserver_api::shard::{ShardCount, ShardStripeSize, TenantShardId};
+use pageserver_api::{
+    DEFAULT_HTTP_LISTEN_PORT as DEFAULT_PAGESERVER_HTTP_PORT,
+    DEFAULT_PG_LISTEN_PORT as DEFAULT_PAGESERVER_PG_PORT,
+};
 use postgres_backend::AuthType;
 use postgres_connection::parse_host_port;
 use safekeeper_api::{
@@ -417,54 +417,6 @@ async fn handle_tenant(
                println!("{} {:?}", t.id, t.state);
            }
        }
-        Some(("import", import_match)) => {
-            let tenant_id = parse_tenant_id(import_match)?.unwrap_or_else(TenantId::generate);
-
-            let storage_controller = StorageController::from_env(env);
-            let create_response = storage_controller.tenant_import(tenant_id).await?;
-
-            let shard_zero = create_response
-                .shards
-                .first()
-                .expect("Import response omitted shards");
-
-            let attached_pageserver_id = shard_zero.node_id;
-            let pageserver =
-                PageServerNode::from_env(env, env.get_pageserver_conf(attached_pageserver_id)?);
-
-            println!(
-                "Imported tenant {tenant_id}, attached to pageserver {attached_pageserver_id}"
-            );
-
-            let timelines = pageserver
-                .http_client
-                .list_timelines(shard_zero.shard_id)
-                .await?;
-
-            // Pick a 'main' timeline that has no ancestors, the rest will get arbitrary names
-            let main_timeline = timelines
-                .iter()
-                .find(|t| t.ancestor_timeline_id.is_none())
-                .expect("No timelines found")
-                .timeline_id;
-
-            let mut branch_i = 0;
-            for timeline in timelines.iter() {
-                let branch_name = if timeline.timeline_id == main_timeline {
-                    "main".to_string()
-                } else {
-                    branch_i += 1;
-                    format!("branch_{branch_i}")
-                };
-
-                println!(
-                    "Importing timeline {tenant_id}/{} as branch {branch_name}",
-                    timeline.timeline_id
-                );
-
-                env.register_branch_mapping(branch_name, tenant_id, timeline.timeline_id)?;
-            }
-        }
        Some(("create", create_match)) => {
            let tenant_conf: HashMap<_, _> = create_match
                .get_many::<String>("config")
@@ -837,8 +789,6 @@ async fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Re
                .copied()
                .unwrap_or(false);

-            let allow_multiple = sub_args.get_flag("allow-multiple");
-
            let mode = match (lsn, hot_standby) {
                (Some(lsn), false) => ComputeMode::Static(lsn),
                (None, true) => ComputeMode::Replica,
@@ -856,9 +806,7 @@ async fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Re
                _ => {}
            }

-            if !allow_multiple {
-                cplane.check_conflicting_endpoints(mode, tenant_id, timeline_id)?;
-            }
+            cplane.check_conflicting_endpoints(mode, tenant_id, timeline_id)?;

            cplane.new_endpoint(
                &endpoint_id,
@@ -887,8 +835,6 @@ async fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Re

            let remote_ext_config = sub_args.get_one::<String>("remote-ext-config");

-            let allow_multiple = sub_args.get_flag("allow-multiple");
-
            // If --safekeepers argument is given, use only the listed safekeeper nodes.
            let safekeepers =
                if let Some(safekeepers_str) = sub_args.get_one::<String>("safekeepers") {
@@ -914,13 +860,11 @@ async fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Re
                .cloned()
                .unwrap_or_default();

-            if !allow_multiple {
-                cplane.check_conflicting_endpoints(
-                    endpoint.mode,
-                    endpoint.tenant_id,
-                    endpoint.timeline_id,
-                )?;
-            }
+            cplane.check_conflicting_endpoints(
+                endpoint.mode,
+                endpoint.tenant_id,
+                endpoint.timeline_id,
+            )?;

            let (pageservers, stripe_size) = if let Some(pageserver_id) = pageserver_id {
                let conf = env.get_pageserver_conf(pageserver_id).unwrap();
@@ -1452,12 +1396,6 @@ fn cli() -> Command {
        .help("If set, will create test user `user` and `neondb` database. Requires `update-catalog = true`")
        .required(false);

-    let allow_multiple = Arg::new("allow-multiple")
-        .help("Allow multiple primary endpoints running on the same branch. Shouldn't be used normally, but useful for tests.")
-        .long("allow-multiple")
-        .action(ArgAction::SetTrue)
-        .required(false);
-
    Command::new("Neon CLI")
        .arg_required_else_help(true)
        .version(GIT_VERSION)
@@ -1542,8 +1480,6 @@ fn cli() -> Command {
            .subcommand(Command::new("config")
                .arg(tenant_id_arg.clone())
                .arg(Arg::new("config").short('c').num_args(1).action(ArgAction::Append).required(false)))
-            .subcommand(Command::new("import").arg(tenant_id_arg.clone().required(true))
-                .about("Import a tenant that is present in remote storage, and create branches for its timelines"))
        )
        .subcommand(
            Command::new("pageserver")
@@ -1568,8 +1504,8 @@ fn cli() -> Command {
            Command::new("storage_controller")
                .arg_required_else_help(true)
                .about("Manage storage_controller")
-                .subcommand(Command::new("start").about("Start storage controller"))
-                .subcommand(Command::new("stop").about("Stop storage controller")
+                .subcommand(Command::new("start").about("Start local pageserver").arg(pageserver_config_args.clone()))
+                .subcommand(Command::new("stop").about("Stop local pageserver")
                            .arg(stop_mode_arg.clone()))
        )
        .subcommand(
@@ -1615,7 +1551,6 @@ fn cli() -> Command {
                    .arg(pg_version_arg.clone())
                    .arg(hot_standby_arg.clone())
                    .arg(update_catalog)
-                    .arg(allow_multiple.clone())
                )
                .subcommand(Command::new("start")
                    .about("Start postgres.\n If the endpoint doesn't exist yet, it is created.")
@@ -1624,7 +1559,6 @@ fn cli() -> Command {
                    .arg(safekeepers_arg)
                    .arg(remote_ext_config_args)
                    .arg(create_test_user)
-                    .arg(allow_multiple.clone())
                )
                .subcommand(Command::new("reconfigure")
                            .about("Reconfigure the endpoint")
--- a/control_plane/src/endpoint.rs
+++ b/control_plane/src/endpoint.rs
@@ -554,7 +554,6 @@ impl Endpoint {
            format_version: 1.0,
            operation_uuid: None,
            features: self.features.clone(),
-            swap_size_bytes: None,
            cluster: Cluster {
                cluster_id: None, // project ID: not used
                name: None,       // project name: not used
--- a/control_plane/src/local_env.rs
+++ b/control_plane/src/local_env.rs
@@ -17,7 +17,6 @@ use std::net::Ipv4Addr;
 use std::net::SocketAddr;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
-use std::time::Duration;
 use utils::{
    auth::{encode_from_key_file, Claims},
    id::{NodeId, TenantId, TenantTimelineId, TimelineId},
@@ -67,10 +66,6 @@ pub struct LocalEnv {

    pub broker: NeonBroker,

-    // Configuration for the storage controller (1 per neon_local environment)
-    #[serde(default)]
-    pub storage_controller: NeonStorageControllerConf,
-
    /// This Vec must always contain at least one pageserver
    pub pageservers: Vec<PageServerConf>,

@@ -103,29 +98,6 @@ pub struct NeonBroker {
    pub listen_addr: SocketAddr,
 }

-/// Broker config for cluster internal communication.
-#[derive(Serialize, Deserialize, PartialEq, Eq, Clone, Debug)]
-#[serde(default)]
-pub struct NeonStorageControllerConf {
-    /// Heartbeat timeout before marking a node offline
-    #[serde(with = "humantime_serde")]
-    pub max_unavailable: Duration,
-}
-
-impl NeonStorageControllerConf {
-    // Use a shorter pageserver unavailability interval than the default to speed up tests.
-    const DEFAULT_MAX_UNAVAILABLE_INTERVAL: std::time::Duration =
-        std::time::Duration::from_secs(10);
-}
-
-impl Default for NeonStorageControllerConf {
-    fn default() -> Self {
-        Self {
-            max_unavailable: Self::DEFAULT_MAX_UNAVAILABLE_INTERVAL,
-        }
-    }
-}
-
 // Dummy Default impl to satisfy Deserialize derive.
 impl Default for NeonBroker {
    fn default() -> Self {
@@ -158,7 +130,6 @@ pub struct PageServerConf {
    pub(crate) virtual_file_io_engine: Option<String>,
    pub(crate) get_vectored_impl: Option<String>,
    pub(crate) get_impl: Option<String>,
-    pub(crate) validate_vectored_get: Option<bool>,
 }

 impl Default for PageServerConf {
@@ -172,7 +143,6 @@ impl Default for PageServerConf {
            virtual_file_io_engine: None,
            get_vectored_impl: None,
            get_impl: None,
-            validate_vectored_get: None,
        }
    }
 }
@@ -382,10 +352,7 @@ impl LocalEnv {

        // Find neon binaries.
        if env.neon_distrib_dir == Path::new("") {
-            env::current_exe()?
-                .parent()
-                .unwrap()
-                .clone_into(&mut env.neon_distrib_dir);
+            env.neon_distrib_dir = env::current_exe()?.parent().unwrap().to_owned();
        }

        if env.pageservers.is_empty() {
--- a/control_plane/src/pageserver.rs
+++ b/control_plane/src/pageserver.rs
@@ -4,6 +4,7 @@
 //!
 //!   .neon/
 //!
+use std::borrow::Cow;
 use std::collections::HashMap;

 use std::io;
@@ -92,7 +93,6 @@ impl PageServerNode {
            virtual_file_io_engine,
            get_vectored_impl,
            get_impl,
-            validate_vectored_get,
        } = &self.conf;

        let id = format!("id={}", id);
@@ -117,11 +117,6 @@ impl PageServerNode {
        } else {
            String::new()
        };
-        let validate_vectored_get = if let Some(validate_vectored_get) = validate_vectored_get {
-            format!("validate_vectored_get={validate_vectored_get}")
-        } else {
-            String::new()
-        };

        let broker_endpoint_param = format!("broker_endpoint='{}'", self.env.broker.client_url());

@@ -136,7 +131,6 @@ impl PageServerNode {
            virtual_file_io_engine,
            get_vectored_impl,
            get_impl,
-            validate_vectored_get,
        ];

        if let Some(control_plane_api) = &self.env.control_plane_api {
@@ -197,7 +191,7 @@ impl PageServerNode {
    }

    pub async fn start(&self, config_overrides: &[&str]) -> anyhow::Result<()> {
-        self.start_node(config_overrides).await
+        self.start_node(config_overrides, false).await
    }

    fn pageserver_init(&self, config_overrides: &[&str]) -> anyhow::Result<()> {
@@ -218,18 +212,11 @@ impl PageServerNode {
        let datadir_path_str = datadir.to_str().with_context(|| {
            format!("Cannot start pageserver node {node_id} in path that has no string representation: {datadir:?}")
        })?;
+        let mut args = self.pageserver_basic_args(config_overrides, datadir_path_str);
+        args.push(Cow::Borrowed("--init"));

-        // `pageserver --init` merges the `--config-override`s into a built-in default config,
-        // then writes out the merged product to `pageserver.toml`.
-        // TODO: just write the full `pageserver.toml` and get rid of `--config-override`.
-        let mut args = vec!["--init", "--workdir", datadir_path_str];
-        let overrides = self.neon_local_overrides(config_overrides);
-        for piece in &overrides {
-            args.push("--config-override");
-            args.push(piece);
-        }
        let init_output = Command::new(self.env.pageserver_bin())
-            .args(args)
+            .args(args.iter().map(Cow::as_ref))
            .envs(self.pageserver_env_variables()?)
            .output()
            .with_context(|| format!("Failed to run pageserver init for node {node_id}"))?;
@@ -254,13 +241,12 @@ impl PageServerNode {
        // situation: the metadata is written by some other script.
        std::fs::write(
            metadata_path,
-            serde_json::to_vec(&pageserver_api::config::NodeMetadata {
-                postgres_host: "localhost".to_string(),
-                postgres_port: self.pg_connection_config.port(),
-                http_host: "localhost".to_string(),
-                http_port,
-                other: HashMap::new(),
-            })
+            serde_json::to_vec(&serde_json::json!({
+                "host": "localhost",
+                "port": self.pg_connection_config.port(),
+                "http_host": "localhost",
+                "http_port": http_port,
+            }))
            .unwrap(),
        )
        .expect("Failed to write metadata file");
@@ -268,7 +254,11 @@ impl PageServerNode {
        Ok(())
    }

-    async fn start_node(&self, config_overrides: &[&str]) -> anyhow::Result<()> {
+    async fn start_node(
+        &self,
+        config_overrides: &[&str],
+        update_config: bool,
+    ) -> anyhow::Result<()> {
        // TODO: using a thread here because start_process() is not async but we need to call check_status()
        let datadir = self.repo_path();
        print!(
@@ -285,16 +275,15 @@ impl PageServerNode {
                self.conf.id, datadir,
            )
        })?;
-        let mut args = vec!["-D", datadir_path_str];
-        for config_override in config_overrides {
-            args.push("--config-override");
-            args.push(*config_override);
+        let mut args = self.pageserver_basic_args(config_overrides, datadir_path_str);
+        if update_config {
+            args.push(Cow::Borrowed("--update-config"));
        }
        background_process::start_process(
            "pageserver",
            &datadir,
            &self.env.pageserver_bin(),
-            args,
+            args.iter().map(Cow::as_ref),
            self.pageserver_env_variables()?,
            background_process::InitialPidFile::Expect(self.pid_file()),
            || async {
@@ -311,6 +300,22 @@ impl PageServerNode {
        Ok(())
    }

+    fn pageserver_basic_args<'a>(
+        &self,
+        config_overrides: &'a [&'a str],
+        datadir_path_str: &'a str,
+    ) -> Vec<Cow<'a, str>> {
+        let mut args = vec![Cow::Borrowed("-D"), Cow::Borrowed(datadir_path_str)];
+
+        let overrides = self.neon_local_overrides(config_overrides);
+        for config_override in overrides {
+            args.push(Cow::Borrowed("-c"));
+            args.push(Cow::Owned(config_override));
+        }
+
+        args
+    }
+
    fn pageserver_env_variables(&self) -> anyhow::Result<Vec<(String, String)>> {
        // FIXME: why is this tied to pageserver's auth type? Whether or not the safekeeper
        // needs a token, and how to generate that token, seems independent to whether
@@ -436,11 +441,6 @@ impl PageServerNode {
                .map(serde_json::from_str)
                .transpose()
                .context("parse `timeline_get_throttle` from json")?,
-            switch_to_aux_file_v2: settings
-                .remove("switch_to_aux_file_v2")
-                .map(|x| x.parse::<bool>())
-                .transpose()
-                .context("Failed to parse 'switch_to_aux_file_v2' as bool")?,
        };
        if !settings.is_empty() {
            bail!("Unrecognized tenant settings: {settings:?}")
@@ -559,11 +559,6 @@ impl PageServerNode {
                    .map(serde_json::from_str)
                    .transpose()
                    .context("parse `timeline_get_throttle` from json")?,
-                switch_to_aux_file_v2: settings
-                    .remove("switch_to_aux_file_v2")
-                    .map(|x| x.parse::<bool>())
-                    .transpose()
-                    .context("Failed to parse 'switch_to_aux_file_v2' as bool")?,
            }
        };

--- a/control_plane/src/storage_controller.rs
+++ b/control_plane/src/storage_controller.rs
@@ -1,8 +1,6 @@
-use crate::{
-    background_process,
-    local_env::{LocalEnv, NeonStorageControllerConf},
-};
+use crate::{background_process, local_env::LocalEnv};
 use camino::{Utf8Path, Utf8PathBuf};
+use hyper::Method;
 use pageserver_api::{
    controller_api::{
        NodeConfigureRequest, NodeRegisterRequest, TenantCreateResponse, TenantLocateResponse,
@@ -16,7 +14,6 @@ use pageserver_api::{
 };
 use pageserver_client::mgmt_api::ResponseErrorMessageExt;
 use postgres_backend::AuthType;
-use reqwest::Method;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::{fs, str::FromStr};
 use tokio::process::Command;
@@ -35,13 +32,15 @@ pub struct StorageController {
    public_key: Option<String>,
    postgres_port: u16,
    client: reqwest::Client,
-    config: NeonStorageControllerConf,
 }

 const COMMAND: &str = "storage_controller";

 const STORAGE_CONTROLLER_POSTGRES_VERSION: u32 = 16;

+// Use a shorter pageserver unavailability interval than the default to speed up tests.
+const NEON_LOCAL_MAX_UNAVAILABLE_INTERVAL: std::time::Duration = std::time::Duration::from_secs(10);
+
 #[derive(Serialize, Deserialize)]
 pub struct AttachHookRequest {
    pub tenant_shard_id: TenantShardId,
@@ -136,7 +135,6 @@ impl StorageController {
            client: reqwest::ClientBuilder::new()
                .build()
                .expect("Failed to construct http client"),
-            config: env.storage_controller.clone(),
        }
    }

@@ -274,6 +272,8 @@ impl StorageController {
        // Run migrations on every startup, in case something changed.
        let database_url = self.setup_database().await?;

+        let max_unavailable: humantime::Duration = NEON_LOCAL_MAX_UNAVAILABLE_INTERVAL.into();
+
        let mut args = vec![
            "-l",
            &self.listen,
@@ -283,7 +283,7 @@ impl StorageController {
            "--database-url",
            &database_url,
            "--max-unavailable-interval",
-            &humantime::Duration::from(self.config.max_unavailable).to_string(),
+            &max_unavailable.to_string(),
        ]
        .into_iter()
        .map(|s| s.to_string())
@@ -379,7 +379,7 @@ impl StorageController {
    /// Simple HTTP request wrapper for calling into storage controller
    async fn dispatch<RQ, RS>(
        &self,
-        method: reqwest::Method,
+        method: hyper::Method,
        path: String,
        body: Option<RQ>,
    ) -> anyhow::Result<RS>
@@ -472,16 +472,6 @@ impl StorageController {
            .await
    }

-    #[instrument(skip(self))]
-    pub async fn tenant_import(&self, tenant_id: TenantId) -> anyhow::Result<TenantCreateResponse> {
-        self.dispatch::<(), TenantCreateResponse>(
-            Method::POST,
-            format!("debug/v1/tenant/{tenant_id}/import"),
-            None,
-        )
-        .await
-    }
-
    #[instrument(skip(self))]
    pub async fn tenant_locate(&self, tenant_id: TenantId) -> anyhow::Result<TenantLocateResponse> {
        self.dispatch::<(), _>(
--- a/control_plane/storcon_cli/src/main.rs
+++ b/control_plane/storcon_cli/src/main.rs
@@ -1,6 +1,7 @@
 use std::{collections::HashMap, str::FromStr, time::Duration};

 use clap::{Parser, Subcommand};
+use hyper::{Method, StatusCode};
 use pageserver_api::{
    controller_api::{
        NodeAvailabilityWrapper, NodeDescribeResponse, ShardSchedulingPolicy,
@@ -13,7 +14,7 @@ use pageserver_api::{
    shard::{ShardStripeSize, TenantShardId},
 };
 use pageserver_client::mgmt_api::{self, ResponseErrorMessageExt};
-use reqwest::{Method, StatusCode, Url};
+use reqwest::Url;
 use serde::{de::DeserializeOwned, Serialize};
 use utils::id::{NodeId, TenantId};

@@ -231,7 +232,7 @@ impl Client {
    /// Simple HTTP request wrapper for calling into storage controller
    async fn dispatch<RQ, RS>(
        &self,
-        method: Method,
+        method: hyper::Method,
        path: String,
        body: Option<RQ>,
    ) -> mgmt_api::Result<RS>
--- a/docs/storage_controller.md
+++ b/docs/storage_controller.md
@@ -30,7 +30,7 @@ The storage controller uses a postgres database to persist a subset of its state
 persist the _relationships_ between them: the attachment state of a tenant's shards to nodes is kept in memory and
 rebuilt on startup.

-The file `persistence.rs` contains all the code for accessing the database, and has a large doc comment that goes into more detail about exactly what we persist and why.
+The file `[persistence.rs](http://persistence.rs)` contains all the code for accessing the database, and has a large doc comment that goes into more detail about exactly what we persist and why.

 The `diesel` crate is used for defining models & migrations.

--- a/libs/compute_api/src/spec.rs
+++ b/libs/compute_api/src/spec.rs
@@ -33,23 +33,6 @@ pub struct ComputeSpec {
    #[serde(default)]
    pub features: Vec<ComputeFeature>,

-    /// If compute_ctl was passed `--resize-swap-on-bind`, a value of `Some(_)` instructs
-    /// compute_ctl to `/neonvm/bin/resize-swap` with the given size, when the spec is first
-    /// received.
-    ///
-    /// Both this field and `--resize-swap-on-bind` are required, so that the control plane's
-    /// spec generation doesn't need to be aware of the actual compute it's running on, while
-    /// guaranteeing gradual rollout of swap. Otherwise, without `--resize-swap-on-bind`, we could
-    /// end up trying to resize swap in VMs without it -- or end up *not* resizing swap, thus
-    /// giving every VM much more swap than it should have (32GiB).
-    ///
-    /// Eventually we may remove `--resize-swap-on-bind` and exclusively use `swap_size_bytes` for
-    /// enabling the swap resizing behavior once rollout is complete.
-    ///
-    /// See neondatabase/cloud#12047 for more.
-    #[serde(default)]
-    pub swap_size_bytes: Option<u64>,
-
    /// Expected cluster state at the end of transition process.
    pub cluster: Cluster,
    pub delta_operations: Option<Vec<DeltaOp>>,
--- a/libs/pageserver_api/src/config.rs
+++ b/libs/pageserver_api/src/config.rs
@@ -1,31 +0,0 @@
-use std::collections::HashMap;
-
-use const_format::formatcp;
-
-#[cfg(test)]
-mod tests;
-
-pub const DEFAULT_PG_LISTEN_PORT: u16 = 64000;
-pub const DEFAULT_PG_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_PG_LISTEN_PORT}");
-pub const DEFAULT_HTTP_LISTEN_PORT: u16 = 9898;
-pub const DEFAULT_HTTP_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_HTTP_LISTEN_PORT}");
-
-// Certain metadata (e.g. externally-addressable name, AZ) is delivered
-// as a separate structure.  This information is not neeed by the pageserver
-// itself, it is only used for registering the pageserver with the control
-// plane and/or storage controller.
-//
-#[derive(PartialEq, Eq, Debug, serde::Serialize, serde::Deserialize)]
-pub struct NodeMetadata {
-    #[serde(rename = "host")]
-    pub postgres_host: String,
-    #[serde(rename = "port")]
-    pub postgres_port: u16,
-    pub http_host: String,
-    pub http_port: u16,
-
-    // Deployment tools may write fields to the metadata file beyond what we
-    // use in this type: this type intentionally only names fields that require.
-    #[serde(flatten)]
-    pub other: HashMap<String, serde_json::Value>,
-}
--- a/libs/pageserver_api/src/config/tests.rs
+++ b/libs/pageserver_api/src/config/tests.rs
@@ -1,22 +0,0 @@
-use super::*;
-
-#[test]
-fn test_node_metadata_v1_backward_compatibilty() {
-    let v1 = serde_json::to_vec(&serde_json::json!({
-        "host": "localhost",
-        "port": 23,
-        "http_host": "localhost",
-        "http_port": 42,
-    }));
-
-    assert_eq!(
-        serde_json::from_slice::<NodeMetadata>(&v1.unwrap()).unwrap(),
-        NodeMetadata {
-            postgres_host: "localhost".to_string(),
-            postgres_port: 23,
-            http_host: "localhost".to_string(),
-            http_port: 42,
-            other: HashMap::new(),
-        }
-    )
-}
--- a/libs/pageserver_api/src/key.rs
+++ b/libs/pageserver_api/src/key.rs
@@ -4,6 +4,7 @@ use bytes::BufMut;
 use postgres_ffi::relfile_utils::{FSM_FORKNUM, VISIBILITYMAP_FORKNUM};
 use postgres_ffi::{Oid, TransactionId};
 use serde::{Deserialize, Serialize};
+use std::ops::RangeInclusive;
 use std::{fmt, ops::Range};

 use crate::reltag::{BlockNumber, RelTag, SlruKind};
@@ -29,25 +30,24 @@ pub const KEY_SIZE: usize = 18;
 /// See [`Key::to_i128`] for more information on the encoding.
 pub const METADATA_KEY_SIZE: usize = 16;

-/// The key prefix start range for the metadata keys. All keys with the first byte >= 0x40 is a metadata key.
-pub const METADATA_KEY_BEGIN_PREFIX: u8 = 0x60;
-pub const METADATA_KEY_END_PREFIX: u8 = 0x7F;
+/// The key prefix start range for the metadata keys. All keys with the first byte >= 0x80 is a metadata key.
+pub const METADATA_KEY_BEGIN_PREFIX: u8 = 0x80;

 /// The (reserved) key prefix of relation sizes.
-pub const RELATION_SIZE_PREFIX: u8 = 0x61;
+pub const RELATION_SIZE_PREFIX: u8 = 0x81;

 /// The key prefix of AUX file keys.
-pub const AUX_KEY_PREFIX: u8 = 0x62;
+pub const AUX_KEY_PREFIX: u8 = 0x82;

 /// Check if the key falls in the range of metadata keys.
 pub const fn is_metadata_key_slice(key: &[u8]) -> bool {
-    key[0] >= METADATA_KEY_BEGIN_PREFIX && key[0] < METADATA_KEY_END_PREFIX
+    key[0] >= METADATA_KEY_BEGIN_PREFIX
 }

 impl Key {
    /// Check if the key falls in the range of metadata keys.
    pub const fn is_metadata_key(&self) -> bool {
-        self.field1 >= METADATA_KEY_BEGIN_PREFIX && self.field1 < METADATA_KEY_END_PREFIX
+        self.field1 >= METADATA_KEY_BEGIN_PREFIX
    }

    /// Encode a metadata key to a storage key.
@@ -80,7 +80,7 @@ impl Key {
    }

    /// Get the range of metadata keys.
-    pub const fn metadata_key_range() -> Range<Self> {
+    pub fn metadata_key_range() -> RangeInclusive<Self> {
        Key {
            field1: METADATA_KEY_BEGIN_PREFIX,
            field2: 0,
@@ -88,32 +88,13 @@ impl Key {
            field4: 0,
            field5: 0,
            field6: 0,
-        }..Key {
-            field1: METADATA_KEY_END_PREFIX,
-            field2: 0,
-            field3: 0,
-            field4: 0,
-            field5: 0,
-            field6: 0,
-        }
-    }
-
-    /// Get the range of aux keys.
-    pub fn metadata_aux_key_range() -> Range<Self> {
-        Key {
-            field1: AUX_KEY_PREFIX,
-            field2: 0,
-            field3: 0,
-            field4: 0,
-            field5: 0,
-            field6: 0,
-        }..Key {
-            field1: AUX_KEY_PREFIX + 1,
-            field2: 0,
-            field3: 0,
-            field4: 0,
-            field5: 0,
-            field6: 0,
+        }..=Key {
+            field1: u8::MAX,
+            field2: u16::MAX as u32,
+            field3: u32::MAX,
+            field4: u32::MAX,
+            field5: u8::MAX,
+            field6: u32::MAX,
        }
    }

@@ -122,7 +103,7 @@ impl Key {
    /// we can assume that only some predefined namespace OIDs are used which can fit in u16
    pub fn to_i128(&self) -> i128 {
        assert!(self.field2 < 0xFFFF || self.field2 == 0xFFFFFFFF || self.field2 == 0x22222222);
-        (((self.field1 & 0x7F) as i128) << 120)
+        (((self.field1 & 0xf) as i128) << 120)
            | (((self.field2 & 0xFFFF) as i128) << 104)
            | ((self.field3 as i128) << 72)
            | ((self.field4 as i128) << 40)
@@ -132,7 +113,7 @@ impl Key {

    pub const fn from_i128(x: i128) -> Self {
        Key {
-            field1: ((x >> 120) & 0x7F) as u8,
+            field1: ((x >> 120) & 0xf) as u8,
            field2: ((x >> 104) & 0xFFFF) as u32,
            field3: (x >> 72) as u32,
            field4: (x >> 40) as u32,
@@ -572,17 +553,14 @@ pub const AUX_FILES_KEY: Key = Key {
 // Reverse mappings for a few Keys.
 // These are needed by WAL redo manager.

-/// Non inherited range for vectored get.
 pub const NON_INHERITED_RANGE: Range<Key> = AUX_FILES_KEY..AUX_FILES_KEY.next();
-/// Sparse keyspace range for vectored get. Missing key error will be ignored for this range.
-pub const NON_INHERITED_SPARSE_RANGE: Range<Key> = Key::metadata_key_range();

 // AUX_FILES currently stores only data for logical replication (slots etc), and
 // we don't preserve these on a branch because safekeepers can't follow timeline
 // switch (and generally it likely should be optional), so ignore these.
 #[inline(always)]
 pub fn is_inherited_key(key: Key) -> bool {
-    !NON_INHERITED_RANGE.contains(&key) && !NON_INHERITED_SPARSE_RANGE.contains(&key)
+    !NON_INHERITED_RANGE.contains(&key)
 }

 #[inline(always)]
--- a/libs/pageserver_api/src/keyspace.rs
+++ b/libs/pageserver_api/src/keyspace.rs
@@ -17,10 +17,6 @@ pub struct KeySpace {
    pub ranges: Vec<Range<Key>>,
 }

-/// A wrapper type for sparse keyspaces.
-#[derive(Clone, Debug, Default, PartialEq, Eq)]
-pub struct SparseKeySpace(pub KeySpace);
-
 /// Represents a contiguous half-open range of the keyspace, masked according to a particular
 /// ShardNumber's stripes: within this range of keys, only some "belong" to the current
 /// shard.
@@ -36,34 +32,12 @@ pub struct ShardedRange<'a> {
    pub range: Range<Key>,
 }

-// Calculate the size of a range within the blocks of the same relation, or spanning only the
-// top page in the previous relation's space.
-fn contiguous_range_len(range: &Range<Key>) -> u32 {
-    debug_assert!(is_contiguous_range(range));
-    if range.start.field6 == 0xffffffff {
-        range.end.field6 + 1
-    } else {
-        range.end.field6 - range.start.field6
-    }
-}
-
-/// Return true if this key range includes only keys in the same relation's data blocks, or
-/// just spanning one relation and the logical size (0xffffffff) block of the relation before it.
-///
-/// Contiguous in this context means we know the keys are in use _somewhere_, but it might not
-/// be on our shard.  Later in ShardedRange we do the extra work to figure out how much
-/// of a given contiguous range is present on one shard.
-///
-/// This matters, because:
-/// - Within such ranges, keys are used contiguously.  Outside such ranges it is sparse.
-/// - Within such ranges, we may calculate distances using simple subtraction of field6.
-fn is_contiguous_range(range: &Range<Key>) -> bool {
-    range.start.field1 == range.end.field1
-        && range.start.field2 == range.end.field2
-        && range.start.field3 == range.end.field3
-        && range.start.field4 == range.end.field4
-        && (range.start.field5 == range.end.field5
-            || (range.start.field6 == 0xffffffff && range.start.field5 + 1 == range.end.field5))
+// Calculate the distance between two keys, assuming that they are somewhat close
+// together (i.e. we only account for field5 and field6)
+fn nearby_key_delta(start: &Key, end: &Key) -> u64 {
+    let start = (start.field5 as u64) << 32 | start.field6 as u64;
+    let end = (end.field5 as u64) << 32 | end.field6 as u64;
+    end - start
 }

 impl<'a> ShardedRange<'a> {
@@ -89,7 +63,11 @@ impl<'a> ShardedRange<'a> {
            )];
        }

-        if !is_contiguous_range(&self.range) {
+        if self.range.end.field1 != self.range.start.field1
+            || self.range.end.field2 != self.range.start.field2
+            || self.range.end.field3 != self.range.start.field3
+            || self.range.end.field4 != self.range.start.field4
+        {
            // Ranges that span relations are not fragmented.  We only get these ranges as a result
            // of operations that act on existing layers, so we trust that the existing range is
            // reasonably small.
@@ -100,7 +78,7 @@ impl<'a> ShardedRange<'a> {

        let mut cursor = self.range.start;
        while cursor < self.range.end {
-            let advance_by = self.distance_to_next_boundary(cursor);
+            let advance_by = self.advance_to_next_boundary(cursor);
            let is_fragment_disposable = self.shard_identity.is_key_disposable(&cursor);

            // If the previous fragment is undersized, then we seek to consume enough
@@ -158,23 +136,21 @@ impl<'a> ShardedRange<'a> {
    /// Estimate the physical pages that are within this range, on this shard.  This returns
    /// u32::MAX if the range spans relations: this return value should be interpreted as "large".
    pub fn page_count(&self) -> u32 {
-        // Special cases for single keys like logical sizes
-        if self.range.end == self.range.start.add(1) {
-            return if self.shard_identity.is_key_disposable(&self.range.start) {
-                0
-            } else {
-                1
-            };
-        }
-
-        // We can only do an authentic calculation of contiguous key ranges
-        if !is_contiguous_range(&self.range) {
+        let raw_size = Self::raw_size(&self.range);
+        if raw_size == u32::MAX {
            return u32::MAX;
        }

        // Special case for single sharded tenants: our logical and physical sizes are the same
        if self.shard_identity.count < ShardCount::new(2) {
-            return contiguous_range_len(&self.range);
+            return raw_size;
+        }
+
+        // Special cases for single keys like logical sizes
+        if self.range.end == self.range.start.add(1)
+            && self.shard_identity.is_key_local(&self.range.start)
+        {
+            return 1;
        }

        // Normal path: step through stripes and part-stripes in the range, evaluate whether each one belongs
@@ -183,16 +159,18 @@ impl<'a> ShardedRange<'a> {
        let mut cursor = self.range.start;
        while cursor < self.range.end {
            // Count up to the next stripe_size boundary or end of range
-            let advance_by = self.distance_to_next_boundary(cursor);
+            let advance_by = self.advance_to_next_boundary(cursor);
+            cursor = cursor.add(advance_by);

            // If this blocks in this stripe belong to us, add them to our count
            if !self.shard_identity.is_key_disposable(&cursor) {
                result += advance_by as u64;
            }
-
-            cursor = cursor.add(advance_by);
        }

+        // Sharding should always decrease the number of pages we estimate, never increase it
+        debug_assert!(result <= raw_size as u64);
+
        if result > u32::MAX as u64 {
            u32::MAX
        } else {
@@ -202,37 +180,19 @@ impl<'a> ShardedRange<'a> {

    /// Advance the cursor to the next potential fragment boundary: this is either
    /// a stripe boundary, or the end of the range.
-    fn distance_to_next_boundary(&self, cursor: Key) -> u32 {
-        let distance_to_range_end = contiguous_range_len(&(cursor..self.range.end));
+    fn advance_to_next_boundary(&self, cursor: Key) -> u32 {
+        let distance_to_range_end = nearby_key_delta(&cursor, &self.range.end);

        if self.shard_identity.count < ShardCount::new(2) {
            // Optimization: don't bother stepping through stripes if the tenant isn't sharded.
-            return distance_to_range_end;
-        }
-
-        if cursor.field6 == 0xffffffff {
-            // We are wrapping from one relation's logical size to the next relation's first data block
-            return 1;
+            return Self::raw_size(&self.range);
        }

        let stripe_index = cursor.field6 / self.shard_identity.stripe_size.0;
        let stripe_remainder = self.shard_identity.stripe_size.0
            - (cursor.field6 - stripe_index * self.shard_identity.stripe_size.0);

-        if cfg!(debug_assertions) {
-            // We should never overflow field5 and field6 -- our callers check this earlier
-            // and would have returned their u32::MAX cases if the input range violated this.
-            let next_cursor = cursor.add(stripe_remainder);
-            debug_assert!(
-                next_cursor.field1 == cursor.field1
-                    && next_cursor.field2 == cursor.field2
-                    && next_cursor.field3 == cursor.field3
-                    && next_cursor.field4 == cursor.field4
-                    && next_cursor.field5 == cursor.field5
-            )
-        }
-
-        std::cmp::min(stripe_remainder, distance_to_range_end)
+        std::cmp::min(stripe_remainder as u64, distance_to_range_end) as u32
    }

    /// Whereas `page_count` estimates the number of pages physically in this range on this shard,
@@ -241,22 +201,29 @@ impl<'a> ShardedRange<'a> {
    ///
    /// Don't use this function in code that works with physical entities like layer files.
    fn raw_size(range: &Range<Key>) -> u32 {
-        if is_contiguous_range(range) {
-            contiguous_range_len(range)
-        } else {
+        let start = range.start;
+        let end = range.end;
+
+        if end.field1 != start.field1
+            || end.field2 != start.field2
+            || end.field3 != start.field3
+            || end.field4 != start.field4
+        {
+            return u32::MAX;
+        }
+
+        // The check above ensures that keys only differ in low fields (i.e. are nearby)
+        let diff = nearby_key_delta(&start, &end);
+        if diff > u32::MAX as u64 {
            u32::MAX
+        } else {
+            diff as u32
        }
    }
 }

 impl KeySpace {
-    /// Create a key space with a single range.
-    pub fn single(key_range: Range<Key>) -> Self {
-        Self {
-            ranges: vec![key_range],
-        }
-    }
-
+    ///
    /// Partition a key space into roughly chunks of roughly 'target_size' bytes
    /// in each partition.
    ///
@@ -273,12 +240,12 @@ impl KeySpace {
            let range = ShardedRange::new(range.clone(), shard_identity);

            // Chunk up the range into parts that each contain up to target_size local blocks
-            for (frag_on_shard_size, frag_range) in range.fragment(target_nblocks) {
+            for (range_size, range) in range.fragment(target_nblocks) {
                // If appending the next contiguous range in the keyspace to the current
                // partition would cause it to be too large, and our current partition
                // covers at least one block that is physically present in this shard,
                // then start a new partition
-                if current_part_size + frag_on_shard_size as usize > target_nblocks as usize
+                if current_part_size + range_size as usize > target_nblocks as usize
                    && current_part_size > 0
                {
                    parts.push(KeySpace {
@@ -287,8 +254,8 @@ impl KeySpace {
                    current_part = Vec::new();
                    current_part_size = 0;
                }
-                current_part.push(frag_range.start..frag_range.end);
-                current_part_size += frag_on_shard_size as usize;
+                current_part.push(range.start..range.end);
+                current_part_size += range_size as usize;
            }
        }

@@ -302,10 +269,6 @@ impl KeySpace {
        KeyPartitioning { parts }
    }

-    pub fn is_empty(&self) -> bool {
-        self.total_raw_size() == 0
-    }
-
    /// Merge another keyspace into the current one.
    /// Note: the keyspaces must not ovelap (enforced via assertions)
    pub fn merge(&mut self, other: &KeySpace) {
@@ -404,6 +367,10 @@ impl KeySpace {
            .sum()
    }

+    pub fn is_empty(&self) -> bool {
+        self.total_raw_size() == 0
+    }
+
    fn overlaps_at(&self, range: &Range<Key>) -> Option<usize> {
        match self.ranges.binary_search_by_key(&range.end, |r| r.start) {
            Ok(0) => None,
@@ -439,33 +406,10 @@ pub struct KeyPartitioning {
    pub parts: Vec<KeySpace>,
 }

-/// Represents a partitioning of the sparse key space.
-#[derive(Clone, Debug, Default)]
-pub struct SparseKeyPartitioning {
-    pub parts: Vec<SparseKeySpace>,
-}
-
 impl KeyPartitioning {
    pub fn new() -> Self {
        KeyPartitioning { parts: Vec::new() }
    }
-
-    /// Convert a key partitioning to a sparse partition.
-    pub fn into_sparse(self) -> SparseKeyPartitioning {
-        SparseKeyPartitioning {
-            parts: self.parts.into_iter().map(SparseKeySpace).collect(),
-        }
-    }
-}
-
-impl SparseKeyPartitioning {
-    /// Note: use this function with caution. Attempt to handle a sparse keyspace in the same way as a dense keyspace will
-    /// cause long/dead loops.
-    pub fn into_dense(self) -> KeyPartitioning {
-        KeyPartitioning {
-            parts: self.parts.into_iter().map(|x| x.0).collect(),
-        }
-    }
 }

 ///
@@ -593,8 +537,6 @@ pub fn singleton_range(key: Key) -> Range<Key> {

 #[cfg(test)]
 mod tests {
-    use rand::{RngCore, SeedableRng};
-
    use crate::{
        models::ShardParameters,
        shard::{ShardCount, ShardNumber},
@@ -990,35 +932,6 @@ mod tests {
        assert_eq!(range.page_count(), 1);
    }

-    /// Test the helper that we use to identify ranges which go outside the data blocks of a single relation
-    #[test]
-    fn contiguous_range_check() {
-        assert!(!is_contiguous_range(
-            &(Key::from_hex("000000067f00000001000004df00fffffffe").unwrap()
-                ..Key::from_hex("000000067f00000001000004df0100000003").unwrap())
-        ),);
-
-        // The ranges goes all the way up to the 0xffffffff, including it: this is
-        // not considered a rel block range because 0xffffffff stores logical sizes,
-        // not blocks.
-        assert!(!is_contiguous_range(
-            &(Key::from_hex("000000067f00000001000004df00fffffffe").unwrap()
-                ..Key::from_hex("000000067f00000001000004df0100000000").unwrap())
-        ),);
-
-        // Keys within the normal data region of a relation
-        assert!(is_contiguous_range(
-            &(Key::from_hex("000000067f00000001000004df0000000000").unwrap()
-                ..Key::from_hex("000000067f00000001000004df0000000080").unwrap())
-        ),);
-
-        // The logical size key of one forkno, then some blocks in the next
-        assert!(is_contiguous_range(
-            &(Key::from_hex("000000067f00000001000004df00ffffffff").unwrap()
-                ..Key::from_hex("000000067f00000001000004df0100000080").unwrap())
-        ),);
-    }
-
    #[test]
    fn shard_identity_keyspaces_forkno_gap() {
        let shard_identity = ShardIdentity::new(
@@ -1036,10 +949,10 @@ mod tests {
            &shard_identity,
        );

-        // Range spanning the end of one forkno and the start of the next: we do not attempt to
-        // calculate a valid size, because we have no way to know if they keys between start
-        // and end are actually in use.
-        assert_eq!(range.page_count(), u32::MAX);
+        // Range spanning the end of one forkno and the start of the next, but not intersecting this shard's stripes
+        // This is technically an under-count, as the logical size key would be stored on this shard, but that's okay
+        // because page_count is allowed to under-count: it just mustn't over-count.
+        assert_eq!(range.page_count(), 0);
    }

    #[test]
@@ -1092,10 +1005,6 @@ mod tests {
        // Invariant: we always get at least one fragment
        assert!(!fragments.is_empty());

-        // Invariant: the first/last fragment start/end should equal the input start/end
-        assert_eq!(fragments.first().unwrap().1.start, range_start);
-        assert_eq!(fragments.last().unwrap().1.end, range_end);
-
        if page_count > 0 {
            // Invariant: every fragment must contain at least one shard-local page, if the
            // total range contains at least one shard-local page
@@ -1109,21 +1018,6 @@ mod tests {
            assert_eq!(fragments, vec![(0, range_start..range_end)]);
        }

-        // Invariant: fragments must be ordered and non-overlapping
-        let mut last: Option<Range<Key>> = None;
-        for frag in &fragments {
-            if let Some(last) = last {
-                assert!(frag.1.start >= last.end);
-                assert!(frag.1.start > last.start);
-            }
-            last = Some(frag.1.clone())
-        }
-
-        // Invariant: fragments respect target_nblocks
-        for frag in &fragments {
-            assert!(frag.0 == u32::MAX || frag.0 <= target_nblocks);
-        }
-
        (page_count, fragments)
    }

@@ -1206,39 +1100,6 @@ mod tests {
        );
    }

-    /// Test our calculations work correctly when we start a range from the logical size key of
-    /// a previous relation.
-    #[test]
-    fn sharded_range_fragment_starting_from_logical_size() {
-        let input_start = Key::from_hex("000000067f00000001000000ae00ffffffff").unwrap();
-        let input_end = Key::from_hex("000000067f00000001000000ae0100008000").unwrap();
-
-        // Shard 0 owns the first stripe in the relation, and the preceding logical size is shard local too
-        let shard_identity = ShardIdentity::new(
-            ShardNumber(0),
-            ShardCount::new(4),
-            ShardParameters::DEFAULT_STRIPE_SIZE,
-        )
-        .unwrap();
-        assert_eq!(
-            do_fragment(input_start, input_end, &shard_identity, 0x10000),
-            (0x8001, vec![(0x8001, input_start..input_end)])
-        );
-
-        // Shard 1 does not own the first stripe in the relation, but it does own the logical size (all shards
-        // store all logical sizes)
-        let shard_identity = ShardIdentity::new(
-            ShardNumber(1),
-            ShardCount::new(4),
-            ShardParameters::DEFAULT_STRIPE_SIZE,
-        )
-        .unwrap();
-        assert_eq!(
-            do_fragment(input_start, input_end, &shard_identity, 0x10000),
-            (0x1, vec![(0x1, input_start..input_end)])
-        );
-    }
-
    /// Test that ShardedRange behaves properly when used on un-sharded data
    #[test]
    fn sharded_range_fragment_unsharded() {
@@ -1282,79 +1143,4 @@ mod tests {
            (u32::MAX, vec![(u32::MAX, input_start..input_end),])
        );
    }
-
-    #[test]
-    fn sharded_range_fragment_tiny_nblocks() {
-        let shard_identity = ShardIdentity::unsharded();
-
-        // A range that spans relations: expect fragmentation to give up and return a u32::MAX size
-        let input_start = Key::from_hex("000000067F00000001000004E10000000000").unwrap();
-        let input_end = Key::from_hex("000000067F00000001000004E10000000038").unwrap();
-        assert_eq!(
-            do_fragment(input_start, input_end, &shard_identity, 16),
-            (
-                0x38,
-                vec![
-                    (16, input_start..input_start.add(16)),
-                    (16, input_start.add(16)..input_start.add(32)),
-                    (16, input_start.add(32)..input_start.add(48)),
-                    (8, input_start.add(48)..input_end),
-                ]
-            )
-        );
-    }
-
-    #[test]
-    fn sharded_range_fragment_fuzz() {
-        // Use a fixed seed: we don't want to explicitly pick values, but we do want
-        // the test to be reproducible.
-        let mut prng = rand::rngs::StdRng::seed_from_u64(0xdeadbeef);
-
-        for _i in 0..1000 {
-            let shard_identity = if prng.next_u32() % 2 == 0 {
-                ShardIdentity::unsharded()
-            } else {
-                let shard_count = prng.next_u32() % 127 + 1;
-                ShardIdentity::new(
-                    ShardNumber((prng.next_u32() % shard_count) as u8),
-                    ShardCount::new(shard_count as u8),
-                    ShardParameters::DEFAULT_STRIPE_SIZE,
-                )
-                .unwrap()
-            };
-
-            let target_nblocks = prng.next_u32() % 65536 + 1;
-
-            let start_offset = prng.next_u32() % 16384;
-
-            // Try ranges up to 4GiB in size, that are always at least 1
-            let range_size = prng.next_u32() % 8192 + 1;
-
-            // A range that spans relations: expect fragmentation to give up and return a u32::MAX size
-            let input_start = Key::from_hex("000000067F00000001000004E10000000000")
-                .unwrap()
-                .add(start_offset);
-            let input_end = input_start.add(range_size);
-
-            // This test's main success conditions are the invariants baked into do_fragment
-            let (_total_size, fragments) =
-                do_fragment(input_start, input_end, &shard_identity, target_nblocks);
-
-            // Pick a random key within the range and check it appears in the output
-            let example_key = input_start.add(prng.next_u32() % range_size);
-
-            // Panic on unwrap if it isn't found
-            let example_key_frag = fragments
-                .iter()
-                .find(|f| f.1.contains(&example_key))
-                .unwrap();
-
-            // Check that the fragment containing our random key has a nonzero size if
-            // that key is shard-local
-            let example_key_local = !shard_identity.is_key_disposable(&example_key);
-            if example_key_local {
-                assert!(example_key_frag.0 > 0);
-            }
-        }
-    }
 }
--- a/libs/pageserver_api/src/lib.rs
+++ b/libs/pageserver_api/src/lib.rs
@@ -1,5 +1,6 @@
 #![deny(unsafe_code)]
 #![deny(clippy::undocumented_unsafe_blocks)]
+use const_format::formatcp;

 pub mod controller_api;
 pub mod key;
@@ -10,4 +11,7 @@ pub mod shard;
 /// Public API types
 pub mod upcall_api;

-pub mod config;
+pub const DEFAULT_PG_LISTEN_PORT: u16 = 64000;
+pub const DEFAULT_PG_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_PG_LISTEN_PORT}");
+pub const DEFAULT_HTTP_LISTEN_PORT: u16 = 9898;
+pub const DEFAULT_HTTP_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_HTTP_LISTEN_PORT}");
--- a/libs/pageserver_api/src/models.rs
+++ b/libs/pageserver_api/src/models.rs
@@ -303,7 +303,6 @@ pub struct TenantConfig {
    pub lazy_slru_download: Option<bool>,
    pub timeline_get_throttle: Option<ThrottleConfig>,
    pub image_layer_creation_check_threshold: Option<u8>,
-    pub switch_to_aux_file_v2: Option<bool>,
 }

 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
@@ -430,6 +429,8 @@ pub struct StatusResponse {
 #[derive(Serialize, Deserialize, Debug)]
 #[serde(deny_unknown_fields)]
 pub struct TenantLocationConfigRequest {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tenant_id: Option<TenantShardId>,
    #[serde(flatten)]
    pub config: LocationConfig, // as we have a flattened field, we should reject all unknown fields in it
 }
@@ -780,17 +781,6 @@ pub struct SecondaryProgress {
    pub bytes_total: u64,
 }

-#[derive(Serialize, Deserialize, Debug)]
-pub struct TenantScanRemoteStorageShard {
-    pub tenant_shard_id: TenantShardId,
-    pub generation: Option<u32>,
-}
-
-#[derive(Serialize, Deserialize, Debug, Default)]
-pub struct TenantScanRemoteStorageResponse {
-    pub shards: Vec<TenantScanRemoteStorageShard>,
-}
-
 pub mod virtual_file {
    #[derive(
        Copy,
@@ -858,72 +848,39 @@ impl TryFrom<u8> for PagestreamBeMessageTag {
    }
 }

-// In the V2 protocol version, a GetPage request contains two LSN values:
-//
-// request_lsn: Get the page version at this point in time.  Lsn::Max is a special value that means
-// "get the latest version present". It's used by the primary server, which knows that no one else
-// is writing WAL. 'not_modified_since' must be set to a proper value even if request_lsn is
-// Lsn::Max. Standby servers use the current replay LSN as the request LSN.
-//
-// not_modified_since: Hint to the pageserver that the client knows that the page has not been
-// modified between 'not_modified_since' and the request LSN. It's always correct to set
-// 'not_modified_since equal' to 'request_lsn' (unless Lsn::Max is used as the 'request_lsn'), but
-// passing an earlier LSN can speed up the request, by allowing the pageserver to process the
-// request without waiting for 'request_lsn' to arrive.
-//
-// The legacy V1 interface contained only one LSN, and a boolean 'latest' flag. The V1 interface was
-// sufficient for the primary; the 'lsn' was equivalent to the 'not_modified_since' value, and
-// 'latest' was set to true. The V2 interface was added because there was no correct way for a
-// standby to request a page at a particular non-latest LSN, and also include the
-// 'not_modified_since' hint. That led to an awkward choice of either using an old LSN in the
-// request, if the standby knows that the page hasn't been modified since, and risk getting an error
-// if that LSN has fallen behind the GC horizon, or requesting the current replay LSN, which could
-// require the pageserver unnecessarily to wait for the WAL to arrive up to that point. The new V2
-// interface allows sending both LSNs, and let the pageserver do the right thing. There is no
-// difference in the responses between V1 and V2.
-//
-// The Request structs below reflect the V2 interface. If V1 is used, the parse function
-// maps the old format requests to the new format.
-//
-#[derive(Clone, Copy)]
-pub enum PagestreamProtocolVersion {
-    V1,
-    V2,
-}
-
 #[derive(Debug, PartialEq, Eq)]
 pub struct PagestreamExistsRequest {
-    pub request_lsn: Lsn,
-    pub not_modified_since: Lsn,
+    pub latest: bool,
+    pub lsn: Lsn,
    pub rel: RelTag,
 }

 #[derive(Debug, PartialEq, Eq)]
 pub struct PagestreamNblocksRequest {
-    pub request_lsn: Lsn,
-    pub not_modified_since: Lsn,
+    pub latest: bool,
+    pub lsn: Lsn,
    pub rel: RelTag,
 }

 #[derive(Debug, PartialEq, Eq)]
 pub struct PagestreamGetPageRequest {
-    pub request_lsn: Lsn,
-    pub not_modified_since: Lsn,
+    pub latest: bool,
+    pub lsn: Lsn,
    pub rel: RelTag,
    pub blkno: u32,
 }

 #[derive(Debug, PartialEq, Eq)]
 pub struct PagestreamDbSizeRequest {
-    pub request_lsn: Lsn,
-    pub not_modified_since: Lsn,
+    pub latest: bool,
+    pub lsn: Lsn,
    pub dbnode: u32,
 }

 #[derive(Debug, PartialEq, Eq)]
 pub struct PagestreamGetSlruSegmentRequest {
-    pub request_lsn: Lsn,
-    pub not_modified_since: Lsn,
+    pub latest: bool,
+    pub lsn: Lsn,
    pub kind: u8,
    pub segno: u32,
 }
@@ -970,16 +927,14 @@ pub struct TenantHistorySize {
 }

 impl PagestreamFeMessage {
-    /// Serialize a compute -> pageserver message. This is currently only used in testing
-    /// tools. Always uses protocol version 2.
    pub fn serialize(&self) -> Bytes {
        let mut bytes = BytesMut::new();

        match self {
            Self::Exists(req) => {
                bytes.put_u8(0);
-                bytes.put_u64(req.request_lsn.0);
-                bytes.put_u64(req.not_modified_since.0);
+                bytes.put_u8(u8::from(req.latest));
+                bytes.put_u64(req.lsn.0);
                bytes.put_u32(req.rel.spcnode);
                bytes.put_u32(req.rel.dbnode);
                bytes.put_u32(req.rel.relnode);
@@ -988,8 +943,8 @@ impl PagestreamFeMessage {

            Self::Nblocks(req) => {
                bytes.put_u8(1);
-                bytes.put_u64(req.request_lsn.0);
-                bytes.put_u64(req.not_modified_since.0);
+                bytes.put_u8(u8::from(req.latest));
+                bytes.put_u64(req.lsn.0);
                bytes.put_u32(req.rel.spcnode);
                bytes.put_u32(req.rel.dbnode);
                bytes.put_u32(req.rel.relnode);
@@ -998,8 +953,8 @@ impl PagestreamFeMessage {

            Self::GetPage(req) => {
                bytes.put_u8(2);
-                bytes.put_u64(req.request_lsn.0);
-                bytes.put_u64(req.not_modified_since.0);
+                bytes.put_u8(u8::from(req.latest));
+                bytes.put_u64(req.lsn.0);
                bytes.put_u32(req.rel.spcnode);
                bytes.put_u32(req.rel.dbnode);
                bytes.put_u32(req.rel.relnode);
@@ -1009,15 +964,15 @@ impl PagestreamFeMessage {

            Self::DbSize(req) => {
                bytes.put_u8(3);
-                bytes.put_u64(req.request_lsn.0);
-                bytes.put_u64(req.not_modified_since.0);
+                bytes.put_u8(u8::from(req.latest));
+                bytes.put_u64(req.lsn.0);
                bytes.put_u32(req.dbnode);
            }

            Self::GetSlruSegment(req) => {
                bytes.put_u8(4);
-                bytes.put_u64(req.request_lsn.0);
-                bytes.put_u64(req.not_modified_since.0);
+                bytes.put_u8(u8::from(req.latest));
+                bytes.put_u64(req.lsn.0);
                bytes.put_u8(req.kind);
                bytes.put_u32(req.segno);
            }
@@ -1026,40 +981,18 @@ impl PagestreamFeMessage {
        bytes.into()
    }

-    pub fn parse<R: std::io::Read>(
-        body: &mut R,
-        protocol_version: PagestreamProtocolVersion,
-    ) -> anyhow::Result<PagestreamFeMessage> {
+    pub fn parse<R: std::io::Read>(body: &mut R) -> anyhow::Result<PagestreamFeMessage> {
+        // TODO these gets can fail
+
        // these correspond to the NeonMessageTag enum in pagestore_client.h
        //
        // TODO: consider using protobuf or serde bincode for less error prone
        // serialization.
        let msg_tag = body.read_u8()?;
-
-        let (request_lsn, not_modified_since) = match protocol_version {
-            PagestreamProtocolVersion::V2 => (
-                Lsn::from(body.read_u64::<BigEndian>()?),
-                Lsn::from(body.read_u64::<BigEndian>()?),
-            ),
-            PagestreamProtocolVersion::V1 => {
-                // In the old protocol, each message starts with a boolean 'latest' flag,
-                // followed by 'lsn'. Convert that to the two LSNs, 'request_lsn' and
-                // 'not_modified_since', used in the new protocol version.
-                let latest = body.read_u8()? != 0;
-                let request_lsn = Lsn::from(body.read_u64::<BigEndian>()?);
-                if latest {
-                    (Lsn::MAX, request_lsn) // get latest version
-                } else {
-                    (request_lsn, request_lsn) // get version at specified LSN
-                }
-            }
-        };
-
-        // The rest of the messages are the same between V1 and V2
        match msg_tag {
            0 => Ok(PagestreamFeMessage::Exists(PagestreamExistsRequest {
-                request_lsn,
-                not_modified_since,
+                latest: body.read_u8()? != 0,
+                lsn: Lsn::from(body.read_u64::<BigEndian>()?),
                rel: RelTag {
                    spcnode: body.read_u32::<BigEndian>()?,
                    dbnode: body.read_u32::<BigEndian>()?,
@@ -1068,8 +1001,8 @@ impl PagestreamFeMessage {
                },
            })),
            1 => Ok(PagestreamFeMessage::Nblocks(PagestreamNblocksRequest {
-                request_lsn,
-                not_modified_since,
+                latest: body.read_u8()? != 0,
+                lsn: Lsn::from(body.read_u64::<BigEndian>()?),
                rel: RelTag {
                    spcnode: body.read_u32::<BigEndian>()?,
                    dbnode: body.read_u32::<BigEndian>()?,
@@ -1078,8 +1011,8 @@ impl PagestreamFeMessage {
                },
            })),
            2 => Ok(PagestreamFeMessage::GetPage(PagestreamGetPageRequest {
-                request_lsn,
-                not_modified_since,
+                latest: body.read_u8()? != 0,
+                lsn: Lsn::from(body.read_u64::<BigEndian>()?),
                rel: RelTag {
                    spcnode: body.read_u32::<BigEndian>()?,
                    dbnode: body.read_u32::<BigEndian>()?,
@@ -1089,14 +1022,14 @@ impl PagestreamFeMessage {
                blkno: body.read_u32::<BigEndian>()?,
            })),
            3 => Ok(PagestreamFeMessage::DbSize(PagestreamDbSizeRequest {
-                request_lsn,
-                not_modified_since,
+                latest: body.read_u8()? != 0,
+                lsn: Lsn::from(body.read_u64::<BigEndian>()?),
                dbnode: body.read_u32::<BigEndian>()?,
            })),
            4 => Ok(PagestreamFeMessage::GetSlruSegment(
                PagestreamGetSlruSegmentRequest {
-                    request_lsn,
-                    not_modified_since,
+                    latest: body.read_u8()? != 0,
+                    lsn: Lsn::from(body.read_u64::<BigEndian>()?),
                    kind: body.read_u8()?,
                    segno: body.read_u32::<BigEndian>()?,
                },
@@ -1224,8 +1157,8 @@ mod tests {
        // Test serialization/deserialization of PagestreamFeMessage
        let messages = vec![
            PagestreamFeMessage::Exists(PagestreamExistsRequest {
-                request_lsn: Lsn(4),
-                not_modified_since: Lsn(3),
+                latest: true,
+                lsn: Lsn(4),
                rel: RelTag {
                    forknum: 1,
                    spcnode: 2,
@@ -1234,8 +1167,8 @@ mod tests {
                },
            }),
            PagestreamFeMessage::Nblocks(PagestreamNblocksRequest {
-                request_lsn: Lsn(4),
-                not_modified_since: Lsn(4),
+                latest: false,
+                lsn: Lsn(4),
                rel: RelTag {
                    forknum: 1,
                    spcnode: 2,
@@ -1244,8 +1177,8 @@ mod tests {
                },
            }),
            PagestreamFeMessage::GetPage(PagestreamGetPageRequest {
-                request_lsn: Lsn(4),
-                not_modified_since: Lsn(3),
+                latest: true,
+                lsn: Lsn(4),
                rel: RelTag {
                    forknum: 1,
                    spcnode: 2,
@@ -1255,16 +1188,14 @@ mod tests {
                blkno: 7,
            }),
            PagestreamFeMessage::DbSize(PagestreamDbSizeRequest {
-                request_lsn: Lsn(4),
-                not_modified_since: Lsn(3),
+                latest: true,
+                lsn: Lsn(4),
                dbnode: 7,
            }),
        ];
        for msg in messages {
            let bytes = msg.serialize();
-            let reconstructed =
-                PagestreamFeMessage::parse(&mut bytes.reader(), PagestreamProtocolVersion::V2)
-                    .unwrap();
+            let reconstructed = PagestreamFeMessage::parse(&mut bytes.reader()).unwrap();
            assert!(msg == reconstructed);
        }
    }
--- a/libs/pageserver_api/src/models/partitioning.rs
+++ b/libs/pageserver_api/src/models/partitioning.rs
@@ -1,11 +1,9 @@
 use utils::lsn::Lsn;

-use crate::keyspace::SparseKeySpace;
-
 #[derive(Debug, PartialEq, Eq)]
 pub struct Partitioning {
    pub keys: crate::keyspace::KeySpace,
-    pub sparse_keys: crate::keyspace::SparseKeySpace,
+
    pub at_lsn: Lsn,
 }

@@ -34,8 +32,6 @@ impl serde::Serialize for Partitioning {
        let mut map = serializer.serialize_map(Some(2))?;
        map.serialize_key("keys")?;
        map.serialize_value(&KeySpace(&self.keys))?;
-        map.serialize_key("sparse_keys")?;
-        map.serialize_value(&KeySpace(&self.sparse_keys.0))?;
        map.serialize_key("at_lsn")?;
        map.serialize_value(&WithDisplay(&self.at_lsn))?;
        map.end()
@@ -103,7 +99,6 @@ impl<'a> serde::Deserialize<'a> for Partitioning {
        #[derive(serde::Deserialize)]
        struct De {
            keys: KeySpace,
-            sparse_keys: KeySpace,
            #[serde_as(as = "serde_with::DisplayFromStr")]
            at_lsn: Lsn,
        }
@@ -112,7 +107,6 @@ impl<'a> serde::Deserialize<'a> for Partitioning {
        Ok(Self {
            at_lsn: de.at_lsn,
            keys: de.keys.0,
-            sparse_keys: SparseKeySpace(de.sparse_keys.0),
        })
    }
 }
@@ -139,12 +133,6 @@ mod tests {
                "030000000000000000000000000000000003"
              ]
            ],
-            "sparse_keys": [
-              [
-                "620000000000000000000000000000000000",
-                "620000000000000000000000000000000003"
-              ]
-            ],
            "at_lsn": "0/2240160"
        }
        "#;
--- a/libs/pageserver_api/src/shard.rs
+++ b/libs/pageserver_api/src/shard.rs
@@ -97,7 +97,7 @@ impl ShardCount {

    /// The internal value of a ShardCount may be zero, which means "1 shard, but use
    /// legacy format for TenantShardId that excludes the shard suffix", also known
-    /// as [`TenantShardId::unsharded`].
+    /// as `TenantShardId::unsharded`.
    ///
    /// This method returns the actual number of shards, i.e. if our internal value is
    /// zero, we return 1 (unsharded tenants have 1 shard).
@@ -116,9 +116,7 @@ impl ShardCount {
        self.0
    }

-    /// Whether the `ShardCount` is for an unsharded tenant, so uses one shard but
-    /// uses the legacy format for `TenantShardId`. See also the documentation for
-    /// [`Self::count`].
+    ///
    pub fn is_unsharded(&self) -> bool {
        self.0 == 0
    }
@@ -540,6 +538,24 @@ impl ShardIdentity {
        }
    }

+    /// Special case for issue `<https://github.com/neondatabase/neon/issues/7451>`
+    ///
+    /// When we fail to read a forknum block, this function tells us whether we may ignore the error
+    /// as a symptom of that issue.
+    pub fn is_key_buggy_forknum(&self, key: &Key) -> bool {
+        if !is_rel_block_key(key) || key.field5 != INIT_FORKNUM {
+            return false;
+        }
+
+        let mut hash = murmurhash32(key.field4);
+        hash = hash_combine(hash, murmurhash32(key.field6 / self.stripe_size.0));
+        let mapped_shard = ShardNumber((hash % self.count.0 as u32) as u8);
+
+        // The key may be affected by issue #7454: it is an initfork and it would not
+        // have mapped to shard 0 until we fixed that issue.
+        mapped_shard != ShardNumber(0)
+    }
+
    /// Return true if the key should be discarded if found in this shard's
    /// data store, e.g. during compaction after a split.
    ///
--- a/libs/postgres_ffi/src/xlog_utils.rs
+++ b/libs/postgres_ffi/src/xlog_utils.rs
@@ -331,10 +331,7 @@ impl CheckPoint {
    /// Returns 'true' if the XID was updated.
    pub fn update_next_xid(&mut self, xid: u32) -> bool {
        // nextXid should be greater than any XID in WAL, so increment provided XID and check for wraparround.
-        let mut new_xid = std::cmp::max(
-            xid.wrapping_add(1),
-            pg_constants::FIRST_NORMAL_TRANSACTION_ID,
-        );
+        let mut new_xid = std::cmp::max(xid.wrapping_add(1), pg_constants::FIRST_NORMAL_TRANSACTION_ID);
        // To reduce number of metadata checkpoints, we forward align XID on XID_CHECKPOINT_INTERVAL.
        // XID_CHECKPOINT_INTERVAL should not be larger than BLCKSZ*CLOG_XACTS_PER_BYTE
        new_xid =
@@ -370,16 +367,8 @@ pub fn generate_wal_segment(segno: u64, system_id: u64, lsn: Lsn) -> Result<Byte
    let seg_off = lsn.segment_offset(WAL_SEGMENT_SIZE);

    let first_page_only = seg_off < XLOG_BLCKSZ;
-    // If first records starts in the middle of the page, pretend in page header
-    // there is a fake record which ends where first real record starts. This
-    // makes pg_waldump etc happy.
-    let (shdr_rem_len, infoflags) = if first_page_only && seg_off > 0 {
-        assert!(seg_off >= XLOG_SIZE_OF_XLOG_LONG_PHD);
-        // xlp_rem_len doesn't include page header, hence the subtraction.
-        (
-            seg_off - XLOG_SIZE_OF_XLOG_LONG_PHD,
-            pg_constants::XLP_FIRST_IS_CONTRECORD,
-        )
+    let (shdr_rem_len, infoflags) = if first_page_only {
+        (seg_off, pg_constants::XLP_FIRST_IS_CONTRECORD)
    } else {
        (0, 0)
    };
@@ -408,22 +397,20 @@ pub fn generate_wal_segment(segno: u64, system_id: u64, lsn: Lsn) -> Result<Byte

    if !first_page_only {
        let block_offset = lsn.page_offset_in_segment(WAL_SEGMENT_SIZE) as usize;
-        // see comments above about XLP_FIRST_IS_CONTRECORD and xlp_rem_len.
-        let (xlp_rem_len, xlp_info) = if page_off > 0 {
-            assert!(page_off >= XLOG_SIZE_OF_XLOG_SHORT_PHD as u64);
-            (
-                (page_off - XLOG_SIZE_OF_XLOG_SHORT_PHD as u64) as u32,
-                pg_constants::XLP_FIRST_IS_CONTRECORD,
-            )
-        } else {
-            (0, 0)
-        };
        let header = XLogPageHeaderData {
            xlp_magic: XLOG_PAGE_MAGIC as u16,
-            xlp_info,
+            xlp_info: if page_off >= pg_constants::SIZE_OF_PAGE_HEADER as u64 {
+                pg_constants::XLP_FIRST_IS_CONTRECORD
+            } else {
+                0
+            },
            xlp_tli: PG_TLI,
            xlp_pageaddr: lsn.page_lsn().0,
-            xlp_rem_len,
+            xlp_rem_len: if page_off >= pg_constants::SIZE_OF_PAGE_HEADER as u64 {
+                page_off as u32
+            } else {
+                0u32
+            },
            ..Default::default() // Put 0 in padding fields.
        };
        let hdr_bytes = header.encode()?;
--- a/libs/remote_storage/Cargo.toml
+++ b/libs/remote_storage/Cargo.toml
@@ -38,7 +38,6 @@ azure_storage_blobs.workspace = true
 futures-util.workspace = true
 http-types.workspace = true
 itertools.workspace = true
-sync_wrapper = { workspace = true, features = ["futures"] }

 [dev-dependencies]
 camino-tempfile.workspace = true
--- a/libs/remote_storage/src/azure_blob.rs
+++ b/libs/remote_storage/src/azure_blob.rs
@@ -3,7 +3,6 @@
 use std::borrow::Cow;
 use std::collections::HashMap;
 use std::env;
-use std::io;
 use std::num::NonZeroU32;
 use std::pin::Pin;
 use std::str::FromStr;
@@ -21,7 +20,6 @@ use azure_storage_blobs::blob::CopyStatus;
 use azure_storage_blobs::prelude::ClientBuilder;
 use azure_storage_blobs::{blob::operations::GetBlobBuilder, prelude::ContainerClient};
 use bytes::Bytes;
-use futures::future::Either;
 use futures::stream::Stream;
 use futures_util::StreamExt;
 use futures_util::TryStreamExt;
@@ -130,12 +128,12 @@ impl AzureBlobStorage {
        let kind = RequestKind::Get;

        let _permit = self.permit(kind, cancel).await?;
-        let cancel_or_timeout = crate::support::cancel_or_timeout(self.timeout, cancel.clone());
-        let cancel_or_timeout_ = crate::support::cancel_or_timeout(self.timeout, cancel.clone());

        let mut etag = None;
        let mut last_modified = None;
        let mut metadata = HashMap::new();
+        // TODO give proper streaming response instead of buffering into RAM
+        // https://github.com/neondatabase/neon/issues/5563

        let download = async {
            let response = builder
@@ -154,46 +152,39 @@ impl AzureBlobStorage {
                Err(_elapsed) => Err(DownloadError::Timeout),
            });

-            let mut response = Box::pin(response);
+            let mut response = std::pin::pin!(response);

-            let Some(part) = response.next().await else {
+            let mut bufs = Vec::new();
+            while let Some(part) = response.next().await {
+                let part = part?;
+                if etag.is_none() {
+                    etag = Some(part.blob.properties.etag);
+                }
+                if last_modified.is_none() {
+                    last_modified = Some(part.blob.properties.last_modified.into());
+                }
+                if let Some(blob_meta) = part.blob.metadata {
+                    metadata.extend(blob_meta.iter().map(|(k, v)| (k.to_owned(), v.to_owned())));
+                }
+                let data = part
+                    .data
+                    .collect()
+                    .await
+                    .map_err(|e| DownloadError::Other(e.into()))?;
+                bufs.push(data);
+            }
+
+            if bufs.is_empty() {
                return Err(DownloadError::Other(anyhow::anyhow!(
-                    "Azure GET response contained no response body"
+                    "Azure GET response contained no buffers"
                )));
-            };
-            let part = part?;
-            if etag.is_none() {
-                etag = Some(part.blob.properties.etag);
            }
-            if last_modified.is_none() {
-                last_modified = Some(part.blob.properties.last_modified.into());
-            }
-            if let Some(blob_meta) = part.blob.metadata {
-                metadata.extend(blob_meta.iter().map(|(k, v)| (k.to_owned(), v.to_owned())));
-            }
-
            // unwrap safety: if these were None, bufs would be empty and we would have returned an error already
            let etag = etag.unwrap();
            let last_modified = last_modified.unwrap();

-            let tail_stream = response
-                .map(|part| match part {
-                    Ok(part) => Either::Left(part.data.map(|r| r.map_err(io::Error::other))),
-                    Err(e) => {
-                        Either::Right(futures::stream::once(async { Err(io::Error::other(e)) }))
-                    }
-                })
-                .flatten();
-            let stream = part
-                .data
-                .map(|r| r.map_err(io::Error::other))
-                .chain(sync_wrapper::SyncStream::new(tail_stream));
-            //.chain(SyncStream::from_pin(Box::pin(tail_stream)));
-
-            let download_stream = crate::support::DownloadStream::new(cancel_or_timeout_, stream);
-
            Ok(Download {
-                download_stream: Box::pin(download_stream),
+                download_stream: Box::pin(futures::stream::iter(bufs.into_iter().map(Ok))),
                etag,
                last_modified,
                metadata: Some(StorageMetadata(metadata)),
@@ -202,10 +193,7 @@ impl AzureBlobStorage {

        tokio::select! {
            bufs = download => bufs,
-            cancel_or_timeout = cancel_or_timeout => match cancel_or_timeout {
-                TimeoutOrCancel::Timeout => Err(DownloadError::Timeout),
-                TimeoutOrCancel::Cancel => Err(DownloadError::Cancelled),
-            },
+            _ = cancel.cancelled() => Err(DownloadError::Cancelled),
        }
    }

--- a/libs/remote_storage/src/lib.rs
+++ b/libs/remote_storage/src/lib.rs
@@ -55,11 +55,11 @@ pub use error::{DownloadError, TimeTravelError, TimeoutOrCancel};
 /// ~3500 PUT/COPY/POST/DELETE or 5500 GET/HEAD S3 requests
 /// <https://aws.amazon.com/premiumsupport/knowledge-center/s3-request-limit-avoid-throttling/>
 pub const DEFAULT_REMOTE_STORAGE_S3_CONCURRENCY_LIMIT: usize = 100;
-/// Set this limit analogously to the S3 limit
+/// We set this a little bit low as we currently buffer the entire file into RAM
 ///
 /// Here, a limit of max 20k concurrent connections was noted.
 /// <https://learn.microsoft.com/en-us/answers/questions/1301863/is-there-any-limitation-to-concurrent-connections>
-pub const DEFAULT_REMOTE_STORAGE_AZURE_CONCURRENCY_LIMIT: usize = 100;
+pub const DEFAULT_REMOTE_STORAGE_AZURE_CONCURRENCY_LIMIT: usize = 30;
 /// No limits on the client side, which currenltly means 1000 for AWS S3.
 /// <https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectsV2.html#API_ListObjectsV2_RequestSyntax>
 pub const DEFAULT_MAX_KEYS_PER_LIST_RESPONSE: Option<i32> = None;
--- a/libs/utils/src/generation.rs
+++ b/libs/utils/src/generation.rs
@@ -34,8 +34,6 @@ pub enum Generation {
 /// scenarios where pageservers might otherwise issue conflicting writes to
 /// remote storage
 impl Generation {
-    pub const MAX: Self = Self::Valid(u32::MAX);
-
    /// Create a new Generation that represents a legacy key format with
    /// no generation suffix
    pub fn none() -> Self {
--- a/libs/utils/src/seqwait.rs
+++ b/libs/utils/src/seqwait.rs
@@ -2,10 +2,11 @@

 use std::cmp::{Eq, Ordering};
 use std::collections::BinaryHeap;
+use std::fmt::Debug;
 use std::mem;
 use std::sync::Mutex;
 use std::time::Duration;
-use tokio::sync::watch::{self, channel};
+use tokio::sync::watch::{channel, Receiver, Sender};
 use tokio::time::timeout;

 /// An error happened while waiting for a number
@@ -34,73 +35,23 @@ pub trait MonotonicCounter<V> {
    fn cnt_value(&self) -> V;
 }

-/// Heap of waiters, lowest numbers pop first.
-struct Waiters<V>
+/// Internal components of a `SeqWait`
+struct SeqWaitInt<S, V>
 where
+    S: MonotonicCounter<V>,
    V: Ord,
 {
-    heap: BinaryHeap<Waiter<V>>,
-    /// Number of the first waiter in the heap, or None if there are no waiters.
-    status_channel: watch::Sender<Option<V>>,
-}
-
-impl<V> Waiters<V>
-where
-    V: Ord + Copy,
-{
-    fn new() -> Self {
-        Waiters {
-            heap: BinaryHeap::new(),
-            status_channel: channel(None).0,
-        }
-    }
-
-    /// `status_channel` contains the number of the first waiter in the heap.
-    /// This function should be called whenever waiters heap changes.
-    fn update_status(&self) {
-        let first_waiter = self.heap.peek().map(|w| w.wake_num);
-        let _ = self.status_channel.send_replace(first_waiter);
-    }
-
-    /// Add new waiter to the heap, return a channel that will be notified when the number arrives.
-    fn add(&mut self, num: V) -> watch::Receiver<()> {
-        let (tx, rx) = channel(());
-        self.heap.push(Waiter {
-            wake_num: num,
-            wake_channel: tx,
-        });
-        self.update_status();
-        rx
-    }
-
-    /// Pop all waiters <= num from the heap. Collect channels in a vector,
-    /// so that caller can wake them up.
-    fn pop_leq(&mut self, num: V) -> Vec<watch::Sender<()>> {
-        let mut wake_these = Vec::new();
-        while let Some(n) = self.heap.peek() {
-            if n.wake_num > num {
-                break;
-            }
-            wake_these.push(self.heap.pop().unwrap().wake_channel);
-        }
-        self.update_status();
-        wake_these
-    }
-
-    /// Used on shutdown to efficiently drop all waiters.
-    fn take_all(&mut self) -> BinaryHeap<Waiter<V>> {
-        let heap = mem::take(&mut self.heap);
-        self.update_status();
-        heap
-    }
+    waiters: BinaryHeap<Waiter<V>>,
+    current: S,
+    shutdown: bool,
 }

 struct Waiter<T>
 where
    T: Ord,
 {
-    wake_num: T,                     // wake me when this number arrives ...
-    wake_channel: watch::Sender<()>, // ... by sending a message to this channel
+    wake_num: T,              // wake me when this number arrives ...
+    wake_channel: Sender<()>, // ... by sending a message to this channel
 }

 // BinaryHeap is a max-heap, and we want a min-heap. Reverse the ordering here
@@ -125,17 +76,6 @@ impl<T: Ord> PartialEq for Waiter<T> {

 impl<T: Ord> Eq for Waiter<T> {}

-/// Internal components of a `SeqWait`
-struct SeqWaitInt<S, V>
-where
-    S: MonotonicCounter<V>,
-    V: Ord,
-{
-    waiters: Waiters<V>,
-    current: S,
-    shutdown: bool,
-}
-
 /// A tool for waiting on a sequence number
 ///
 /// This provides a way to wait the arrival of a number.
@@ -168,7 +108,7 @@ where
    /// Create a new `SeqWait`, initialized to a particular number
    pub fn new(starting_num: S) -> Self {
        let internal = SeqWaitInt {
-            waiters: Waiters::new(),
+            waiters: BinaryHeap::new(),
            current: starting_num,
            shutdown: false,
        };
@@ -188,8 +128,9 @@ where
            // Block any future waiters from starting
            internal.shutdown = true;

-            // Take all waiters to drop them later.
-            internal.waiters.take_all()
+            // This will steal the entire waiters map.
+            // When we drop it all waiters will be woken.
+            mem::take(&mut internal.waiters)

            // Drop the lock as we exit this scope.
        };
@@ -255,7 +196,7 @@ where

    /// Register and return a channel that will be notified when a number arrives,
    /// or None, if it has already arrived.
-    fn queue_for_wait(&self, num: V) -> Result<Option<watch::Receiver<()>>, SeqWaitError> {
+    fn queue_for_wait(&self, num: V) -> Result<Option<Receiver<()>>, SeqWaitError> {
        let mut internal = self.internal.lock().unwrap();
        if internal.current.cnt_value() >= num {
            return Ok(None);
@@ -264,8 +205,12 @@ where
            return Err(SeqWaitError::Shutdown);
        }

-        // Add waiter channel to the queue.
-        let rx = internal.waiters.add(num);
+        // Create a new channel.
+        let (tx, rx) = channel(());
+        internal.waiters.push(Waiter {
+            wake_num: num,
+            wake_channel: tx,
+        });
        // Drop the lock as we exit this scope.
        Ok(Some(rx))
    }
@@ -286,8 +231,16 @@ where
            }
            internal.current.cnt_advance(num);

-            // Pop all waiters <= num from the heap.
-            internal.waiters.pop_leq(num)
+            // Pop all waiters <= num from the heap. Collect them in a vector, and
+            // wake them up after releasing the lock.
+            let mut wake_these = Vec::new();
+            while let Some(n) = internal.waiters.peek() {
+                if n.wake_num > num {
+                    break;
+                }
+                wake_these.push(internal.waiters.pop().unwrap().wake_channel);
+            }
+            wake_these
        };

        for tx in wake_these {
@@ -302,23 +255,6 @@ where
    pub fn load(&self) -> S {
        self.internal.lock().unwrap().current
    }
-
-    /// Get a Receiver for the current status.
-    ///
-    /// The current status is the number of the first waiter in the queue,
-    /// or None if there are no waiters.
-    ///
-    /// This receiver will be notified whenever the status changes.
-    /// It is useful for receiving notifications when the first waiter
-    /// starts waiting for a number, or when there are no more waiters left.
-    pub fn status_receiver(&self) -> watch::Receiver<Option<V>> {
-        self.internal
-            .lock()
-            .unwrap()
-            .waiters
-            .status_channel
-            .subscribe()
-    }
 }

 #[cfg(test)]
--- a/libs/walproposer/src/api_bindings.rs
+++ b/libs/walproposer/src/api_bindings.rs
@@ -50,14 +50,6 @@ extern "C" fn get_flush_rec_ptr(wp: *mut WalProposer) -> XLogRecPtr {
    }
 }

-extern "C" fn update_donor(wp: *mut WalProposer, donor: *mut Safekeeper, donor_lsn: XLogRecPtr) {
-    unsafe {
-        let callback_data = (*(*wp).config).callback_data;
-        let api = callback_data as *mut Box<dyn ApiImpl>;
-        (*api).update_donor(&mut (*donor), donor_lsn)
-    }
-}
-
 extern "C" fn get_current_timestamp(wp: *mut WalProposer) -> TimestampTz {
    unsafe {
        let callback_data = (*(*wp).config).callback_data;
@@ -399,7 +391,6 @@ pub(crate) fn create_api() -> walproposer_api {
        get_shmem_state: Some(get_shmem_state),
        start_streaming: Some(start_streaming),
        get_flush_rec_ptr: Some(get_flush_rec_ptr),
-        update_donor: Some(update_donor),
        get_current_timestamp: Some(get_current_timestamp),
        conn_error_message: Some(conn_error_message),
        conn_status: Some(conn_status),
@@ -430,32 +421,6 @@ pub(crate) fn create_api() -> walproposer_api {
    }
 }

-pub fn empty_shmem() -> crate::bindings::WalproposerShmemState {
-    let empty_feedback = crate::bindings::PageserverFeedback {
-        present: false,
-        currentClusterSize: 0,
-        last_received_lsn: 0,
-        disk_consistent_lsn: 0,
-        remote_consistent_lsn: 0,
-        replytime: 0,
-        shard_number: 0,
-    };
-
-    crate::bindings::WalproposerShmemState {
-        propEpochStartLsn: crate::bindings::pg_atomic_uint64 { value: 0 },
-        donor_name: [0; 64],
-        donor_conninfo: [0; 1024],
-        donor_lsn: 0,
-        mutex: 0,
-        mineLastElectedTerm: crate::bindings::pg_atomic_uint64 { value: 0 },
-        backpressureThrottlingTime: crate::bindings::pg_atomic_uint64 { value: 0 },
-        currentClusterSize: crate::bindings::pg_atomic_uint64 { value: 0 },
-        shard_ps_feedback: [empty_feedback; 128],
-        num_shards: 0,
-        min_ps_feedback: empty_feedback,
-    }
-}
-
 impl std::fmt::Display for Level {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        write!(f, "{:?}", self)
--- a/libs/walproposer/src/walproposer.rs
+++ b/libs/walproposer/src/walproposer.rs
@@ -1,5 +1,8 @@
 use std::ffi::CString;

+use postgres_ffi::WAL_SEGMENT_SIZE;
+use utils::{id::TenantTimelineId, lsn::Lsn};
+
 use crate::{
    api_bindings::{create_api, take_vec_u8, Level},
    bindings::{
@@ -7,8 +10,6 @@ use crate::{
        WalProposerCreate, WalProposerFree, WalProposerPoll, WalProposerStart,
    },
 };
-use postgres_ffi::WAL_SEGMENT_SIZE;
-use utils::{id::TenantTimelineId, lsn::Lsn};

 /// Rust high-level wrapper for C walproposer API. Many methods are not required
 /// for simple cases, hence todo!() in default implementations.
@@ -27,10 +28,6 @@ pub trait ApiImpl {
        todo!()
    }

-    fn update_donor(&self, _donor: &mut Safekeeper, _donor_lsn: u64) {
-        todo!()
-    }
-
    fn get_current_timestamp(&self) -> i64 {
        todo!()
    }
@@ -277,7 +274,6 @@ mod tests {
        sync::{atomic::AtomicUsize, mpsc::sync_channel},
    };

-    use std::cell::UnsafeCell;
    use utils::id::TenantTimelineId;

    use crate::{api_bindings::Level, bindings::NeonWALReadResult, walproposer::Wrapper};
@@ -301,8 +297,6 @@ mod tests {
        replies_ptr: AtomicUsize,
        // channel to send LSN to the main thread
        sync_channel: std::sync::mpsc::SyncSender<u64>,
-        // Shmem state, used for storing donor info
-        shmem: UnsafeCell<crate::bindings::WalproposerShmemState>,
    }

    impl MockImpl {
@@ -333,22 +327,11 @@ mod tests {
    }

    impl ApiImpl for MockImpl {
-        fn get_shmem_state(&self) -> *mut crate::bindings::WalproposerShmemState {
-            self.shmem.get()
-        }
-
        fn get_current_timestamp(&self) -> i64 {
            println!("get_current_timestamp");
            0
        }

-        fn update_donor(&self, donor: &mut crate::bindings::Safekeeper, donor_lsn: u64) {
-            let mut shmem = unsafe { *self.get_shmem_state() };
-            shmem.propEpochStartLsn.value = donor_lsn;
-            shmem.donor_conninfo = donor.conninfo;
-            shmem.donor_lsn = donor_lsn;
-        }
-
        fn conn_status(
            &self,
            _: &mut crate::bindings::Safekeeper,
@@ -524,7 +507,6 @@ mod tests {
            ],
            replies_ptr: AtomicUsize::new(0),
            sync_channel: sender,
-            shmem: UnsafeCell::new(crate::api_bindings::empty_shmem()),
        });
        let config = crate::walproposer::Config {
            ttid,
--- a/pageserver/client/src/mgmt_api.rs
+++ b/pageserver/client/src/mgmt_api.rs
@@ -243,19 +243,6 @@ impl Client {
        Ok(())
    }

-    pub async fn tenant_scan_remote_storage(
-        &self,
-        tenant_id: TenantId,
-    ) -> Result<TenantScanRemoteStorageResponse> {
-        let uri = format!(
-            "{}/v1/tenant/{tenant_id}/scan_remote_storage",
-            self.mgmt_api_endpoint
-        );
-        let response = self.request(Method::GET, &uri, ()).await?;
-        let body = response.json().await.map_err(Error::ReceiveBody)?;
-        Ok(body)
-    }
-
    pub async fn tenant_config(&self, req: &TenantConfigRequest) -> Result<()> {
        let uri = format!("{}/v1/tenant/config", self.mgmt_api_endpoint);
        self.request(Method::PUT, &uri, req).await?;
@@ -284,34 +271,6 @@ impl Client {
        Ok((status, progress))
    }

-    pub async fn tenant_secondary_status(
-        &self,
-        tenant_shard_id: TenantShardId,
-    ) -> Result<SecondaryProgress> {
-        let path = reqwest::Url::parse(&format!(
-            "{}/v1/tenant/{}/secondary/status",
-            self.mgmt_api_endpoint, tenant_shard_id
-        ))
-        .expect("Cannot build URL");
-
-        self.request(Method::GET, path, ())
-            .await?
-            .json()
-            .await
-            .map_err(Error::ReceiveBody)
-    }
-
-    pub async fn tenant_heatmap_upload(&self, tenant_id: TenantShardId) -> Result<()> {
-        let path = reqwest::Url::parse(&format!(
-            "{}/v1/tenant/{}/heatmap_upload",
-            self.mgmt_api_endpoint, tenant_id
-        ))
-        .expect("Cannot build URL");
-
-        self.request(Method::POST, path, ()).await?;
-        Ok(())
-    }
-
    pub async fn location_config(
        &self,
        tenant_shard_id: TenantShardId,
@@ -319,7 +278,10 @@ impl Client {
        flush_ms: Option<std::time::Duration>,
        lazy: bool,
    ) -> Result<()> {
-        let req_body = TenantLocationConfigRequest { config };
+        let req_body = TenantLocationConfigRequest {
+            tenant_id: None,
+            config,
+        };

        let mut path = reqwest::Url::parse(&format!(
            "{}/v1/tenant/{}/location_config",
--- a/pageserver/client/src/page_service.rs
+++ b/pageserver/client/src/page_service.rs
@@ -60,7 +60,7 @@ impl Client {
    ) -> anyhow::Result<PagestreamClient> {
        let copy_both: tokio_postgres::CopyBothDuplex<bytes::Bytes> = self
            .client
-            .copy_both_simple(&format!("pagestream_v2 {tenant_id} {timeline_id}"))
+            .copy_both_simple(&format!("pagestream {tenant_id} {timeline_id}"))
            .await?;
        let Client {
            cancel_on_client_drop,
--- a/pageserver/pagebench/src/cmd/getpage_latest_lsn.rs
+++ b/pageserver/pagebench/src/cmd/getpage_latest_lsn.rs
@@ -312,12 +312,8 @@ async fn main_impl(
                    let (rel_tag, block_no) =
                        key_to_rel_block(key).expect("we filter non-rel-block keys out above");
                    PagestreamGetPageRequest {
-                        request_lsn: if rng.gen_bool(args.req_latest_probability) {
-                            Lsn::MAX
-                        } else {
-                            r.timeline_lsn
-                        },
-                        not_modified_since: r.timeline_lsn,
+                        latest: rng.gen_bool(args.req_latest_probability),
+                        lsn: r.timeline_lsn,
                        rel: rel_tag,
                        blkno: block_no,
                    }
--- a/pageserver/src/aux_file.rs
+++ b/pageserver/src/aux_file.rs
@@ -85,27 +85,27 @@ mod tests {
        // To correct retrieve AUX files, the generated keys for the same file must be the same for all versions
        // of the page server.
        assert_eq!(
-            "6200000101E5B20C5F8DD5AA3289D6D9EAFA",
+            "8200000101E5B20C5F8DD5AA3289D6D9EAFA",
            encode_aux_file_key("pg_logical/mappings/test1").to_string()
        );
        assert_eq!(
-            "620000010239AAC544893139B26F501B97E6",
+            "820000010239AAC544893139B26F501B97E6",
            encode_aux_file_key("pg_logical/snapshots/test2").to_string()
        );
        assert_eq!(
-            "620000010300000000000000000000000000",
+            "820000010300000000000000000000000000",
            encode_aux_file_key("pg_logical/replorigin_checkpoint").to_string()
        );
        assert_eq!(
-            "62000001FF8635AF2134B7266EC5B4189FD6",
+            "82000001FF8635AF2134B7266EC5B4189FD6",
            encode_aux_file_key("pg_logical/unsupported").to_string()
        );
        assert_eq!(
-            "6200000201772D0E5D71DE14DA86142A1619",
+            "8200000201772D0E5D71DE14DA86142A1619",
            encode_aux_file_key("pg_replslot/test3").to_string()
        );
        assert_eq!(
-            "620000FFFF1866EBEB53B807B26A2416F317",
+            "820000FFFF1866EBEB53B807B26A2416F317",
            encode_aux_file_key("other_file_not_supported").to_string()
        );
    }
--- a/pageserver/src/basebackup.rs
+++ b/pageserver/src/basebackup.rs
@@ -10,10 +10,10 @@
 //! This module is responsible for creation of such tarball
 //! from data stored in object storage.
 //!
-use anyhow::{anyhow, Context};
+use anyhow::{anyhow, bail, ensure, Context};
 use bytes::{BufMut, Bytes, BytesMut};
 use fail::fail_point;
-use pageserver_api::key::{key_to_slru_block, Key};
+use pageserver_api::key::{key_to_slru_block, rel_block_to_key, Key};
 use postgres_ffi::pg_constants;
 use std::fmt::Write as FmtWrite;
 use std::time::SystemTime;
@@ -38,14 +38,6 @@ use postgres_ffi::PG_TLI;
 use postgres_ffi::{BLCKSZ, RELSEG_SIZE, WAL_SEGMENT_SIZE};
 use utils::lsn::Lsn;

-#[derive(Debug, thiserror::Error)]
-pub enum BasebackupError {
-    #[error("basebackup pageserver error {0:#}")]
-    Server(#[from] anyhow::Error),
-    #[error("basebackup client error {0:#}")]
-    Client(#[source] io::Error),
-}
-
 /// Create basebackup with non-rel data in it.
 /// Only include relational data if 'full_backup' is true.
 ///
@@ -61,7 +53,7 @@ pub async fn send_basebackup_tarball<'a, W>(
    prev_lsn: Option<Lsn>,
    full_backup: bool,
    ctx: &'a RequestContext,
-) -> Result<(), BasebackupError>
+) -> anyhow::Result<()>
 where
    W: AsyncWrite + Send + Sync + Unpin,
 {
@@ -100,10 +92,8 @@ where

    // Consolidate the derived and the provided prev_lsn values
    let prev_lsn = if let Some(provided_prev_lsn) = prev_lsn {
-        if backup_prev != Lsn(0) && backup_prev != provided_prev_lsn {
-            return Err(BasebackupError::Server(anyhow!(
-                "backup_prev {backup_prev} != provided_prev_lsn {provided_prev_lsn}"
-            )));
+        if backup_prev != Lsn(0) {
+            ensure!(backup_prev == provided_prev_lsn);
        }
        provided_prev_lsn
    } else {
@@ -169,26 +159,15 @@ where
        }
    }

-    async fn add_block(&mut self, key: &Key, block: Bytes) -> Result<(), BasebackupError> {
+    async fn add_block(&mut self, key: &Key, block: Bytes) -> anyhow::Result<()> {
        let (kind, segno, _) = key_to_slru_block(*key)?;

        match kind {
            SlruKind::Clog => {
-                if !(block.len() == BLCKSZ as usize || block.len() == BLCKSZ as usize + 8) {
-                    return Err(BasebackupError::Server(anyhow!(
-                        "invalid SlruKind::Clog record: block.len()={}",
-                        block.len()
-                    )));
-                }
+                ensure!(block.len() == BLCKSZ as usize || block.len() == BLCKSZ as usize + 8);
            }
            SlruKind::MultiXactMembers | SlruKind::MultiXactOffsets => {
-                if block.len() != BLCKSZ as usize {
-                    return Err(BasebackupError::Server(anyhow!(
-                        "invalid {:?} record: block.len()={}",
-                        kind,
-                        block.len()
-                    )));
-                }
+                ensure!(block.len() == BLCKSZ as usize);
            }
        }

@@ -215,15 +194,12 @@ where
        Ok(())
    }

-    async fn flush(&mut self) -> Result<(), BasebackupError> {
+    async fn flush(&mut self) -> anyhow::Result<()> {
        let nblocks = self.buf.len() / BLCKSZ as usize;
        let (kind, segno) = self.current_segment.take().unwrap();
        let segname = format!("{}/{:>04X}", kind.to_str(), segno);
        let header = new_tar_header(&segname, self.buf.len() as u64)?;
-        self.ar
-            .append(&header, self.buf.as_slice())
-            .await
-            .map_err(BasebackupError::Client)?;
+        self.ar.append(&header, self.buf.as_slice()).await?;

        self.total_blocks += nblocks;
        debug!("Added to basebackup slru {} relsize {}", segname, nblocks);
@@ -233,7 +209,7 @@ where
        Ok(())
    }

-    async fn finish(mut self) -> Result<(), BasebackupError> {
+    async fn finish(mut self) -> anyhow::Result<()> {
        let res = if self.current_segment.is_none() || self.buf.is_empty() {
            Ok(())
        } else {
@@ -250,7 +226,7 @@ impl<'a, W> Basebackup<'a, W>
 where
    W: AsyncWrite + Send + Sync + Unpin,
 {
-    async fn send_tarball(mut self) -> Result<(), BasebackupError> {
+    async fn send_tarball(mut self) -> anyhow::Result<()> {
        // TODO include checksum

        let lazy_slru_download = self.timeline.get_lazy_slru_download() && !self.full_backup;
@@ -286,8 +262,7 @@ where
            let slru_partitions = self
                .timeline
                .get_slru_keyspace(Version::Lsn(self.lsn), self.ctx)
-                .await
-                .map_err(|e| BasebackupError::Server(e.into()))?
+                .await?
                .partition(
                    self.timeline.get_shard_identity(),
                    Timeline::MAX_GET_VECTORED_KEYS * BLCKSZ as u64,
@@ -296,15 +271,10 @@ where
            let mut slru_builder = SlruSegmentsBuilder::new(&mut self.ar);

            for part in slru_partitions.parts {
-                let blocks = self
-                    .timeline
-                    .get_vectored(part, self.lsn, self.ctx)
-                    .await
-                    .map_err(|e| BasebackupError::Server(e.into()))?;
+                let blocks = self.timeline.get_vectored(part, self.lsn, self.ctx).await?;

                for (key, block) in blocks {
-                    let block = block.map_err(|e| BasebackupError::Server(e.into()))?;
-                    slru_builder.add_block(&key, block).await?;
+                    slru_builder.add_block(&key, block?).await?;
                }
            }
            slru_builder.finish().await?;
@@ -312,11 +282,8 @@ where

        let mut min_restart_lsn: Lsn = Lsn::MAX;
        // Create tablespace directories
-        for ((spcnode, dbnode), has_relmap_file) in self
-            .timeline
-            .list_dbdirs(self.lsn, self.ctx)
-            .await
-            .map_err(|e| BasebackupError::Server(e.into()))?
+        for ((spcnode, dbnode), has_relmap_file) in
+            self.timeline.list_dbdirs(self.lsn, self.ctx).await?
        {
            self.add_dbdir(spcnode, dbnode, has_relmap_file).await?;

@@ -325,8 +292,7 @@ where
            let rels = self
                .timeline
                .list_rels(spcnode, dbnode, Version::Lsn(self.lsn), self.ctx)
-                .await
-                .map_err(|e| BasebackupError::Server(e.into()))?;
+                .await?;
            for &rel in rels.iter() {
                // Send init fork as main fork to provide well formed empty
                // contents of UNLOGGED relations. Postgres copies it in
@@ -334,7 +300,20 @@ where
                if rel.forknum == INIT_FORKNUM {
                    // I doubt we need _init fork itself, but having it at least
                    // serves as a marker relation is unlogged.
-                    self.add_rel(rel, rel).await?;
+                    if let Err(_e) = self.add_rel(rel, rel).await {
+                        if self
+                            .timeline
+                            .get_shard_identity()
+                            .is_key_buggy_forknum(&rel_block_to_key(rel, 0x0))
+                        {
+                            // Workaround https://github.com/neondatabase/neon/issues/7451 -- if we have an unlogged relation
+                            // whose INIT_FORKNUM is not correctly on shard zero, then omit it in the basebackup.  This allows
+                            // postgres to start up.  The relation won't work, but it will be possible to DROP TABLE on it and
+                            // recreate.
+                            tracing::warn!("Omitting relation {rel} for issue #7451: drop and recreate this unlogged relation");
+                            continue;
+                        }
+                    };
                    self.add_rel(rel, rel.with_forknum(MAIN_FORKNUM)).await?;
                    continue;
                }
@@ -349,12 +328,7 @@ where
                }
            }

-            for (path, content) in self
-                .timeline
-                .list_aux_files(self.lsn, self.ctx)
-                .await
-                .map_err(|e| BasebackupError::Server(e.into()))?
-            {
+            for (path, content) in self.timeline.list_aux_files(self.lsn, self.ctx).await? {
                if path.starts_with("pg_replslot") {
                    let offs = pg_constants::REPL_SLOT_ON_DISK_OFFSETOF_RESTART_LSN;
                    let restart_lsn = Lsn(u64::from_le_bytes(
@@ -385,41 +359,34 @@ where
        for xid in self
            .timeline
            .list_twophase_files(self.lsn, self.ctx)
-            .await
-            .map_err(|e| BasebackupError::Server(e.into()))?
+            .await?
        {
            self.add_twophase_file(xid).await?;
        }

        fail_point!("basebackup-before-control-file", |_| {
-            Err(BasebackupError::Server(anyhow!(
-                "failpoint basebackup-before-control-file"
-            )))
+            bail!("failpoint basebackup-before-control-file")
        });

        // Generate pg_control and bootstrap WAL segment.
        self.add_pgcontrol_file().await?;
-        self.ar.finish().await.map_err(BasebackupError::Client)?;
+        self.ar.finish().await?;
        debug!("all tarred up!");
        Ok(())
    }

    /// Add contents of relfilenode `src`, naming it as `dst`.
-    async fn add_rel(&mut self, src: RelTag, dst: RelTag) -> Result<(), BasebackupError> {
+    async fn add_rel(&mut self, src: RelTag, dst: RelTag) -> anyhow::Result<()> {
        let nblocks = self
            .timeline
-            .get_rel_size(src, Version::Lsn(self.lsn), self.ctx)
-            .await
-            .map_err(|e| BasebackupError::Server(e.into()))?;
+            .get_rel_size(src, Version::Lsn(self.lsn), false, self.ctx)
+            .await?;

        // If the relation is empty, create an empty file
        if nblocks == 0 {
            let file_name = dst.to_segfile_name(0);
            let header = new_tar_header(&file_name, 0)?;
-            self.ar
-                .append(&header, &mut io::empty())
-                .await
-                .map_err(BasebackupError::Client)?;
+            self.ar.append(&header, &mut io::empty()).await?;
            return Ok(());
        }

@@ -433,18 +400,14 @@ where
            for blknum in startblk..endblk {
                let img = self
                    .timeline
-                    .get_rel_page_at_lsn(src, blknum, Version::Lsn(self.lsn), self.ctx)
-                    .await
-                    .map_err(|e| BasebackupError::Server(e.into()))?;
+                    .get_rel_page_at_lsn(src, blknum, Version::Lsn(self.lsn), false, self.ctx)
+                    .await?;
                segment_data.extend_from_slice(&img[..]);
            }

            let file_name = dst.to_segfile_name(seg as u32);
            let header = new_tar_header(&file_name, segment_data.len() as u64)?;
-            self.ar
-                .append(&header, segment_data.as_slice())
-                .await
-                .map_err(BasebackupError::Client)?;
+            self.ar.append(&header, segment_data.as_slice()).await?;

            seg += 1;
            startblk = endblk;
@@ -464,22 +427,20 @@ where
        spcnode: u32,
        dbnode: u32,
        has_relmap_file: bool,
-    ) -> Result<(), BasebackupError> {
+    ) -> anyhow::Result<()> {
        let relmap_img = if has_relmap_file {
            let img = self
                .timeline
                .get_relmap_file(spcnode, dbnode, Version::Lsn(self.lsn), self.ctx)
-                .await
-                .map_err(|e| BasebackupError::Server(e.into()))?;
+                .await?;

-            if img.len()
-                != dispatch_pgversion!(self.timeline.pg_version, pgv::bindings::SIZEOF_RELMAPFILE)
-            {
-                return Err(BasebackupError::Server(anyhow!(
-                    "img.len() != SIZE_OF_RELMAPFILE, img.len()={}",
-                    img.len(),
-                )));
-            }
+            ensure!(
+                img.len()
+                    == dispatch_pgversion!(
+                        self.timeline.pg_version,
+                        pgv::bindings::SIZEOF_RELMAPFILE
+                    )
+            );

            Some(img)
        } else {
@@ -492,20 +453,14 @@ where
                ver => format!("{ver}\x0A"),
            };
            let header = new_tar_header("PG_VERSION", pg_version_str.len() as u64)?;
-            self.ar
-                .append(&header, pg_version_str.as_bytes())
-                .await
-                .map_err(BasebackupError::Client)?;
+            self.ar.append(&header, pg_version_str.as_bytes()).await?;

            info!("timeline.pg_version {}", self.timeline.pg_version);

            if let Some(img) = relmap_img {
                // filenode map for global tablespace
                let header = new_tar_header("global/pg_filenode.map", img.len() as u64)?;
-                self.ar
-                    .append(&header, &img[..])
-                    .await
-                    .map_err(BasebackupError::Client)?;
+                self.ar.append(&header, &img[..]).await?;
            } else {
                warn!("global/pg_filenode.map is missing");
            }
@@ -524,26 +479,18 @@ where
                && self
                    .timeline
                    .list_rels(spcnode, dbnode, Version::Lsn(self.lsn), self.ctx)
-                    .await
-                    .map_err(|e| BasebackupError::Server(e.into()))?
+                    .await?
                    .is_empty()
            {
                return Ok(());
            }
            // User defined tablespaces are not supported
-            if spcnode != DEFAULTTABLESPACE_OID {
-                return Err(BasebackupError::Server(anyhow!(
-                    "spcnode != DEFAULTTABLESPACE_OID, spcnode={spcnode}"
-                )));
-            }
+            ensure!(spcnode == DEFAULTTABLESPACE_OID);

            // Append dir path for each database
            let path = format!("base/{}", dbnode);
            let header = new_tar_header_dir(&path)?;
-            self.ar
-                .append(&header, &mut io::empty())
-                .await
-                .map_err(BasebackupError::Client)?;
+            self.ar.append(&header, &mut io::empty()).await?;

            if let Some(img) = relmap_img {
                let dst_path = format!("base/{}/PG_VERSION", dbnode);
@@ -553,17 +500,11 @@ where
                    ver => format!("{ver}\x0A"),
                };
                let header = new_tar_header(&dst_path, pg_version_str.len() as u64)?;
-                self.ar
-                    .append(&header, pg_version_str.as_bytes())
-                    .await
-                    .map_err(BasebackupError::Client)?;
+                self.ar.append(&header, pg_version_str.as_bytes()).await?;

                let relmap_path = format!("base/{}/pg_filenode.map", dbnode);
                let header = new_tar_header(&relmap_path, img.len() as u64)?;
-                self.ar
-                    .append(&header, &img[..])
-                    .await
-                    .map_err(BasebackupError::Client)?;
+                self.ar.append(&header, &img[..]).await?;
            }
        };
        Ok(())
@@ -572,12 +513,11 @@ where
    //
    // Extract twophase state files
    //
-    async fn add_twophase_file(&mut self, xid: TransactionId) -> Result<(), BasebackupError> {
+    async fn add_twophase_file(&mut self, xid: TransactionId) -> anyhow::Result<()> {
        let img = self
            .timeline
            .get_twophase_file(xid, self.lsn, self.ctx)
-            .await
-            .map_err(|e| BasebackupError::Server(e.into()))?;
+            .await?;

        let mut buf = BytesMut::new();
        buf.extend_from_slice(&img[..]);
@@ -585,10 +525,7 @@ where
        buf.put_u32_le(crc);
        let path = format!("pg_twophase/{:>08X}", xid);
        let header = new_tar_header(&path, buf.len() as u64)?;
-        self.ar
-            .append(&header, &buf[..])
-            .await
-            .map_err(BasebackupError::Client)?;
+        self.ar.append(&header, &buf[..]).await?;

        Ok(())
    }
@@ -597,28 +534,24 @@ where
    // Add generated pg_control file and bootstrap WAL segment.
    // Also send zenith.signal file with extra bootstrap data.
    //
-    async fn add_pgcontrol_file(&mut self) -> Result<(), BasebackupError> {
+    async fn add_pgcontrol_file(&mut self) -> anyhow::Result<()> {
        // add zenith.signal file
        let mut zenith_signal = String::new();
        if self.prev_record_lsn == Lsn(0) {
            if self.lsn == self.timeline.get_ancestor_lsn() {
-                write!(zenith_signal, "PREV LSN: none")
-                    .map_err(|e| BasebackupError::Server(e.into()))?;
+                write!(zenith_signal, "PREV LSN: none")?;
            } else {
-                write!(zenith_signal, "PREV LSN: invalid")
-                    .map_err(|e| BasebackupError::Server(e.into()))?;
+                write!(zenith_signal, "PREV LSN: invalid")?;
            }
        } else {
-            write!(zenith_signal, "PREV LSN: {}", self.prev_record_lsn)
-                .map_err(|e| BasebackupError::Server(e.into()))?;
+            write!(zenith_signal, "PREV LSN: {}", self.prev_record_lsn)?;
        }
        self.ar
            .append(
                &new_tar_header("zenith.signal", zenith_signal.len() as u64)?,
                zenith_signal.as_bytes(),
            )
-            .await
-            .map_err(BasebackupError::Client)?;
+            .await?;

        let checkpoint_bytes = self
            .timeline
@@ -640,10 +573,7 @@ where

        //send pg_control
        let header = new_tar_header("global/pg_control", pg_control_bytes.len() as u64)?;
-        self.ar
-            .append(&header, &pg_control_bytes[..])
-            .await
-            .map_err(BasebackupError::Client)?;
+        self.ar.append(&header, &pg_control_bytes[..]).await?;

        //send wal segment
        let segno = self.lsn.segment_number(WAL_SEGMENT_SIZE);
@@ -658,16 +588,8 @@ where
            self.lsn,
        )
        .map_err(|e| anyhow!(e).context("Failed generating wal segment"))?;
-        if wal_seg.len() != WAL_SEGMENT_SIZE {
-            return Err(BasebackupError::Server(anyhow!(
-                "wal_seg.len() != WAL_SEGMENT_SIZE, wal_seg.len()={}",
-                wal_seg.len()
-            )));
-        }
-        self.ar
-            .append(&header, &wal_seg[..])
-            .await
-            .map_err(BasebackupError::Client)?;
+        ensure!(wal_seg.len() == WAL_SEGMENT_SIZE);
+        self.ar.append(&header, &wal_seg[..]).await?;
        Ok(())
    }
 }
--- a/pageserver/src/bin/pageserver.rs
+++ b/pageserver/src/bin/pageserver.rs
@@ -3,7 +3,6 @@
 //! Main entry point for the Page Server executable.

 use std::env::{var, VarError};
-use std::io::Read;
 use std::sync::Arc;
 use std::time::Duration;
 use std::{env, ops::ControlFlow, str::FromStr};
@@ -152,34 +151,37 @@ fn initialize_config(
    workdir: &Utf8Path,
 ) -> anyhow::Result<ControlFlow<(), &'static PageServerConf>> {
    let init = arg_matches.get_flag("init");
+    let update_config = init || arg_matches.get_flag("update-config");

-    let file_contents: Option<toml_edit::Document> = match std::fs::File::open(cfg_file_path) {
-        Ok(mut f) => {
-            if init {
-                anyhow::bail!("config file already exists: {cfg_file_path}");
-            }
-            let md = f.metadata().context("stat config file")?;
-            if md.is_file() {
-                let mut s = String::new();
-                f.read_to_string(&mut s).context("read config file")?;
-                Some(s.parse().context("parse config file toml")?)
-            } else {
-                anyhow::bail!("directory entry exists but is not a file: {cfg_file_path}");
-            }
-        }
-        Err(e) if e.kind() == std::io::ErrorKind::NotFound => None,
-        Err(e) => {
-            anyhow::bail!("open pageserver config: {e}: {cfg_file_path}");
+    let (mut toml, config_file_exists) = if cfg_file_path.is_file() {
+        if init {
+            anyhow::bail!(
+                "Config file '{cfg_file_path}' already exists, cannot init it, use --update-config to update it",
+            );
        }
+        // Supplement the CLI arguments with the config file
+        let cfg_file_contents = std::fs::read_to_string(cfg_file_path)
+            .with_context(|| format!("Failed to read pageserver config at '{cfg_file_path}'"))?;
+        (
+            cfg_file_contents
+                .parse::<toml_edit::Document>()
+                .with_context(|| {
+                    format!("Failed to parse '{cfg_file_path}' as pageserver config")
+                })?,
+            true,
+        )
+    } else if cfg_file_path.exists() {
+        anyhow::bail!("Config file '{cfg_file_path}' exists but is not a regular file");
+    } else {
+        // We're initializing the tenant, so there's no config file yet
+        (
+            DEFAULT_CONFIG_FILE
+                .parse::<toml_edit::Document>()
+                .context("could not parse built-in config file")?,
+            false,
+        )
    };

-    let mut effective_config = file_contents.unwrap_or_else(|| {
-        DEFAULT_CONFIG_FILE
-            .parse()
-            .expect("unit tests ensure this works")
-    });
-
-    // Patch with overrides from the command line
    if let Some(values) = arg_matches.get_many::<String>("config-override") {
        for option_line in values {
            let doc = toml_edit::Document::from_str(option_line).with_context(|| {
@@ -187,21 +189,22 @@ fn initialize_config(
            })?;

            for (key, item) in doc.iter() {
-                effective_config.insert(key, item.clone());
+                if config_file_exists && update_config && key == "id" && toml.contains_key(key) {
+                    anyhow::bail!("Pageserver config file exists at '{cfg_file_path}' and has node id already, it cannot be overridden");
+                }
+                toml.insert(key, item.clone());
            }
        }
    }

-    debug!("Resulting toml: {effective_config}");
-
-    // Construct the runtime representation
-    let conf = PageServerConf::parse_and_validate(&effective_config, workdir)
+    debug!("Resulting toml: {toml}");
+    let conf = PageServerConf::parse_and_validate(&toml, workdir)
        .context("Failed to parse pageserver configuration")?;

-    if init {
+    if update_config {
        info!("Writing pageserver config to '{cfg_file_path}'");

-        std::fs::write(cfg_file_path, effective_config.to_string())
+        std::fs::write(cfg_file_path, toml.to_string())
            .with_context(|| format!("Failed to write pageserver config to '{cfg_file_path}'"))?;
        info!("Config successfully written to '{cfg_file_path}'")
    }
@@ -755,13 +758,18 @@ fn cli() -> Command {
        // See `settings.md` for more details on the extra configuration patameters pageserver can process
        .arg(
            Arg::new("config-override")
-                .long("config-override")
                .short('c')
                .num_args(1)
                .action(ArgAction::Append)
                .help("Additional configuration overrides of the ones from the toml config file (or new ones to add there). \
                Any option has to be a valid toml document, example: `-c=\"foo='hey'\"` `-c=\"foo={value=1}\"`"),
        )
+        .arg(
+            Arg::new("update-config")
+                .long("update-config")
+                .action(ArgAction::SetTrue)
+                .help("Update the config file when started"),
+        )
        .arg(
            Arg::new("enabled-features")
                .long("enabled-features")
--- a/pageserver/src/config.rs
+++ b/pageserver/src/config.rs
@@ -9,7 +9,7 @@ use pageserver_api::shard::TenantShardId;
 use remote_storage::{RemotePath, RemoteStorageConfig};
 use serde;
 use serde::de::IntoDeserializer;
-use std::env;
+use std::{collections::HashMap, env};
 use storage_broker::Uri;
 use utils::crashsafe::path_with_suffix_extension;
 use utils::id::ConnectionId;
@@ -51,7 +51,7 @@ pub mod defaults {
    use crate::tenant::config::defaults::*;
    use const_format::formatcp;

-    pub use pageserver_api::config::{
+    pub use pageserver_api::{
        DEFAULT_HTTP_LISTEN_ADDR, DEFAULT_HTTP_LISTEN_PORT, DEFAULT_PG_LISTEN_ADDR,
        DEFAULT_PG_LISTEN_PORT,
    };
@@ -335,6 +335,26 @@ impl<T: Clone> BuilderValue<T> {
    }
 }

+// Certain metadata (e.g. externally-addressable name, AZ) is delivered
+// as a separate structure.  This information is not neeed by the pageserver
+// itself, it is only used for registering the pageserver with the control
+// plane and/or storage controller.
+//
+#[derive(serde::Deserialize)]
+pub(crate) struct NodeMetadata {
+    #[serde(rename = "host")]
+    pub(crate) postgres_host: String,
+    #[serde(rename = "port")]
+    pub(crate) postgres_port: u16,
+    pub(crate) http_host: String,
+    pub(crate) http_port: u16,
+
+    // Deployment tools may write fields to the metadata file beyond what we
+    // use in this type: this type intentionally only names fields that require.
+    #[serde(flatten)]
+    pub(crate) other: HashMap<String, serde_json::Value>,
+}
+
 // needed to simplify config construction
 #[derive(Default)]
 struct PageServerConfigBuilder {
--- a/pageserver/src/control_plane_client.rs
+++ b/pageserver/src/control_plane_client.rs
@@ -14,8 +14,10 @@ use tokio_util::sync::CancellationToken;
 use url::Url;
 use utils::{backoff, failpoint_support, generation::Generation, id::NodeId};

-use crate::{config::PageServerConf, virtual_file::on_fatal_io_error};
-use pageserver_api::config::NodeMetadata;
+use crate::{
+    config::{NodeMetadata, PageServerConf},
+    virtual_file::on_fatal_io_error,
+};

 /// The Pageserver's client for using the control plane API: this is a small subset
 /// of the overall control plane API, for dealing with generations (see docs/rfcs/025-generation-numbers.md)
@@ -63,7 +65,7 @@ impl ControlPlaneClient {
        let mut client = reqwest::ClientBuilder::new();

        if let Some(jwt) = &conf.control_plane_api_token {
-            let mut headers = reqwest::header::HeaderMap::new();
+            let mut headers = hyper::HeaderMap::new();
            headers.insert(
                "Authorization",
                format!("Bearer {}", jwt.get_contents()).parse().unwrap(),
--- a/pageserver/src/http/openapi_spec.yml
+++ b/pageserver/src/http/openapi_spec.yml
@@ -782,6 +782,9 @@ components:
      required:
        - mode
      properties:
+        tenant_id:
+          type: string
+          description: Not used, scheduled for removal.
        mode:
          type: string
          enum: ["AttachedSingle", "AttachedMulti", "AttachedStale", "Secondary", "Detached"]
--- a/pageserver/src/http/routes.rs
+++ b/pageserver/src/http/routes.rs
@@ -19,8 +19,6 @@ use pageserver_api::models::LocationConfigListResponse;
 use pageserver_api::models::ShardParameters;
 use pageserver_api::models::TenantDetails;
 use pageserver_api::models::TenantLocationConfigResponse;
-use pageserver_api::models::TenantScanRemoteStorageResponse;
-use pageserver_api::models::TenantScanRemoteStorageShard;
 use pageserver_api::models::TenantShardLocation;
 use pageserver_api::models::TenantShardSplitRequest;
 use pageserver_api::models::TenantShardSplitResponse;
@@ -31,7 +29,6 @@ use pageserver_api::models::{
 };
 use pageserver_api::shard::ShardCount;
 use pageserver_api::shard::TenantShardId;
-use remote_storage::DownloadError;
 use remote_storage::GenericRemoteStorage;
 use remote_storage::TimeTravelError;
 use tenant_size_model::{SizeResult, StorageModel};
@@ -57,9 +54,6 @@ use crate::tenant::mgr::{
 };
 use crate::tenant::mgr::{TenantSlot, UpsertLocationError};
 use crate::tenant::remote_timeline_client;
-use crate::tenant::remote_timeline_client::download_index_part;
-use crate::tenant::remote_timeline_client::list_remote_tenant_shards;
-use crate::tenant::remote_timeline_client::list_remote_timelines;
 use crate::tenant::secondary::SecondaryController;
 use crate::tenant::size::ModelInputs;
 use crate::tenant::storage_layer::LayerAccessStatsReset;
@@ -1918,14 +1912,12 @@ async fn timeline_collect_keyspace(
        let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
        let timeline = active_timeline_of_active_tenant(&state.tenant_manager, tenant_shard_id, timeline_id).await?;
        let at_lsn = at_lsn.unwrap_or_else(|| timeline.get_last_record_lsn());
-        let (dense_ks, sparse_ks) = timeline
+        let keys = timeline
            .collect_keyspace(at_lsn, &ctx)
            .await
            .map_err(|e| ApiError::InternalServerError(e.into()))?;

-        // This API is currently used by pagebench. Pagebench will iterate all keys within the keyspace.
-        // Therefore, we split dense/sparse keys in this API.
-        let res = pageserver_api::models::partitioning::Partitioning { keys: dense_ks, sparse_keys: sparse_ks, at_lsn };
+        let res = pageserver_api::models::partitioning::Partitioning { keys, at_lsn };

        json_response(StatusCode::OK, res)
    }
@@ -2043,79 +2035,6 @@ async fn secondary_upload_handler(
    json_response(StatusCode::OK, ())
 }

-async fn tenant_scan_remote_handler(
-    request: Request<Body>,
-    cancel: CancellationToken,
-) -> Result<Response<Body>, ApiError> {
-    let state = get_state(&request);
-    let tenant_id: TenantId = parse_request_param(&request, "tenant_id")?;
-
-    let Some(remote_storage) = state.remote_storage.as_ref() else {
-        return Err(ApiError::BadRequest(anyhow::anyhow!(
-            "Remote storage not configured"
-        )));
-    };
-
-    let mut response = TenantScanRemoteStorageResponse::default();
-
-    let (shards, _other_keys) =
-        list_remote_tenant_shards(remote_storage, tenant_id, cancel.clone())
-            .await
-            .map_err(|e| ApiError::InternalServerError(anyhow::anyhow!(e)))?;
-
-    for tenant_shard_id in shards {
-        let (timeline_ids, _other_keys) =
-            list_remote_timelines(remote_storage, tenant_shard_id, cancel.clone())
-                .await
-                .map_err(|e| ApiError::InternalServerError(anyhow::anyhow!(e)))?;
-
-        let mut generation = Generation::none();
-        for timeline_id in timeline_ids {
-            match download_index_part(
-                remote_storage,
-                &tenant_shard_id,
-                &timeline_id,
-                Generation::MAX,
-                &cancel,
-            )
-            .instrument(info_span!("download_index_part",
-                         tenant_id=%tenant_shard_id.tenant_id,
-                         shard_id=%tenant_shard_id.shard_slug(),
-                         %timeline_id))
-            .await
-            {
-                Ok((index_part, index_generation)) => {
-                    tracing::info!("Found timeline {tenant_shard_id}/{timeline_id} metadata (gen {index_generation:?}, {} layers, {} consistent LSN)",
-                        index_part.layer_metadata.len(), index_part.get_disk_consistent_lsn());
-                    generation = std::cmp::max(generation, index_generation);
-                }
-                Err(DownloadError::NotFound) => {
-                    // This is normal for tenants that were created with multiple shards: they have an unsharded path
-                    // containing the timeline's initdb tarball but no index.  Otherwise it is a bit strange.
-                    tracing::info!("Timeline path {tenant_shard_id}/{timeline_id} exists in remote storage but has no index, skipping");
-                    continue;
-                }
-                Err(e) => {
-                    return Err(ApiError::InternalServerError(anyhow::anyhow!(e)));
-                }
-            };
-        }
-
-        response.shards.push(TenantScanRemoteStorageShard {
-            tenant_shard_id,
-            generation: generation.into(),
-        });
-    }
-
-    if response.shards.is_empty() {
-        return Err(ApiError::NotFound(
-            anyhow::anyhow!("No shards found for tenant ID {tenant_id}").into(),
-        ));
-    }
-
-    json_response(StatusCode::OK, response)
-}
-
 async fn secondary_download_handler(
    request: Request<Body>,
    _cancel: CancellationToken,
@@ -2160,27 +2079,6 @@ async fn secondary_download_handler(
    json_response(status, progress)
 }

-async fn secondary_status_handler(
-    request: Request<Body>,
-    _cancel: CancellationToken,
-) -> Result<Response<Body>, ApiError> {
-    let state = get_state(&request);
-    let tenant_shard_id: TenantShardId = parse_request_param(&request, "tenant_shard_id")?;
-
-    let Some(secondary_tenant) = state
-        .tenant_manager
-        .get_secondary_tenant_shard(tenant_shard_id)
-    else {
-        return Err(ApiError::NotFound(
-            anyhow::anyhow!("Shard {} not found", tenant_shard_id).into(),
-        ));
-    };
-
-    let progress = secondary_tenant.progress.lock().unwrap().clone();
-
-    json_response(StatusCode::OK, progress)
-}
-
 async fn handler_404(_: Request<Body>) -> Result<Response<Body>, ApiError> {
    json_response(
        StatusCode::NOT_FOUND,
@@ -2533,18 +2431,12 @@ pub fn make_router(
        .post("/v1/tenant/:tenant_shard_id/heatmap_upload", |r| {
            api_handler(r, secondary_upload_handler)
        })
-        .get("/v1/tenant/:tenant_id/scan_remote_storage", |r| {
-            api_handler(r, tenant_scan_remote_handler)
-        })
        .put("/v1/disk_usage_eviction/run", |r| {
            api_handler(r, disk_usage_eviction_run)
        })
        .put("/v1/deletion_queue/flush", |r| {
            api_handler(r, deletion_queue_flush)
        })
-        .get("/v1/tenant/:tenant_shard_id/secondary/status", |r| {
-            api_handler(r, secondary_status_handler)
-        })
        .post("/v1/tenant/:tenant_shard_id/secondary/download", |r| {
            api_handler(r, secondary_download_handler)
        })
--- a/pageserver/src/metrics.rs
+++ b/pageserver/src/metrics.rs
@@ -51,9 +51,6 @@ pub(crate) enum StorageTimeOperation {
    #[strum(serialize = "gc")]
    Gc,

-    #[strum(serialize = "find gc cutoffs")]
-    FindGcCutoffs,
-
    #[strum(serialize = "create tenant")]
    CreateTenant,
 }
@@ -194,11 +191,6 @@ pub(crate) struct GetVectoredLatency {
    map: EnumMap<TaskKind, Option<Histogram>>,
 }

-#[allow(dead_code)]
-pub(crate) struct ScanLatency {
-    map: EnumMap<TaskKind, Option<Histogram>>,
-}
-
 impl GetVectoredLatency {
    // Only these task types perform vectored gets. Filter all other tasks out to reduce total
    // cardinality of the metric.
@@ -209,48 +201,6 @@ impl GetVectoredLatency {
    }
 }

-impl ScanLatency {
-    // Only these task types perform vectored gets. Filter all other tasks out to reduce total
-    // cardinality of the metric.
-    const TRACKED_TASK_KINDS: [TaskKind; 1] = [TaskKind::PageRequestHandler];
-
-    pub(crate) fn for_task_kind(&self, task_kind: TaskKind) -> Option<&Histogram> {
-        self.map[task_kind].as_ref()
-    }
-}
-
-pub(crate) struct ScanLatencyOngoingRecording<'a> {
-    parent: &'a Histogram,
-    start: std::time::Instant,
-}
-
-impl<'a> ScanLatencyOngoingRecording<'a> {
-    pub(crate) fn start_recording(parent: &'a Histogram) -> ScanLatencyOngoingRecording<'a> {
-        let start = Instant::now();
-        ScanLatencyOngoingRecording { parent, start }
-    }
-
-    pub(crate) fn observe(self, throttled: Option<Duration>) {
-        let elapsed = self.start.elapsed();
-        let ex_throttled = if let Some(throttled) = throttled {
-            elapsed.checked_sub(throttled)
-        } else {
-            Some(elapsed)
-        };
-        if let Some(ex_throttled) = ex_throttled {
-            self.parent.observe(ex_throttled.as_secs_f64());
-        } else {
-            use utils::rate_limit::RateLimit;
-            static LOGGED: Lazy<Mutex<RateLimit>> =
-                Lazy::new(|| Mutex::new(RateLimit::new(Duration::from_secs(10))));
-            let mut rate_limit = LOGGED.lock().unwrap();
-            rate_limit.call(|| {
-                warn!("error deducting time spent throttled; this message is logged at a global rate limit");
-            });
-        }
-    }
-}
-
 pub(crate) static GET_VECTORED_LATENCY: Lazy<GetVectoredLatency> = Lazy::new(|| {
    let inner = register_histogram_vec!(
        "pageserver_get_vectored_seconds",
@@ -274,29 +224,6 @@ pub(crate) static GET_VECTORED_LATENCY: Lazy<GetVectoredLatency> = Lazy::new(||
    }
 });

-pub(crate) static SCAN_LATENCY: Lazy<ScanLatency> = Lazy::new(|| {
-    let inner = register_histogram_vec!(
-        "pageserver_scan_seconds",
-        "Time spent in scan, excluding time spent in timeline_get_throttle.",
-        &["task_kind"],
-        CRITICAL_OP_BUCKETS.into(),
-    )
-    .expect("failed to define a metric");
-
-    ScanLatency {
-        map: EnumMap::from_array(std::array::from_fn(|task_kind_idx| {
-            let task_kind = <TaskKind as enum_map::Enum>::from_usize(task_kind_idx);
-
-            if ScanLatency::TRACKED_TASK_KINDS.contains(&task_kind) {
-                let task_kind = task_kind.into();
-                Some(inner.with_label_values(&[task_kind]))
-            } else {
-                None
-            }
-        })),
-    }
-});
-
 pub(crate) struct PageCacheMetricsForTaskKind {
    pub read_accesses_materialized_page: IntCounter,
    pub read_accesses_immutable: IntCounter,
@@ -1512,80 +1439,29 @@ static REMOTE_TIMELINE_CLIENT_BYTES_FINISHED_COUNTER: Lazy<IntCounterVec> = Lazy
 });

 pub(crate) struct TenantManagerMetrics {
-    tenant_slots_attached: UIntGauge,
-    tenant_slots_secondary: UIntGauge,
-    tenant_slots_inprogress: UIntGauge,
+    pub(crate) tenant_slots: UIntGauge,
    pub(crate) tenant_slot_writes: IntCounter,
    pub(crate) unexpected_errors: IntCounter,
 }

-impl TenantManagerMetrics {
-    /// Helpers for tracking slots.  Note that these do not track the lifetime of TenantSlot objects
-    /// exactly: they track the lifetime of the slots _in the tenant map_.
-    pub(crate) fn slot_inserted(&self, slot: &TenantSlot) {
-        match slot {
-            TenantSlot::Attached(_) => {
-                self.tenant_slots_attached.inc();
-            }
-            TenantSlot::Secondary(_) => {
-                self.tenant_slots_secondary.inc();
-            }
-            TenantSlot::InProgress(_) => {
-                self.tenant_slots_inprogress.inc();
-            }
-        }
-    }
-
-    pub(crate) fn slot_removed(&self, slot: &TenantSlot) {
-        match slot {
-            TenantSlot::Attached(_) => {
-                self.tenant_slots_attached.dec();
-            }
-            TenantSlot::Secondary(_) => {
-                self.tenant_slots_secondary.dec();
-            }
-            TenantSlot::InProgress(_) => {
-                self.tenant_slots_inprogress.dec();
-            }
-        }
-    }
-
-    #[cfg(all(debug_assertions, not(test)))]
-    pub(crate) fn slots_total(&self) -> u64 {
-        self.tenant_slots_attached.get()
-            + self.tenant_slots_secondary.get()
-            + self.tenant_slots_inprogress.get()
-    }
-}
-
 pub(crate) static TENANT_MANAGER: Lazy<TenantManagerMetrics> = Lazy::new(|| {
-    let tenant_slots = register_uint_gauge_vec!(
+    TenantManagerMetrics {
+    tenant_slots: register_uint_gauge!(
        "pageserver_tenant_manager_slots",
        "How many slots currently exist, including all attached, secondary and in-progress operations",
-        &["mode"]
    )
-    .expect("failed to define a metric");
-    TenantManagerMetrics {
-        tenant_slots_attached: tenant_slots
-            .get_metric_with_label_values(&["attached"])
-            .unwrap(),
-        tenant_slots_secondary: tenant_slots
-            .get_metric_with_label_values(&["secondary"])
-            .unwrap(),
-        tenant_slots_inprogress: tenant_slots
-            .get_metric_with_label_values(&["inprogress"])
-            .unwrap(),
-        tenant_slot_writes: register_int_counter!(
-            "pageserver_tenant_manager_slot_writes",
-            "Writes to a tenant slot, including all of create/attach/detach/delete"
-        )
-        .expect("failed to define a metric"),
-        unexpected_errors: register_int_counter!(
-            "pageserver_tenant_manager_unexpected_errors_total",
-            "Number of unexpected conditions encountered: nonzero value indicates a non-fatal bug."
-        )
-        .expect("failed to define a metric"),
-    }
+    .expect("failed to define a metric"),
+    tenant_slot_writes: register_int_counter!(
+        "pageserver_tenant_manager_slot_writes",
+        "Writes to a tenant slot, including all of create/attach/detach/delete"
+    )
+    .expect("failed to define a metric"),
+    unexpected_errors: register_int_counter!(
+        "pageserver_tenant_manager_unexpected_errors_total",
+        "Number of unexpected conditions encountered: nonzero value indicates a non-fatal bug."
+    )
+    .expect("failed to define a metric"),
+}
 });

 pub(crate) struct DeletionQueueMetrics {
@@ -2034,22 +1910,6 @@ impl StorageTimeMetricsTimer {
        self.metrics.timeline_count.inc();
        self.metrics.global_histogram.observe(duration);
    }
-
-    /// Turns this timer into a timer, which will always record -- usually this means recording
-    /// regardless an early `?` path was taken in a function.
-    pub(crate) fn record_on_drop(self) -> AlwaysRecordingStorageTimeMetricsTimer {
-        AlwaysRecordingStorageTimeMetricsTimer(Some(self))
-    }
-}
-
-pub(crate) struct AlwaysRecordingStorageTimeMetricsTimer(Option<StorageTimeMetricsTimer>);
-
-impl Drop for AlwaysRecordingStorageTimeMetricsTimer {
-    fn drop(&mut self) {
-        if let Some(inner) = self.0.take() {
-            inner.stop_and_record();
-        }
-    }
 }

 /// Timing facilities for an globally histogrammed metric, which is supported by per tenant and
@@ -2110,7 +1970,6 @@ pub(crate) struct TimelineMetrics {
    pub imitate_logical_size_histo: StorageTimeMetrics,
    pub load_layer_map_histo: StorageTimeMetrics,
    pub garbage_collect_histo: StorageTimeMetrics,
-    pub find_gc_cutoffs_histo: StorageTimeMetrics,
    pub last_record_gauge: IntGauge,
    resident_physical_size_gauge: UIntGauge,
    /// copy of LayeredTimeline.current_logical_size
@@ -2171,12 +2030,6 @@ impl TimelineMetrics {
            &shard_id,
            &timeline_id,
        );
-        let find_gc_cutoffs_histo = StorageTimeMetrics::new(
-            StorageTimeOperation::FindGcCutoffs,
-            &tenant_id,
-            &shard_id,
-            &timeline_id,
-        );
        let last_record_gauge = LAST_RECORD_LSN
            .get_metric_with_label_values(&[&tenant_id, &shard_id, &timeline_id])
            .unwrap();
@@ -2219,7 +2072,6 @@ impl TimelineMetrics {
            logical_size_histo,
            imitate_logical_size_histo,
            garbage_collect_histo,
-            find_gc_cutoffs_histo,
            load_layer_map_histo,
            last_record_gauge,
            resident_physical_size_gauge,
@@ -2326,7 +2178,6 @@ use std::time::{Duration, Instant};

 use crate::context::{PageContentKind, RequestContext};
 use crate::task_mgr::TaskKind;
-use crate::tenant::mgr::TenantSlot;

 /// Maintain a per timeline gauge in addition to the global gauge.
 struct PerTimelineRemotePhysicalSizeGauge {
--- a/pageserver/src/page_service.rs
+++ b/pageserver/src/page_service.rs
@@ -1,5 +1,13 @@
+//
 //! The Page Service listens for client connections and serves their GetPage@LSN
 //! requests.
+//
+//   It is possible to connect here using usual psql/pgbench/libpq. Following
+// commands are supported now:
+//     *status* -- show actual info about this pageserver,
+//     *pagestream* -- enter mode where smgr and pageserver talk with their
+//  custom protocol.
+//

 use anyhow::Context;
 use async_compression::tokio::write::GzipEncoder;
@@ -15,7 +23,7 @@ use pageserver_api::models::{
    PagestreamErrorResponse, PagestreamExistsRequest, PagestreamExistsResponse,
    PagestreamFeMessage, PagestreamGetPageRequest, PagestreamGetPageResponse,
    PagestreamGetSlruSegmentRequest, PagestreamGetSlruSegmentResponse, PagestreamNblocksRequest,
-    PagestreamNblocksResponse, PagestreamProtocolVersion,
+    PagestreamNblocksResponse,
 };
 use pageserver_api::shard::ShardIndex;
 use pageserver_api::shard::ShardNumber;
@@ -48,7 +56,6 @@ use utils::{

 use crate::auth::check_permission;
 use crate::basebackup;
-use crate::basebackup::BasebackupError;
 use crate::config::PageServerConf;
 use crate::context::{DownloadBehavior, RequestContext};
 use crate::import_datadir::import_wal_from_tar;
@@ -544,7 +551,6 @@ impl PageServerHandler {
        pgb: &mut PostgresBackend<IO>,
        tenant_id: TenantId,
        timeline_id: TimelineId,
-        protocol_version: PagestreamProtocolVersion,
        ctx: RequestContext,
    ) -> Result<(), QueryError>
    where
@@ -607,15 +613,14 @@ impl PageServerHandler {
                t.trace(&copy_data_bytes)
            }

-            let neon_fe_msg =
-                PagestreamFeMessage::parse(&mut copy_data_bytes.reader(), protocol_version)?;
+            let neon_fe_msg = PagestreamFeMessage::parse(&mut copy_data_bytes.reader())?;

            // TODO: We could create a new per-request context here, with unique ID.
            // Currently we use the same per-timeline context for all requests

            let (response, span) = match neon_fe_msg {
                PagestreamFeMessage::Exists(req) => {
-                    let span = tracing::info_span!("handle_get_rel_exists_request", rel = %req.rel, req_lsn = %req.request_lsn);
+                    let span = tracing::info_span!("handle_get_rel_exists_request", rel = %req.rel, req_lsn = %req.lsn);
                    (
                        self.handle_get_rel_exists_request(tenant_id, timeline_id, &req, &ctx)
                            .instrument(span.clone())
@@ -624,7 +629,7 @@ impl PageServerHandler {
                    )
                }
                PagestreamFeMessage::Nblocks(req) => {
-                    let span = tracing::info_span!("handle_get_nblocks_request", rel = %req.rel, req_lsn = %req.request_lsn);
+                    let span = tracing::info_span!("handle_get_nblocks_request", rel = %req.rel, req_lsn = %req.lsn);
                    (
                        self.handle_get_nblocks_request(tenant_id, timeline_id, &req, &ctx)
                            .instrument(span.clone())
@@ -634,7 +639,7 @@ impl PageServerHandler {
                }
                PagestreamFeMessage::GetPage(req) => {
                    // shard_id is filled in by the handler
-                    let span = tracing::info_span!("handle_get_page_at_lsn_request", rel = %req.rel, blkno = %req.blkno, req_lsn = %req.request_lsn);
+                    let span = tracing::info_span!("handle_get_page_at_lsn_request", rel = %req.rel, blkno = %req.blkno, req_lsn = %req.lsn);
                    (
                        self.handle_get_page_at_lsn_request(tenant_id, timeline_id, &req, &ctx)
                            .instrument(span.clone())
@@ -643,7 +648,7 @@ impl PageServerHandler {
                    )
                }
                PagestreamFeMessage::DbSize(req) => {
-                    let span = tracing::info_span!("handle_db_size_request", dbnode = %req.dbnode, req_lsn = %req.request_lsn);
+                    let span = tracing::info_span!("handle_db_size_request", dbnode = %req.dbnode, req_lsn = %req.lsn);
                    (
                        self.handle_db_size_request(tenant_id, timeline_id, &req, &ctx)
                            .instrument(span.clone())
@@ -652,7 +657,7 @@ impl PageServerHandler {
                    )
                }
                PagestreamFeMessage::GetSlruSegment(req) => {
-                    let span = tracing::info_span!("handle_get_slru_segment_request", kind = %req.kind, segno = %req.segno, req_lsn = %req.request_lsn);
+                    let span = tracing::info_span!("handle_get_slru_segment_request", kind = %req.kind, segno = %req.segno, req_lsn = %req.lsn);
                    (
                        self.handle_get_slru_segment_request(tenant_id, timeline_id, &req, &ctx)
                            .instrument(span.clone())
@@ -833,80 +838,83 @@ impl PageServerHandler {
    /// Helper function to handle the LSN from client request.
    ///
    /// Each GetPage (and Exists and Nblocks) request includes information about
-    /// which version of the page is being requested. The primary compute node
-    /// will always request the latest page version, by setting 'request_lsn' to
-    /// the last inserted or flushed WAL position, while a standby will request
-    /// a version at the LSN that it's currently caught up to.
+    /// which version of the page is being requested. The client can request the
+    /// latest version of the page, or the version that's valid at a particular
+    /// LSN. The primary compute node will always request the latest page
+    /// version, while a standby will request a version at the LSN that it's
+    /// currently caught up to.
    ///
    /// In either case, if the page server hasn't received the WAL up to the
    /// requested LSN yet, we will wait for it to arrive. The return value is
    /// the LSN that should be used to look up the page versions.
-    ///
-    /// In addition to the request LSN, each request carries another LSN,
-    /// 'not_modified_since', which is a hint to the pageserver that the client
-    /// knows that the page has not been modified between 'not_modified_since'
-    /// and the request LSN. This allows skipping the wait, as long as the WAL
-    /// up to 'not_modified_since' has arrived. If the client doesn't have any
-    /// information about when the page was modified, it will use
-    /// not_modified_since == lsn. If the client lies and sends a too low
-    /// not_modified_hint such that there are in fact later page versions, the
-    /// behavior is undefined: the pageserver may return any of the page versions
-    /// or an error.
    async fn wait_or_get_last_lsn(
        timeline: &Timeline,
-        request_lsn: Lsn,
-        not_modified_since: Lsn,
+        mut lsn: Lsn,
+        latest: bool,
        latest_gc_cutoff_lsn: &RcuReadGuard<Lsn>,
        ctx: &RequestContext,
    ) -> Result<Lsn, PageStreamError> {
-        let last_record_lsn = timeline.get_last_record_lsn();
+        if latest {
+            // Latest page version was requested. If LSN is given, it is a hint
+            // to the page server that there have been no modifications to the
+            // page after that LSN. If we haven't received WAL up to that point,
+            // wait until it arrives.
+            let last_record_lsn = timeline.get_last_record_lsn();

-        // Sanity check the request
-        if request_lsn < not_modified_since {
-            return Err(PageStreamError::BadRequest(
-                format!(
-                    "invalid request with request LSN {} and not_modified_since {}",
-                    request_lsn, not_modified_since,
-                )
-                .into(),
-            ));
-        }
-
-        if request_lsn < **latest_gc_cutoff_lsn {
-            // Check explicitly for INVALID just to get a less scary error message if the
-            // request is obviously bogus
-            return Err(if request_lsn == Lsn::INVALID {
-                PageStreamError::BadRequest("invalid LSN(0) in request".into())
+            // Note: this covers the special case that lsn == Lsn(0). That
+            // special case means "return the latest version whatever it is",
+            // and it's used for bootstrapping purposes, when the page server is
+            // connected directly to the compute node. That is needed because
+            // when you connect to the compute node, to receive the WAL, the
+            // walsender process will do a look up in the pg_authid catalog
+            // table for authentication. That poses a deadlock problem: the
+            // catalog table lookup will send a GetPage request, but the GetPage
+            // request will block in the page server because the recent WAL
+            // hasn't been received yet, and it cannot be received until the
+            // walsender completes the authentication and starts streaming the
+            // WAL.
+            if lsn <= last_record_lsn {
+                // It might be better to use max(lsn, latest_gc_cutoff_lsn) instead
+                // last_record_lsn. That would give the same result, since we know
+                // that there haven't been modifications since 'lsn'. Using an older
+                // LSN might be faster, because that could allow skipping recent
+                // layers when finding the page.
+                lsn = last_record_lsn;
            } else {
-                PageStreamError::BadRequest(format!(
-                        "tried to request a page version that was garbage collected. requested at {} gc cutoff {}",
-                        request_lsn, **latest_gc_cutoff_lsn
-                    ).into())
-            });
-        }
-
-        // Wait for WAL up to 'not_modified_since' to arrive, if necessary
-        if not_modified_since > last_record_lsn {
+                timeline
+                    .wait_lsn(
+                        lsn,
+                        crate::tenant::timeline::WaitLsnWaiter::PageService,
+                        ctx,
+                    )
+                    .await?;
+                // Since we waited for 'lsn' to arrive, that is now the last
+                // record LSN. (Or close enough for our purposes; the
+                // last-record LSN can advance immediately after we return
+                // anyway)
+            }
+        } else {
+            if lsn == Lsn(0) {
+                return Err(PageStreamError::BadRequest(
+                    "invalid LSN(0) in request".into(),
+                ));
+            }
            timeline
                .wait_lsn(
-                    not_modified_since,
+                    lsn,
                    crate::tenant::timeline::WaitLsnWaiter::PageService,
                    ctx,
                )
                .await?;
-            // Since we waited for 'not_modified_since' to arrive, that is now the last
-            // record LSN. (Or close enough for our purposes; the last-record LSN can
-            // advance immediately after we return anyway)
-            Ok(not_modified_since)
-        } else {
-            // It might be better to use max(not_modified_since, latest_gc_cutoff_lsn)
-            // here instead. That would give the same result, since we know that there
-            // haven't been any modifications since 'not_modified_since'. Using an older
-            // LSN might be faster, because that could allow skipping recent layers when
-            // finding the page. However, we have historically used 'last_record_lsn', so
-            // stick to that for now.
-            Ok(std::cmp::min(last_record_lsn, request_lsn))
        }
+
+        if lsn < **latest_gc_cutoff_lsn {
+            return Err(PageStreamError::BadRequest(format!(
+                "tried to request a page version that was garbage collected. requested at {} gc cutoff {}",
+                lsn, **latest_gc_cutoff_lsn
+            ).into()));
+        }
+        Ok(lsn)
    }

    #[instrument(skip_all, fields(shard_id))]
@@ -923,17 +931,12 @@ impl PageServerHandler {
            .start_timer(metrics::SmgrQueryType::GetRelExists, ctx);

        let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(
-            timeline,
-            req.request_lsn,
-            req.not_modified_since,
-            &latest_gc_cutoff_lsn,
-            ctx,
-        )
-        .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;

        let exists = timeline
-            .get_rel_exists(req.rel, Version::Lsn(lsn), ctx)
+            .get_rel_exists(req.rel, Version::Lsn(lsn), req.latest, ctx)
            .await?;

        Ok(PagestreamBeMessage::Exists(PagestreamExistsResponse {
@@ -956,17 +959,12 @@ impl PageServerHandler {
            .start_timer(metrics::SmgrQueryType::GetRelSize, ctx);

        let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(
-            timeline,
-            req.request_lsn,
-            req.not_modified_since,
-            &latest_gc_cutoff_lsn,
-            ctx,
-        )
-        .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;

        let n_blocks = timeline
-            .get_rel_size(req.rel, Version::Lsn(lsn), ctx)
+            .get_rel_size(req.rel, Version::Lsn(lsn), req.latest, ctx)
            .await?;

        Ok(PagestreamBeMessage::Nblocks(PagestreamNblocksResponse {
@@ -989,17 +987,18 @@ impl PageServerHandler {
            .start_timer(metrics::SmgrQueryType::GetDbSize, ctx);

        let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(
-            timeline,
-            req.request_lsn,
-            req.not_modified_since,
-            &latest_gc_cutoff_lsn,
-            ctx,
-        )
-        .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;

        let total_blocks = timeline
-            .get_db_size(DEFAULTTABLESPACE_OID, req.dbnode, Version::Lsn(lsn), ctx)
+            .get_db_size(
+                DEFAULTTABLESPACE_OID,
+                req.dbnode,
+                Version::Lsn(lsn),
+                req.latest,
+                ctx,
+            )
            .await?;
        let db_size = total_blocks as i64 * BLCKSZ as i64;

@@ -1166,17 +1165,12 @@ impl PageServerHandler {
            .start_timer(metrics::SmgrQueryType::GetPageAtLsn, ctx);

        let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(
-            timeline,
-            req.request_lsn,
-            req.not_modified_since,
-            &latest_gc_cutoff_lsn,
-            ctx,
-        )
-        .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;

        let page = timeline
-            .get_rel_page_at_lsn(req.rel, req.blkno, Version::Lsn(lsn), ctx)
+            .get_rel_page_at_lsn(req.rel, req.blkno, Version::Lsn(lsn), req.latest, ctx)
            .await?;

        Ok(PagestreamBeMessage::GetPage(PagestreamGetPageResponse {
@@ -1199,14 +1193,9 @@ impl PageServerHandler {
            .start_timer(metrics::SmgrQueryType::GetSlruSegment, ctx);

        let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(
-            timeline,
-            req.request_lsn,
-            req.not_modified_since,
-            &latest_gc_cutoff_lsn,
-            ctx,
-        )
-        .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;

        let kind = SlruKind::from_repr(req.kind)
            .ok_or(PageStreamError::BadRequest("invalid SLRU kind".into()))?;
@@ -1237,13 +1226,6 @@ impl PageServerHandler {
    where
        IO: AsyncRead + AsyncWrite + Send + Sync + Unpin,
    {
-        fn map_basebackup_error(err: BasebackupError) -> QueryError {
-            match err {
-                BasebackupError::Client(e) => QueryError::Disconnected(ConnectionError::Io(e)),
-                BasebackupError::Server(e) => QueryError::Other(e),
-            }
-        }
-
        let started = std::time::Instant::now();

        // check that the timeline exists
@@ -1269,8 +1251,7 @@ impl PageServerHandler {
        let lsn_awaited_after = started.elapsed();

        // switch client to COPYOUT
-        pgb.write_message_noflush(&BeMessage::CopyOutResponse)
-            .map_err(QueryError::Disconnected)?;
+        pgb.write_message_noflush(&BeMessage::CopyOutResponse)?;
        self.flush_cancellable(pgb, &timeline.cancel).await?;

        // Send a tarball of the latest layer on the timeline. Compress if not
@@ -1285,8 +1266,7 @@ impl PageServerHandler {
                full_backup,
                ctx,
            )
-            .await
-            .map_err(map_basebackup_error)?;
+            .await?;
        } else {
            let mut writer = pgb.copyout_writer();
            if gzip {
@@ -1307,13 +1287,9 @@ impl PageServerHandler {
                    full_backup,
                    ctx,
                )
-                .await
-                .map_err(map_basebackup_error)?;
+                .await?;
                // shutdown the encoder to ensure the gzip footer is written
-                encoder
-                    .shutdown()
-                    .await
-                    .map_err(|e| QueryError::Disconnected(ConnectionError::Io(e)))?;
+                encoder.shutdown().await?;
            } else {
                basebackup::send_basebackup_tarball(
                    &mut writer,
@@ -1323,13 +1299,11 @@ impl PageServerHandler {
                    full_backup,
                    ctx,
                )
-                .await
-                .map_err(map_basebackup_error)?;
+                .await?;
            }
        }

-        pgb.write_message_noflush(&BeMessage::CopyDone)
-            .map_err(QueryError::Disconnected)?;
+        pgb.write_message_noflush(&BeMessage::CopyDone)?;
        self.flush_cancellable(pgb, &timeline.cancel).await?;

        let basebackup_after = started
@@ -1439,34 +1413,7 @@ where

        let ctx = self.connection_ctx.attached_child();
        debug!("process query {query_string:?}");
-        if query_string.starts_with("pagestream_v2 ") {
-            let (_, params_raw) = query_string.split_at("pagestream_v2 ".len());
-            let params = params_raw.split(' ').collect::<Vec<_>>();
-            if params.len() != 2 {
-                return Err(QueryError::Other(anyhow::anyhow!(
-                    "invalid param number for pagestream command"
-                )));
-            }
-            let tenant_id = TenantId::from_str(params[0])
-                .with_context(|| format!("Failed to parse tenant id from {}", params[0]))?;
-            let timeline_id = TimelineId::from_str(params[1])
-                .with_context(|| format!("Failed to parse timeline id from {}", params[1]))?;
-
-            tracing::Span::current()
-                .record("tenant_id", field::display(tenant_id))
-                .record("timeline_id", field::display(timeline_id));
-
-            self.check_permission(Some(tenant_id))?;
-
-            self.handle_pagerequests(
-                pgb,
-                tenant_id,
-                timeline_id,
-                PagestreamProtocolVersion::V2,
-                ctx,
-            )
-            .await?;
-        } else if query_string.starts_with("pagestream ") {
+        if query_string.starts_with("pagestream ") {
            let (_, params_raw) = query_string.split_at("pagestream ".len());
            let params = params_raw.split(' ').collect::<Vec<_>>();
            if params.len() != 2 {
@@ -1485,14 +1432,8 @@ where

            self.check_permission(Some(tenant_id))?;

-            self.handle_pagerequests(
-                pgb,
-                tenant_id,
-                timeline_id,
-                PagestreamProtocolVersion::V1,
-                ctx,
-            )
-            .await?;
+            self.handle_pagerequests(pgb, tenant_id, timeline_id, ctx)
+                .await?;
        } else if query_string.starts_with("basebackup ") {
            let (_, params_raw) = query_string.split_at("basebackup ".len());
            let params = params_raw.split_whitespace().collect::<Vec<_>>();
--- a/pageserver/src/pgdatadir_mapping.rs
+++ b/pageserver/src/pgdatadir_mapping.rs
@@ -23,7 +23,6 @@ use pageserver_api::key::{
    slru_segment_key_range, slru_segment_size_to_key, twophase_file_key, twophase_key_range,
    AUX_FILES_KEY, CHECKPOINT_KEY, CONTROLFILE_KEY, DBDIR_KEY, TWOPHASEDIR_KEY,
 };
-use pageserver_api::keyspace::SparseKeySpace;
 use pageserver_api::reltag::{BlockNumber, RelTag, SlruKind};
 use postgres_ffi::relfile_utils::{FSM_FORKNUM, VISIBILITYMAP_FORKNUM};
 use postgres_ffi::BLCKSZ;
@@ -177,6 +176,7 @@ impl Timeline {
        tag: RelTag,
        blknum: BlockNumber,
        version: Version<'_>,
+        latest: bool,
        ctx: &RequestContext,
    ) -> Result<Bytes, PageReconstructError> {
        if tag.relnode == 0 {
@@ -185,7 +185,7 @@ impl Timeline {
            ));
        }

-        let nblocks = self.get_rel_size(tag, version, ctx).await?;
+        let nblocks = self.get_rel_size(tag, version, latest, ctx).await?;
        if blknum >= nblocks {
            debug!(
                "read beyond EOF at {} blk {} at {}, size is {}: returning all-zeros page",
@@ -207,6 +207,7 @@ impl Timeline {
        spcnode: Oid,
        dbnode: Oid,
        version: Version<'_>,
+        latest: bool,
        ctx: &RequestContext,
    ) -> Result<usize, PageReconstructError> {
        let mut total_blocks = 0;
@@ -214,7 +215,7 @@ impl Timeline {
        let rels = self.list_rels(spcnode, dbnode, version, ctx).await?;

        for rel in rels {
-            let n_blocks = self.get_rel_size(rel, version, ctx).await?;
+            let n_blocks = self.get_rel_size(rel, version, latest, ctx).await?;
            total_blocks += n_blocks as usize;
        }
        Ok(total_blocks)
@@ -225,6 +226,7 @@ impl Timeline {
        &self,
        tag: RelTag,
        version: Version<'_>,
+        latest: bool,
        ctx: &RequestContext,
    ) -> Result<BlockNumber, PageReconstructError> {
        if tag.relnode == 0 {
@@ -238,7 +240,7 @@ impl Timeline {
        }

        if (tag.forknum == FSM_FORKNUM || tag.forknum == VISIBILITYMAP_FORKNUM)
-            && !self.get_rel_exists(tag, version, ctx).await?
+            && !self.get_rel_exists(tag, version, latest, ctx).await?
        {
            // FIXME: Postgres sometimes calls smgrcreate() to create
            // FSM, and smgrnblocks() on it immediately afterwards,
@@ -261,6 +263,7 @@ impl Timeline {
        &self,
        tag: RelTag,
        version: Version<'_>,
+        _latest: bool,
        ctx: &RequestContext,
    ) -> Result<bool, PageReconstructError> {
        if tag.relnode == 0 {
@@ -279,7 +282,7 @@ impl Timeline {

        match RelDirectory::des(&buf).context("deserialization failure") {
            Ok(dir) => {
-                let exists = dir.rels.contains(&(tag.relnode, tag.forknum));
+                let exists = dir.rels.get(&(tag.relnode, tag.forknum)).is_some();
                Ok(exists)
            }
            Err(e) => Err(PageReconstructError::from(e)),
@@ -379,7 +382,7 @@ impl Timeline {

        match SlruSegmentDirectory::des(&buf).context("deserialization failure") {
            Ok(dir) => {
-                let exists = dir.segments.contains(&segno);
+                let exists = dir.segments.get(&segno).is_some();
                Ok(exists)
            }
            Err(e) => Err(PageReconstructError::from(e)),
@@ -446,6 +449,11 @@ impl Timeline {
        // include physical changes from later commits that will be marked
        // as aborted, and will need to be vacuumed away.
        let commit_lsn = Lsn((low - 1) * 8);
+        // This maxing operation is for the edge case that the search above did
+        // set found_smaller to true but it never increased the lsn. Then, low
+        // is still the old min_lsn the subtraction above could possibly give a value
+        // below the anchestor_lsn.
+        let commit_lsn = commit_lsn.max(min_lsn);
        match (found_smaller, found_larger) {
            (false, false) => {
                // This can happen if no commit records have been processed yet, e.g.
@@ -456,12 +464,6 @@ impl Timeline {
                // Didn't find any commit timestamps smaller than the request
                Ok(LsnForTimestamp::Past(min_lsn))
            }
-            (true, _) if commit_lsn < min_lsn => {
-                // the search above did set found_smaller to true but it never increased the lsn.
-                // Then, low is still the old min_lsn, and the subtraction above gave a value
-                // below the min_lsn. We should never do that.
-                Ok(LsnForTimestamp::Past(min_lsn))
-            }
            (true, false) => {
                // Only found commits with timestamps smaller than the request.
                // It's still a valid case for branch creation, return it.
@@ -731,13 +733,11 @@ impl Timeline {
    /// Get a KeySpace that covers all the Keys that are in use at the given LSN.
    /// Anything that's not listed maybe removed from the underlying storage (from
    /// that LSN forwards).
-    ///
-    /// The return value is (dense keyspace, sparse keyspace).
    pub(crate) async fn collect_keyspace(
        &self,
        lsn: Lsn,
        ctx: &RequestContext,
-    ) -> Result<(KeySpace, SparseKeySpace), CollectKeySpaceError> {
+    ) -> Result<KeySpace, CollectKeySpaceError> {
        // Iterate through key ranges, greedily packing them into partitions
        let mut result = KeySpaceAccum::new();

@@ -809,12 +809,7 @@ impl Timeline {
        if self.get(AUX_FILES_KEY, lsn, ctx).await.is_ok() {
            result.add_key(AUX_FILES_KEY);
        }
-
-        Ok((
-            result.to_keyspace(),
-            /* AUX sparse key space */
-            SparseKeySpace(KeySpace::single(Key::metadata_aux_key_range())),
-        ))
+        Ok(result.to_keyspace())
    }

    /// Get cached size of relation if it not updated after specified LSN
@@ -1100,7 +1095,7 @@ impl<'a> DatadirModification<'a> {
    ) -> anyhow::Result<()> {
        let total_blocks = self
            .tline
-            .get_db_size(spcnode, dbnode, Version::Modified(self), ctx)
+            .get_db_size(spcnode, dbnode, Version::Modified(self), true, ctx)
            .await?;

        // Remove entry from dbdir
@@ -1143,22 +1138,21 @@ impl<'a> DatadirModification<'a> {
        let mut dbdir = DbDirectory::des(&self.get(DBDIR_KEY, ctx).await.context("read db")?)
            .context("deserialize db")?;
        let rel_dir_key = rel_dir_to_key(rel.spcnode, rel.dbnode);
-        let mut rel_dir =
-            if let hash_map::Entry::Vacant(e) = dbdir.dbdirs.entry((rel.spcnode, rel.dbnode)) {
-                // Didn't exist. Update dbdir
-                e.insert(false);
-                let buf = DbDirectory::ser(&dbdir).context("serialize db")?;
-                self.pending_directory_entries
-                    .push((DirectoryKind::Db, dbdir.dbdirs.len()));
-                self.put(DBDIR_KEY, Value::Image(buf.into()));
+        let mut rel_dir = if dbdir.dbdirs.get(&(rel.spcnode, rel.dbnode)).is_none() {
+            // Didn't exist. Update dbdir
+            dbdir.dbdirs.insert((rel.spcnode, rel.dbnode), false);
+            let buf = DbDirectory::ser(&dbdir).context("serialize db")?;
+            self.pending_directory_entries
+                .push((DirectoryKind::Db, dbdir.dbdirs.len()));
+            self.put(DBDIR_KEY, Value::Image(buf.into()));

-                // and create the RelDirectory
-                RelDirectory::default()
-            } else {
-                // reldir already exists, fetch it
-                RelDirectory::des(&self.get(rel_dir_key, ctx).await.context("read db")?)
-                    .context("deserialize db")?
-            };
+            // and create the RelDirectory
+            RelDirectory::default()
+        } else {
+            // reldir already exists, fetch it
+            RelDirectory::des(&self.get(rel_dir_key, ctx).await.context("read db")?)
+                .context("deserialize db")?
+        };

        // Add the new relation to the rel directory entry, and write it back
        if !rel_dir.rels.insert((rel.relnode, rel.forknum)) {
@@ -1200,7 +1194,7 @@ impl<'a> DatadirModification<'a> {
        anyhow::ensure!(rel.relnode != 0, RelationError::InvalidRelnode);
        if self
            .tline
-            .get_rel_exists(rel, Version::Modified(self), ctx)
+            .get_rel_exists(rel, Version::Modified(self), true, ctx)
            .await?
        {
            let size_key = rel_size_to_key(rel);
--- a/pageserver/src/task_mgr.rs
+++ b/pageserver/src/task_mgr.rs
@@ -319,9 +319,6 @@ pub enum TaskKind {
    // Eviction. One per timeline.
    Eviction,

-    // Ingest housekeeping (flushing ephemeral layers on time threshold or disk pressure)
-    IngestHousekeeping,
-
    /// See [`crate::disk_usage_eviction_task`].
    DiskUsageEviction,

@@ -364,10 +361,6 @@ pub enum TaskKind {

    DebugTool,

-    EphemeralFilePreWarmPageCache,
-
-    LayerDownload,
-
    #[cfg(test)]
    UnitTest,
 }
--- a/pageserver/src/tenant.rs
+++ b/pageserver/src/tenant.rs
@@ -64,7 +64,6 @@ use self::timeline::uninit::UninitializedTimeline;
 use self::timeline::EvictionTaskTenantState;
 use self::timeline::TimelineResources;
 use self::timeline::WaitLsnError;
-use self::timeline::{GcCutoffs, GcInfo};
 use crate::config::PageServerConf;
 use crate::context::{DownloadBehavior, RequestContext};
 use crate::deletion_queue::DeletionQueueClient;
@@ -87,6 +86,7 @@ use crate::tenant::remote_timeline_client::INITDB_PATH;
 use crate::tenant::storage_layer::DeltaLayer;
 use crate::tenant::storage_layer::ImageLayer;
 use crate::InitializationOrder;
+use std::cmp::min;
 use std::collections::hash_map::Entry;
 use std::collections::BTreeSet;
 use std::collections::HashMap;
@@ -888,7 +888,7 @@ impl Tenant {

    #[instrument(skip_all)]
    pub(crate) async fn preload(
-        self: &Arc<Self>,
+        self: &Arc<Tenant>,
        remote_storage: &GenericRemoteStorage,
        cancel: CancellationToken,
    ) -> anyhow::Result<TenantPreload> {
@@ -918,13 +918,9 @@ impl Tenant {

        Ok(TenantPreload {
            deleting,
-            timelines: Self::load_timeline_metadata(
-                self,
-                remote_timeline_ids,
-                remote_storage,
-                cancel,
-            )
-            .await?,
+            timelines: self
+                .load_timeline_metadata(remote_timeline_ids, remote_storage, cancel)
+                .await?,
        })
    }

@@ -1676,34 +1672,6 @@ impl Tenant {
        Ok(())
    }

-    // Call through to all timelines to freeze ephemeral layers if needed.  Usually
-    // this happens during ingest: this background housekeeping is for freezing layers
-    // that are open but haven't been written to for some time.
-    async fn ingest_housekeeping(&self) {
-        // Scan through the hashmap and collect a list of all the timelines,
-        // while holding the lock. Then drop the lock and actually perform the
-        // compactions.  We don't want to block everything else while the
-        // compaction runs.
-        let timelines = {
-            self.timelines
-                .lock()
-                .unwrap()
-                .values()
-                .filter_map(|timeline| {
-                    if timeline.is_active() {
-                        Some(timeline.clone())
-                    } else {
-                        None
-                    }
-                })
-                .collect::<Vec<_>>()
-        };
-
-        for timeline in &timelines {
-            timeline.maybe_freeze_ephemeral_layer().await;
-        }
-    }
-
    pub fn current_state(&self) -> TenantState {
        self.state.borrow().clone()
    }
@@ -2840,48 +2808,7 @@ impl Tenant {
        cancel: &CancellationToken,
        ctx: &RequestContext,
    ) -> anyhow::Result<Vec<Arc<Timeline>>> {
-        // before taking the gc_cs lock, do the heavier weight finding of gc_cutoff points for
-        // currently visible timelines.
-        let timelines = self
-            .timelines
-            .lock()
-            .unwrap()
-            .values()
-            .filter(|tl| match target_timeline_id.as_ref() {
-                Some(target) => &tl.timeline_id == target,
-                None => true,
-            })
-            .cloned()
-            .collect::<Vec<_>>();
-
-        let mut gc_cutoffs: HashMap<TimelineId, GcCutoffs> =
-            HashMap::with_capacity(timelines.len());
-
-        for timeline in timelines.iter() {
-            let cutoff = timeline
-                .get_last_record_lsn()
-                .checked_sub(horizon)
-                .unwrap_or(Lsn(0));
-
-            let res = timeline.find_gc_cutoffs(cutoff, pitr, cancel, ctx).await;
-
-            match res {
-                Ok(cutoffs) => {
-                    let old = gc_cutoffs.insert(timeline.timeline_id, cutoffs);
-                    assert!(old.is_none());
-                }
-                Err(e) => {
-                    tracing::warn!(timeline_id = %timeline.timeline_id, "ignoring failure to find gc cutoffs: {e:#}");
-                }
-            }
-        }
-
-        if !self.is_active() {
-            anyhow::bail!("shutting down");
-        }
-
-        // grab mutex to prevent new timelines from being created here; avoid doing long operations
-        // because that will stall branch creation.
+        // grab mutex to prevent new timelines from being created here.
        let gc_cs = self.gc_cs.lock().await;

        // Scan all timelines. For each timeline, remember the timeline ID and
@@ -2943,6 +2870,11 @@ impl Tenant {
                }
            }

+            let cutoff = timeline
+                .get_last_record_lsn()
+                .checked_sub(horizon)
+                .unwrap_or(Lsn(0));
+
            let branchpoints: Vec<Lsn> = all_branchpoints
                .range((
                    Included((timeline_id, Lsn(0))),
@@ -2950,27 +2882,9 @@ impl Tenant {
                ))
                .map(|&x| x.1)
                .collect();
-
-            {
-                let mut target = timeline.gc_info.write().unwrap();
-
-                match gc_cutoffs.remove(&timeline_id) {
-                    Some(cutoffs) => {
-                        *target = GcInfo {
-                            retain_lsns: branchpoints,
-                            cutoffs,
-                        };
-                    }
-                    None => {
-                        // reasons for this being unavailable:
-                        // - this timeline was created while we were finding cutoffs
-                        // - lsn for timestamp search fails for this timeline repeatedly
-                        //
-                        // in both cases, refreshing the branchpoints is correct.
-                        target.retain_lsns = branchpoints;
-                    }
-                };
-            }
+            timeline
+                .update_gc_info(branchpoints, cutoff, pitr, cancel, ctx)
+                .await?;

            gc_timelines.push(timeline);
        }
@@ -3059,7 +2973,7 @@ impl Tenant {
        // and then the planned GC cutoff
        {
            let gc_info = src_timeline.gc_info.read().unwrap();
-            let cutoff = gc_info.min_cutoff();
+            let cutoff = min(gc_info.pitr_cutoff, gc_info.horizon_cutoff);
            if start_lsn < cutoff {
                return Err(CreateTimelineError::AncestorLsn(anyhow::anyhow!(
                    "invalid branch start lsn: less than planned GC cutoff {cutoff}"
@@ -3488,11 +3402,7 @@ impl Tenant {
        // is in progress (which is not a common case).
        //
        // See more for on the issue #2748 condenced out of the initial PR review.
-        let mut shared_cache = tokio::select! {
-            locked = self.cached_logical_sizes.lock() => locked,
-            _ = cancel.cancelled() => anyhow::bail!("cancelled"),
-            _ = self.cancel.cancelled() => anyhow::bail!("tenant is shutting down"),
-        };
+        let mut shared_cache = self.cached_logical_sizes.lock().await;

        size::gather_inputs(
            self,
@@ -3754,7 +3664,6 @@ pub(crate) mod harness {
                image_layer_creation_check_threshold: Some(
                    tenant_conf.image_layer_creation_check_threshold,
                ),
-                switch_to_aux_file_v2: Some(tenant_conf.switch_to_aux_file_v2),
            }
        }
    }
@@ -3953,9 +3862,8 @@ mod tests {
    use crate::DEFAULT_PG_VERSION;
    use bytes::BytesMut;
    use hex_literal::hex;
-    use pageserver_api::key::{AUX_KEY_PREFIX, NON_INHERITED_RANGE};
+    use pageserver_api::key::NON_INHERITED_RANGE;
    use pageserver_api::keyspace::KeySpace;
-    use pageserver_api::models::CompactionAlgorithm;
    use rand::{thread_rng, Rng};
    use tests::storage_layer::ValuesReconstructState;
    use tests::timeline::{GetVectoredError, ShutdownMode};
@@ -4595,25 +4503,11 @@ mod tests {
    }

    async fn bulk_insert_compact_gc(
-        tenant: &Tenant,
-        timeline: &Arc<Timeline>,
-        ctx: &RequestContext,
-        lsn: Lsn,
-        repeat: usize,
-        key_count: usize,
-    ) -> anyhow::Result<()> {
-        let compact = true;
-        bulk_insert_maybe_compact_gc(tenant, timeline, ctx, lsn, repeat, key_count, compact).await
-    }
-
-    async fn bulk_insert_maybe_compact_gc(
-        tenant: &Tenant,
-        timeline: &Arc<Timeline>,
+        timeline: Arc<Timeline>,
        ctx: &RequestContext,
        mut lsn: Lsn,
        repeat: usize,
        key_count: usize,
-        compact: bool,
    ) -> anyhow::Result<()> {
        let mut test_key = Key::from_hex("010000000033333333444444445500000000").unwrap();
        let mut blknum = 0;
@@ -4621,8 +4515,6 @@ mod tests {
        // Enforce that key range is monotonously increasing
        let mut keyspace = KeySpaceAccum::new();

-        let cancel = CancellationToken::new();
-
        for _ in 0..repeat {
            for _ in 0..key_count {
                test_key.field6 = blknum;
@@ -4644,19 +4536,22 @@ mod tests {
                blknum += 1;
            }

-            timeline.freeze_and_flush().await?;
-            if compact {
-                // this requires timeline to be &Arc<Timeline>
-                timeline.compact(&cancel, EnumSet::empty(), ctx).await?;
-            }
+            let cutoff = timeline.get_last_record_lsn();

-            // this doesn't really need to use the timeline_id target, but it is closer to what it
-            // originally was.
-            let res = tenant
-                .gc_iteration(Some(timeline.timeline_id), 0, Duration::ZERO, &cancel, ctx)
+            timeline
+                .update_gc_info(
+                    Vec::new(),
+                    cutoff,
+                    Duration::ZERO,
+                    &CancellationToken::new(),
+                    ctx,
+                )
                .await?;
-
-            assert_eq!(res.layers_removed, 0, "this never removes anything");
+            timeline.freeze_and_flush().await?;
+            timeline
+                .compact(&CancellationToken::new(), EnumSet::empty(), ctx)
+                .await?;
+            timeline.gc().await?;
        }

        Ok(())
@@ -4675,7 +4570,7 @@ mod tests {
            .await?;

        let lsn = Lsn(0x10);
-        bulk_insert_compact_gc(&tenant, &tline, &ctx, lsn, 50, 10000).await?;
+        bulk_insert_compact_gc(tline.clone(), &ctx, lsn, 50, 10000).await?;

        Ok(())
    }
@@ -4706,7 +4601,7 @@ mod tests {
            .await?;

        let lsn = Lsn(0x10);
-        bulk_insert_compact_gc(&tenant, &tline, &ctx, lsn, 50, 10000).await?;
+        bulk_insert_compact_gc(tline.clone(), &ctx, lsn, 50, 10000).await?;

        let guard = tline.layers.read().await;
        guard.layer_map().dump(true, &ctx).await?;
@@ -4819,7 +4714,15 @@ mod tests {
            .await;

        let images = vectored_res?;
-        assert!(images.is_empty());
+        let mut key = NON_INHERITED_RANGE.start;
+        while key < NON_INHERITED_RANGE.end {
+            assert!(matches!(
+                images[&key],
+                Err(PageReconstructError::MissingKey(_))
+            ));
+            key = key.next();
+        }
+
        Ok(())
    }

@@ -5130,29 +5033,13 @@ mod tests {

    #[tokio::test]
    async fn test_random_updates() -> anyhow::Result<()> {
-        let names_algorithms = [
-            ("test_random_updates_legacy", CompactionAlgorithm::Legacy),
-            ("test_random_updates_tiered", CompactionAlgorithm::Tiered),
-        ];
-        for (name, algorithm) in names_algorithms {
-            test_random_updates_algorithm(name, algorithm).await?;
-        }
-        Ok(())
-    }
-
-    async fn test_random_updates_algorithm(
-        name: &'static str,
-        compaction_algorithm: CompactionAlgorithm,
-    ) -> anyhow::Result<()> {
-        let mut harness = TenantHarness::create(name)?;
-        harness.tenant_conf.compaction_algorithm = compaction_algorithm;
+        let harness = TenantHarness::create("test_random_updates")?;
        let (tenant, ctx) = harness.load().await;
        let tline = tenant
            .create_test_timeline(TIMELINE_ID, Lsn(0x10), DEFAULT_PG_VERSION, &ctx)
            .await?;

        const NUM_KEYS: usize = 1000;
-        let cancel = CancellationToken::new();

        let mut test_key = Key::from_hex("010000000033333333444444445500000000").unwrap();

@@ -5211,11 +5098,22 @@ mod tests {
                );
            }

-            // Perform a cycle of flush, and GC
-            tline.freeze_and_flush().await?;
-            tenant
-                .gc_iteration(Some(tline.timeline_id), 0, Duration::ZERO, &cancel, &ctx)
+            // Perform a cycle of flush, compact, and GC
+            let cutoff = tline.get_last_record_lsn();
+            tline
+                .update_gc_info(
+                    Vec::new(),
+                    cutoff,
+                    Duration::ZERO,
+                    &CancellationToken::new(),
+                    &ctx,
+                )
                .await?;
+            tline.freeze_and_flush().await?;
+            tline
+                .compact(&CancellationToken::new(), EnumSet::empty(), &ctx)
+                .await?;
+            tline.gc().await?;
        }

        Ok(())
@@ -5236,8 +5134,6 @@ mod tests {

        let mut keyspace = KeySpaceAccum::new();

-        let cancel = CancellationToken::new();
-
        // Track when each page was last modified. Used to assert that
        // a read sees the latest page version.
        let mut updated = [Lsn(0); NUM_KEYS];
@@ -5301,11 +5197,21 @@ mod tests {
            }

            // Perform a cycle of flush, compact, and GC
-            tline.freeze_and_flush().await?;
-            tline.compact(&cancel, EnumSet::empty(), &ctx).await?;
-            tenant
-                .gc_iteration(Some(tline.timeline_id), 0, Duration::ZERO, &cancel, &ctx)
+            let cutoff = tline.get_last_record_lsn();
+            tline
+                .update_gc_info(
+                    Vec::new(),
+                    cutoff,
+                    Duration::ZERO,
+                    &CancellationToken::new(),
+                    &ctx,
+                )
                .await?;
+            tline.freeze_and_flush().await?;
+            tline
+                .compact(&CancellationToken::new(), EnumSet::empty(), &ctx)
+                .await?;
+            tline.gc().await?;
        }

        Ok(())
@@ -5487,140 +5393,19 @@ mod tests {

    #[tokio::test]
    async fn test_read_at_max_lsn() -> anyhow::Result<()> {
-        let names_algorithms = [
-            ("test_read_at_max_lsn_legacy", CompactionAlgorithm::Legacy),
-            ("test_read_at_max_lsn_tiered", CompactionAlgorithm::Tiered),
-        ];
-        for (name, algorithm) in names_algorithms {
-            test_read_at_max_lsn_algorithm(name, algorithm).await?;
-        }
-        Ok(())
-    }
-
-    async fn test_read_at_max_lsn_algorithm(
-        name: &'static str,
-        compaction_algorithm: CompactionAlgorithm,
-    ) -> anyhow::Result<()> {
-        let mut harness = TenantHarness::create(name)?;
-        harness.tenant_conf.compaction_algorithm = compaction_algorithm;
+        let harness = TenantHarness::create("test_read_at_max_lsn")?;
        let (tenant, ctx) = harness.load().await;
        let tline = tenant
            .create_test_timeline(TIMELINE_ID, Lsn(0x08), DEFAULT_PG_VERSION, &ctx)
            .await?;

        let lsn = Lsn(0x10);
-        let compact = false;
-        bulk_insert_maybe_compact_gc(&tenant, &tline, &ctx, lsn, 50, 10000, compact).await?;
+        bulk_insert_compact_gc(tline.clone(), &ctx, lsn, 50, 10000).await?;

        let test_key = Key::from_hex("010000000033333333444444445500000000").unwrap();
        let read_lsn = Lsn(u64::MAX - 1);

-        let result = tline.get(test_key, read_lsn, &ctx).await;
-        assert!(result.is_ok(), "result is not Ok: {}", result.unwrap_err());
-
-        Ok(())
-    }
-
-    #[tokio::test]
-    async fn test_metadata_scan() -> anyhow::Result<()> {
-        let harness = TenantHarness::create("test_metadata_scan")?;
-        let (tenant, ctx) = harness.load().await;
-        let tline = tenant
-            .create_test_timeline(TIMELINE_ID, Lsn(0x10), DEFAULT_PG_VERSION, &ctx)
-            .await?;
-
-        const NUM_KEYS: usize = 1000;
-        const STEP: usize = 100; // random update + scan base_key + idx * STEP
-
-        let cancel = CancellationToken::new();
-
-        let mut base_key = Key::from_hex("000000000033333333444444445500000000").unwrap();
-        base_key.field1 = AUX_KEY_PREFIX;
-        let mut test_key = base_key;
-
-        // Track when each page was last modified. Used to assert that
-        // a read sees the latest page version.
-        let mut updated = [Lsn(0); NUM_KEYS];
-
-        let mut lsn = Lsn(0x10);
-        #[allow(clippy::needless_range_loop)]
-        for blknum in 0..NUM_KEYS {
-            lsn = Lsn(lsn.0 + 0x10);
-            test_key.field6 = (blknum * STEP) as u32;
-            let mut writer = tline.writer().await;
-            writer
-                .put(
-                    test_key,
-                    lsn,
-                    &Value::Image(test_img(&format!("{} at {}", blknum, lsn))),
-                    &ctx,
-                )
-                .await?;
-            writer.finish_write(lsn);
-            updated[blknum] = lsn;
-            drop(writer);
-        }
-
-        let keyspace = KeySpace::single(base_key..base_key.add((NUM_KEYS * STEP) as u32));
-
-        for _ in 0..10 {
-            // Read all the blocks
-            for (blknum, last_lsn) in updated.iter().enumerate() {
-                test_key.field6 = (blknum * STEP) as u32;
-                assert_eq!(
-                    tline.get(test_key, lsn, &ctx).await?,
-                    test_img(&format!("{} at {}", blknum, last_lsn))
-                );
-            }
-
-            let mut cnt = 0;
-            for (key, value) in tline
-                .get_vectored_impl(
-                    keyspace.clone(),
-                    lsn,
-                    ValuesReconstructState::default(),
-                    &ctx,
-                )
-                .await?
-            {
-                let blknum = key.field6 as usize;
-                let value = value?;
-                assert!(blknum % STEP == 0);
-                let blknum = blknum / STEP;
-                assert_eq!(
-                    value,
-                    test_img(&format!("{} at {}", blknum, updated[blknum]))
-                );
-                cnt += 1;
-            }
-
-            assert_eq!(cnt, NUM_KEYS);
-
-            for _ in 0..NUM_KEYS {
-                lsn = Lsn(lsn.0 + 0x10);
-                let blknum = thread_rng().gen_range(0..NUM_KEYS);
-                test_key.field6 = (blknum * STEP) as u32;
-                let mut writer = tline.writer().await;
-                writer
-                    .put(
-                        test_key,
-                        lsn,
-                        &Value::Image(test_img(&format!("{} at {}", blknum, lsn))),
-                        &ctx,
-                    )
-                    .await?;
-                writer.finish_write(lsn);
-                drop(writer);
-                updated[blknum] = lsn;
-            }
-
-            // Perform a cycle of flush, compact, and GC
-            tline.freeze_and_flush().await?;
-            tline.compact(&cancel, EnumSet::empty(), &ctx).await?;
-            tenant
-                .gc_iteration(Some(tline.timeline_id), 0, Duration::ZERO, &cancel, &ctx)
-                .await?;
-        }
+        assert!(tline.get(test_key, read_lsn, &ctx).await.is_ok());

        Ok(())
    }
--- a/pageserver/src/tenant/blob_io.rs
+++ b/pageserver/src/tenant/blob_io.rs
@@ -121,7 +121,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
        self.offset
    }

-    const CAPACITY: usize = if BUFFERED { 64 * 1024 } else { 0 };
+    const CAPACITY: usize = if BUFFERED { PAGE_SZ } else { 0 };

    /// Writes the given buffer directly to the underlying `VirtualFile`.
    /// You need to make sure that the internal buffer is empty, otherwise
@@ -130,9 +130,8 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
    async fn write_all_unbuffered<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        src_buf: B,
-        ctx: &RequestContext,
    ) -> (B::Buf, Result<(), Error>) {
-        let (src_buf, res) = self.inner.write_all(src_buf, ctx).await;
+        let (src_buf, res) = self.inner.write_all(src_buf).await;
        let nbytes = match res {
            Ok(nbytes) => nbytes,
            Err(e) => return (src_buf, Err(e)),
@@ -143,9 +142,9 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {

    #[inline(always)]
    /// Flushes the internal buffer to the underlying `VirtualFile`.
-    pub async fn flush_buffer(&mut self, ctx: &RequestContext) -> Result<(), Error> {
+    pub async fn flush_buffer(&mut self) -> Result<(), Error> {
        let buf = std::mem::take(&mut self.buf);
-        let (mut buf, res) = self.inner.write_all(buf, ctx).await;
+        let (mut buf, res) = self.inner.write_all(buf).await;
        res?;
        buf.clear();
        self.buf = buf;
@@ -166,11 +165,10 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
    async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        src_buf: B,
-        ctx: &RequestContext,
    ) -> (B::Buf, Result<(), Error>) {
        if !BUFFERED {
            assert!(self.buf.is_empty());
-            return self.write_all_unbuffered(src_buf, ctx).await;
+            return self.write_all_unbuffered(src_buf).await;
        }
        let remaining = Self::CAPACITY - self.buf.len();
        let src_buf_len = src_buf.bytes_init();
@@ -185,7 +183,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
        }
        // Then, if the buffer is full, flush it out
        if self.buf.len() == Self::CAPACITY {
-            if let Err(e) = self.flush_buffer(ctx).await {
+            if let Err(e) = self.flush_buffer().await {
                return (Slice::into_inner(src_buf), Err(e));
            }
        }
@@ -201,7 +199,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
                assert_eq!(copied, src_buf.len());
                Slice::into_inner(src_buf)
            } else {
-                let (src_buf, res) = self.write_all_unbuffered(src_buf, ctx).await;
+                let (src_buf, res) = self.write_all_unbuffered(src_buf).await;
                if let Err(e) = res {
                    return (src_buf, Err(e));
                }
@@ -218,7 +216,6 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
    pub async fn write_blob<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        srcbuf: B,
-        ctx: &RequestContext,
    ) -> (B::Buf, Result<u64, Error>) {
        let offset = self.offset;

@@ -230,7 +227,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
            if len < 128 {
                // Short blob. Write a 1-byte length header
                io_buf.put_u8(len as u8);
-                self.write_all(io_buf, ctx).await
+                self.write_all(io_buf).await
            } else {
                // Write a 4-byte length header
                if len > 0x7fff_ffff {
@@ -245,7 +242,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
                let mut len_buf = (len as u32).to_be_bytes();
                len_buf[0] |= 0x80;
                io_buf.extend_from_slice(&len_buf[..]);
-                self.write_all(io_buf, ctx).await
+                self.write_all(io_buf).await
            }
        }
        .await;
@@ -254,7 +251,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
            Ok(_) => (),
            Err(e) => return (Slice::into_inner(srcbuf.slice(..)), Err(e)),
        }
-        let (srcbuf, res) = self.write_all(srcbuf, ctx).await;
+        let (srcbuf, res) = self.write_all(srcbuf).await;
        (srcbuf, res.map(|_| offset))
    }
 }
@@ -264,8 +261,8 @@ impl BlobWriter<true> {
    ///
    /// This function flushes the internal buffer before giving access
    /// to the underlying `VirtualFile`.
-    pub async fn into_inner(mut self, ctx: &RequestContext) -> Result<VirtualFile, Error> {
-        self.flush_buffer(ctx).await?;
+    pub async fn into_inner(mut self) -> Result<VirtualFile, Error> {
+        self.flush_buffer().await?;
        Ok(self.inner)
    }

@@ -302,16 +299,16 @@ mod tests {
            let file = VirtualFile::create(pathbuf.as_path()).await?;
            let mut wtr = BlobWriter::<BUFFERED>::new(file, 0);
            for blob in blobs.iter() {
-                let (_, res) = wtr.write_blob(blob.clone(), &ctx).await;
+                let (_, res) = wtr.write_blob(blob.clone()).await;
                let offs = res?;
                offsets.push(offs);
            }
            // Write out one page worth of zeros so that we can
            // read again with read_blk
-            let (_, res) = wtr.write_blob(vec![0; PAGE_SZ], &ctx).await;
+            let (_, res) = wtr.write_blob(vec![0; PAGE_SZ]).await;
            let offs = res?;
            println!("Writing final blob at offs={offs}");
-            wtr.flush_buffer(&ctx).await?;
+            wtr.flush_buffer().await?;
        }

        let file = VirtualFile::open(pathbuf.as_path()).await?;
--- a/pageserver/src/tenant/config.rs
+++ b/pageserver/src/tenant/config.rs
@@ -369,10 +369,6 @@ pub struct TenantConf {
    // How much WAL must be ingested before checking again whether a new image layer is required.
    // Expresed in multiples of checkpoint distance.
    pub image_layer_creation_check_threshold: u8,
-
-    /// Switch to aux file v2. Switching this flag requires the user has not written any aux file into
-    /// the storage before, and this flag cannot be switched back. Otherwise there will be data corruptions.
-    pub switch_to_aux_file_v2: bool,
 }

 /// Same as TenantConf, but this struct preserves the information about
@@ -468,10 +464,6 @@ pub struct TenantConfOpt {

    #[serde(skip_serializing_if = "Option::is_none")]
    pub image_layer_creation_check_threshold: Option<u8>,
-
-    #[serde(skip_serializing_if = "Option::is_none")]
-    #[serde(default)]
-    pub switch_to_aux_file_v2: Option<bool>,
 }

 impl TenantConfOpt {
@@ -529,9 +521,6 @@ impl TenantConfOpt {
            image_layer_creation_check_threshold: self
                .image_layer_creation_check_threshold
                .unwrap_or(global_conf.image_layer_creation_check_threshold),
-            switch_to_aux_file_v2: self
-                .switch_to_aux_file_v2
-                .unwrap_or(global_conf.switch_to_aux_file_v2),
        }
    }
 }
@@ -573,7 +562,6 @@ impl Default for TenantConf {
            lazy_slru_download: false,
            timeline_get_throttle: crate::tenant::throttle::Config::disabled(),
            image_layer_creation_check_threshold: DEFAULT_IMAGE_LAYER_CREATION_CHECK_THRESHOLD,
-            switch_to_aux_file_v2: false,
        }
    }
 }
@@ -648,7 +636,6 @@ impl From<TenantConfOpt> for models::TenantConfig {
            lazy_slru_download: value.lazy_slru_download,
            timeline_get_throttle: value.timeline_get_throttle.map(ThrottleConfig::from),
            image_layer_creation_check_threshold: value.image_layer_creation_check_threshold,
-            switch_to_aux_file_v2: value.switch_to_aux_file_v2,
        }
    }
 }
--- a/pageserver/src/tenant/delete.rs
+++ b/pageserver/src/tenant/delete.rs
@@ -585,20 +585,9 @@ impl DeleteTenantFlow {

                    // FIXME: we should not be modifying this from outside of mgr.rs.
                    // This will go away when we simplify deletion (https://github.com/neondatabase/neon/issues/5080)
-
-                    // Update stats
-                    match &removed {
-                        TenantsMapRemoveResult::Occupied(slot) => {
-                            crate::metrics::TENANT_MANAGER.slot_removed(slot);
-                        }
-                        TenantsMapRemoveResult::InProgress(barrier) => {
-                            crate::metrics::TENANT_MANAGER
-                                .slot_removed(&TenantSlot::InProgress(barrier.clone()));
-                        }
-                        TenantsMapRemoveResult::Vacant => {
-                            // Nothing changed in map, no metric update
-                        }
-                    }
+                    crate::metrics::TENANT_MANAGER
+                        .tenant_slots
+                        .set(locked.len() as u64);

                    match removed {
                        TenantsMapRemoveResult::Occupied(TenantSlot::Attached(tenant)) => {
--- a/pageserver/src/tenant/ephemeral_file.rs
+++ b/pageserver/src/tenant/ephemeral_file.rs
@@ -3,26 +3,36 @@

 use crate::config::PageServerConf;
 use crate::context::RequestContext;
-use crate::page_cache;
+use crate::page_cache::{self, PAGE_SZ};
 use crate::tenant::block_io::{BlockCursor, BlockLease, BlockReader};
 use crate::virtual_file::{self, VirtualFile};
+use bytes::BytesMut;
 use camino::Utf8PathBuf;
 use pageserver_api::shard::TenantShardId;
+use std::cmp::min;

-use std::io;
+use std::io::{self, ErrorKind};
+use std::ops::DerefMut;
 use std::sync::atomic::AtomicU64;
+use tracing::*;
 use utils::id::TimelineId;

 pub struct EphemeralFile {
+    page_cache_file_id: page_cache::FileId,
+
    _tenant_shard_id: TenantShardId,
    _timeline_id: TimelineId,
-
-    rw: page_caching::RW,
+    file: VirtualFile,
+    len: u64,
+    /// An ephemeral file is append-only.
+    /// We keep the last page, which can still be modified, in [`Self::mutable_tail`].
+    /// The other pages, which can no longer be modified, are accessed through the page cache.
+    ///
+    /// None <=> IO is ongoing.
+    /// Size is fixed to PAGE_SZ at creation time and must not be changed.
+    mutable_tail: Option<BytesMut>,
 }

-mod page_caching;
-mod zero_padded_read_write;
-
 impl EphemeralFile {
    pub async fn create(
        conf: &PageServerConf,
@@ -49,18 +59,21 @@ impl EphemeralFile {
        .await?;

        Ok(EphemeralFile {
+            page_cache_file_id: page_cache::next_file_id(),
            _tenant_shard_id: tenant_shard_id,
            _timeline_id: timeline_id,
-            rw: page_caching::RW::new(file),
+            file,
+            len: 0,
+            mutable_tail: Some(BytesMut::zeroed(PAGE_SZ)),
        })
    }

    pub(crate) fn len(&self) -> u64 {
-        self.rw.bytes_written()
+        self.len
    }

-    pub(crate) fn page_cache_file_id(&self) -> page_cache::FileId {
-        self.rw.page_cache_file_id()
+    pub(crate) fn id(&self) -> page_cache::FileId {
+        self.page_cache_file_id
    }

    pub(crate) async fn read_blk(
@@ -68,7 +81,44 @@ impl EphemeralFile {
        blknum: u32,
        ctx: &RequestContext,
    ) -> Result<BlockLease, io::Error> {
-        self.rw.read_blk(blknum, ctx).await
+        let flushed_blknums = 0..self.len / PAGE_SZ as u64;
+        if flushed_blknums.contains(&(blknum as u64)) {
+            let cache = page_cache::get();
+            match cache
+                .read_immutable_buf(self.page_cache_file_id, blknum, ctx)
+                .await
+                .map_err(|e| {
+                    std::io::Error::new(
+                        std::io::ErrorKind::Other,
+                        // order path before error because error is anyhow::Error => might have many contexts
+                        format!(
+                            "ephemeral file: read immutable page #{}: {}: {:#}",
+                            blknum, self.file.path, e,
+                        ),
+                    )
+                })? {
+                page_cache::ReadBufResult::Found(guard) => {
+                    return Ok(BlockLease::PageReadGuard(guard))
+                }
+                page_cache::ReadBufResult::NotFound(write_guard) => {
+                    let write_guard = self
+                        .file
+                        .read_exact_at_page(write_guard, blknum as u64 * PAGE_SZ as u64)
+                        .await?;
+                    let read_guard = write_guard.mark_valid();
+                    return Ok(BlockLease::PageReadGuard(read_guard));
+                }
+            };
+        } else {
+            debug_assert_eq!(blknum as u64, self.len / PAGE_SZ as u64);
+            Ok(BlockLease::EphemeralFileMutableTail(
+                self.mutable_tail
+                    .as_deref()
+                    .expect("we're not doing IO, it must be Some()")
+                    .try_into()
+                    .expect("we ensure that it's always PAGE_SZ"),
+            ))
+        }
    }

    pub(crate) async fn write_blob(
@@ -76,22 +126,137 @@ impl EphemeralFile {
        srcbuf: &[u8],
        ctx: &RequestContext,
    ) -> Result<u64, io::Error> {
-        let pos = self.rw.bytes_written();
+        struct Writer<'a> {
+            ephemeral_file: &'a mut EphemeralFile,
+            /// The block to which the next [`push_bytes`] will write.
+            blknum: u32,
+            /// The offset inside the block identified by [`blknum`] to which [`push_bytes`] will write.
+            off: usize,
+        }
+        impl<'a> Writer<'a> {
+            fn new(ephemeral_file: &'a mut EphemeralFile) -> io::Result<Writer<'a>> {
+                Ok(Writer {
+                    blknum: (ephemeral_file.len / PAGE_SZ as u64) as u32,
+                    off: (ephemeral_file.len % PAGE_SZ as u64) as usize,
+                    ephemeral_file,
+                })
+            }
+            #[inline(always)]
+            async fn push_bytes(
+                &mut self,
+                src: &[u8],
+                ctx: &RequestContext,
+            ) -> Result<(), io::Error> {
+                let mut src_remaining = src;
+                while !src_remaining.is_empty() {
+                    let dst_remaining = &mut self
+                        .ephemeral_file
+                        .mutable_tail
+                        .as_deref_mut()
+                        .expect("IO is not yet ongoing")[self.off..];
+                    let n = min(dst_remaining.len(), src_remaining.len());
+                    dst_remaining[..n].copy_from_slice(&src_remaining[..n]);
+                    self.off += n;
+                    src_remaining = &src_remaining[n..];
+                    if self.off == PAGE_SZ {
+                        let mutable_tail = std::mem::take(&mut self.ephemeral_file.mutable_tail)
+                            .expect("IO is not yet ongoing");
+                        let (mutable_tail, res) = self
+                            .ephemeral_file
+                            .file
+                            .write_all_at(mutable_tail, self.blknum as u64 * PAGE_SZ as u64)
+                            .await;
+                        // TODO: If we panic before we can put the mutable_tail back, subsequent calls will fail.
+                        // I.e., the IO isn't retryable if we panic.
+                        self.ephemeral_file.mutable_tail = Some(mutable_tail);
+                        match res {
+                            Ok(_) => {
+                                // Pre-warm the page cache with what we just wrote.
+                                // This isn't necessary for coherency/correctness, but it's how we've always done it.
+                                let cache = page_cache::get();
+                                match cache
+                                    .read_immutable_buf(
+                                        self.ephemeral_file.page_cache_file_id,
+                                        self.blknum,
+                                        ctx,
+                                    )
+                                    .await
+                                {
+                                    Ok(page_cache::ReadBufResult::Found(_guard)) => {
+                                        // This function takes &mut self, so, it shouldn't be possible to reach this point.
+                                        unreachable!("we just wrote blknum {} and this function takes &mut self, so, no concurrent read_blk is possible", self.blknum);
+                                    }
+                                    Ok(page_cache::ReadBufResult::NotFound(mut write_guard)) => {
+                                        let buf: &mut [u8] = write_guard.deref_mut();
+                                        debug_assert_eq!(buf.len(), PAGE_SZ);
+                                        buf.copy_from_slice(
+                                            self.ephemeral_file
+                                                .mutable_tail
+                                                .as_deref()
+                                                .expect("IO is not ongoing"),
+                                        );
+                                        let _ = write_guard.mark_valid();
+                                        // pre-warm successful
+                                    }
+                                    Err(e) => {
+                                        error!("ephemeral_file write_blob failed to get immutable buf to pre-warm page cache: {e:?}");
+                                        // fail gracefully, it's not the end of the world if we can't pre-warm the cache here
+                                    }
+                                }
+                                // Zero the buffer for re-use.
+                                // Zeroing is critical for correcntess because the write_blob code below
+                                // and similarly read_blk expect zeroed pages.
+                                self.ephemeral_file
+                                    .mutable_tail
+                                    .as_deref_mut()
+                                    .expect("IO is not ongoing")
+                                    .fill(0);
+                                // This block is done, move to next one.
+                                self.blknum += 1;
+                                self.off = 0;
+                            }
+                            Err(e) => {
+                                return Err(std::io::Error::new(
+                                    ErrorKind::Other,
+                                    // order error before path because path is long and error is short
+                                    format!(
+                                        "ephemeral_file: write_blob: write-back full tail blk #{}: {:#}: {}",
+                                        self.blknum,
+                                        e,
+                                        self.ephemeral_file.file.path,
+                                    ),
+                                ));
+                            }
+                        }
+                    }
+                }
+                Ok(())
+            }
+        }
+
+        let pos = self.len;
+        let mut writer = Writer::new(self)?;

        // Write the length field
        if srcbuf.len() < 0x80 {
            // short one-byte length header
            let len_buf = [srcbuf.len() as u8];
-
-            self.rw.write_all_borrowed(&len_buf, ctx).await?;
+            writer.push_bytes(&len_buf, ctx).await?;
        } else {
            let mut len_buf = u32::to_be_bytes(srcbuf.len() as u32);
            len_buf[0] |= 0x80;
-            self.rw.write_all_borrowed(&len_buf, ctx).await?;
+            writer.push_bytes(&len_buf, ctx).await?;
        }

        // Write the payload
-        self.rw.write_all_borrowed(srcbuf, ctx).await?;
+        writer.push_bytes(srcbuf, ctx).await?;
+
+        if srcbuf.len() < 0x80 {
+            self.len += 1;
+        } else {
+            self.len += 4;
+        }
+        self.len += srcbuf.len() as u64;

        Ok(pos)
    }
@@ -106,6 +271,28 @@ pub fn is_ephemeral_file(filename: &str) -> bool {
    }
 }

+impl Drop for EphemeralFile {
+    fn drop(&mut self) {
+        // There might still be pages in the [`crate::page_cache`] for this file.
+        // We leave them there, [`crate::page_cache::PageCache::find_victim`] will evict them when needed.
+
+        // unlink the file
+        let res = std::fs::remove_file(&self.file.path);
+        if let Err(e) = res {
+            if e.kind() != std::io::ErrorKind::NotFound {
+                // just never log the not found errors, we cannot do anything for them; on detach
+                // the tenant directory is already gone.
+                //
+                // not found files might also be related to https://github.com/neondatabase/neon/issues/2442
+                error!(
+                    "could not remove ephemeral file '{}': {}",
+                    self.file.path, e
+                );
+            }
+        }
+    }
+}
+
 impl BlockReader for EphemeralFile {
    fn block_cursor(&self) -> super::block_io::BlockCursor<'_> {
        BlockCursor::new(super::block_io::BlockReaderRef::EphemeralFile(self))
--- a/pageserver/src/tenant/ephemeral_file/page_caching.rs
+++ b/pageserver/src/tenant/ephemeral_file/page_caching.rs
@@ -1,223 +0,0 @@
-//! Wrapper around [`super::zero_padded_read_write::RW`] that uses the
-//! [`crate::page_cache`] to serve reads that need to go to the underlying [`VirtualFile`].
-
-use crate::context::RequestContext;
-use crate::page_cache::{self, PAGE_SZ};
-use crate::tenant::block_io::BlockLease;
-use crate::virtual_file::VirtualFile;
-
-use once_cell::sync::Lazy;
-use std::io::{self, ErrorKind};
-use tokio_epoll_uring::BoundedBuf;
-use tracing::*;
-
-use super::zero_padded_read_write;
-
-/// See module-level comment.
-pub struct RW {
-    page_cache_file_id: page_cache::FileId,
-    rw: super::zero_padded_read_write::RW<PreWarmingWriter>,
-}
-
-impl RW {
-    pub fn new(file: VirtualFile) -> Self {
-        let page_cache_file_id = page_cache::next_file_id();
-        Self {
-            page_cache_file_id,
-            rw: super::zero_padded_read_write::RW::new(PreWarmingWriter::new(
-                page_cache_file_id,
-                file,
-            )),
-        }
-    }
-
-    pub fn page_cache_file_id(&self) -> page_cache::FileId {
-        self.page_cache_file_id
-    }
-
-    pub(crate) async fn write_all_borrowed(
-        &mut self,
-        srcbuf: &[u8],
-        ctx: &RequestContext,
-    ) -> Result<usize, io::Error> {
-        // It doesn't make sense to proactively fill the page cache on the Pageserver write path
-        // because Compute is unlikely to access recently written data.
-        self.rw.write_all_borrowed(srcbuf, ctx).await
-    }
-
-    pub(crate) fn bytes_written(&self) -> u64 {
-        self.rw.bytes_written()
-    }
-
-    pub(crate) async fn read_blk(
-        &self,
-        blknum: u32,
-        ctx: &RequestContext,
-    ) -> Result<BlockLease, io::Error> {
-        match self.rw.read_blk(blknum).await? {
-            zero_padded_read_write::ReadResult::NeedsReadFromWriter { writer } => {
-                let cache = page_cache::get();
-                match cache
-                    .read_immutable_buf(self.page_cache_file_id, blknum, ctx)
-                    .await
-                    .map_err(|e| {
-                        std::io::Error::new(
-                            std::io::ErrorKind::Other,
-                            // order path before error because error is anyhow::Error => might have many contexts
-                            format!(
-                                "ephemeral file: read immutable page #{}: {}: {:#}",
-                                blknum,
-                                self.rw.as_writer().file.path,
-                                e,
-                            ),
-                        )
-                    })? {
-                    page_cache::ReadBufResult::Found(guard) => {
-                        return Ok(BlockLease::PageReadGuard(guard))
-                    }
-                    page_cache::ReadBufResult::NotFound(write_guard) => {
-                        let write_guard = writer
-                            .file
-                            .read_exact_at_page(write_guard, blknum as u64 * PAGE_SZ as u64)
-                            .await?;
-                        let read_guard = write_guard.mark_valid();
-                        return Ok(BlockLease::PageReadGuard(read_guard));
-                    }
-                }
-            }
-            zero_padded_read_write::ReadResult::ServedFromZeroPaddedMutableTail { buffer } => {
-                Ok(BlockLease::EphemeralFileMutableTail(buffer))
-            }
-        }
-    }
-}
-
-impl Drop for RW {
-    fn drop(&mut self) {
-        // There might still be pages in the [`crate::page_cache`] for this file.
-        // We leave them there, [`crate::page_cache::PageCache::find_victim`] will evict them when needed.
-
-        // unlink the file
-        let res = std::fs::remove_file(&self.rw.as_writer().file.path);
-        if let Err(e) = res {
-            if e.kind() != std::io::ErrorKind::NotFound {
-                // just never log the not found errors, we cannot do anything for them; on detach
-                // the tenant directory is already gone.
-                //
-                // not found files might also be related to https://github.com/neondatabase/neon/issues/2442
-                error!(
-                    "could not remove ephemeral file '{}': {}",
-                    self.rw.as_writer().file.path,
-                    e
-                );
-            }
-        }
-    }
-}
-
-struct PreWarmingWriter {
-    nwritten_blocks: u32,
-    page_cache_file_id: page_cache::FileId,
-    file: VirtualFile,
-}
-
-impl PreWarmingWriter {
-    fn new(page_cache_file_id: page_cache::FileId, file: VirtualFile) -> Self {
-        Self {
-            nwritten_blocks: 0,
-            page_cache_file_id,
-            file,
-        }
-    }
-}
-
-impl crate::virtual_file::owned_buffers_io::write::OwnedAsyncWriter for PreWarmingWriter {
-    async fn write_all<
-        B: tokio_epoll_uring::BoundedBuf<Buf = Buf>,
-        Buf: tokio_epoll_uring::IoBuf + Send,
-    >(
-        &mut self,
-        buf: B,
-        ctx: &RequestContext,
-    ) -> std::io::Result<(usize, B::Buf)> {
-        let buf = buf.slice(..);
-        let saved_bounds = buf.bounds(); // save for reconstructing the Slice from iobuf after the IO is done
-        let check_bounds_stuff_works = if cfg!(test) && cfg!(debug_assertions) {
-            Some(buf.to_vec())
-        } else {
-            None
-        };
-        let buflen = buf.len();
-        assert_eq!(
-            buflen % PAGE_SZ,
-            0,
-            "{buflen} ; we know TAIL_SZ is a PAGE_SZ multiple, and write_buffered_borrowed is used"
-        );
-
-        // Do the IO.
-        let iobuf = match self.file.write_all(buf, ctx).await {
-            (iobuf, Ok(nwritten)) => {
-                assert_eq!(nwritten, buflen);
-                iobuf
-            }
-            (_, Err(e)) => {
-                return Err(std::io::Error::new(
-                    ErrorKind::Other,
-                    // order error before path because path is long and error is short
-                    format!(
-                        "ephemeral_file: write_blob: write-back tail self.nwritten_blocks={}, buflen={}, {:#}: {}",
-                        self.nwritten_blocks, buflen, e, self.file.path,
-                    ),
-                ));
-            }
-        };
-
-        // Reconstruct the Slice (the write path consumed the Slice and returned us the underlying IoBuf)
-        let buf = tokio_epoll_uring::Slice::from_buf_bounds(iobuf, saved_bounds);
-        if let Some(check_bounds_stuff_works) = check_bounds_stuff_works {
-            assert_eq!(&check_bounds_stuff_works, &*buf);
-        }
-
-        // Pre-warm page cache with the contents.
-        // At least in isolated bulk ingest benchmarks (test_bulk_insert.py), the pre-warming
-        // benefits the code that writes InMemoryLayer=>L0 layers.
-        let nblocks = buflen / PAGE_SZ;
-        let nblocks32 = u32::try_from(nblocks).unwrap();
-        let cache = page_cache::get();
-        static CTX: Lazy<RequestContext> = Lazy::new(|| {
-            RequestContext::new(
-                crate::task_mgr::TaskKind::EphemeralFilePreWarmPageCache,
-                crate::context::DownloadBehavior::Error,
-            )
-        });
-        for blknum_in_buffer in 0..nblocks {
-            let blk_in_buffer = &buf[blknum_in_buffer * PAGE_SZ..(blknum_in_buffer + 1) * PAGE_SZ];
-            let blknum = self
-                .nwritten_blocks
-                .checked_add(blknum_in_buffer as u32)
-                .unwrap();
-            match cache
-                .read_immutable_buf(self.page_cache_file_id, blknum, &CTX)
-                .await
-            {
-                Err(e) => {
-                    error!("ephemeral_file write_blob failed to get immutable buf to pre-warm page cache: {e:?}");
-                    // fail gracefully, it's not the end of the world if we can't pre-warm the cache here
-                }
-                Ok(v) => match v {
-                    page_cache::ReadBufResult::Found(_guard) => {
-                        // This function takes &mut self, so, it shouldn't be possible to reach this point.
-                        unreachable!("we just wrote block {blknum} to the VirtualFile, which is owned by Self, \
-                                      and this function takes &mut self, so, no concurrent read_blk is possible");
-                    }
-                    page_cache::ReadBufResult::NotFound(mut write_guard) => {
-                        write_guard.copy_from_slice(blk_in_buffer);
-                        let _ = write_guard.mark_valid();
-                    }
-                },
-            }
-        }
-        self.nwritten_blocks = self.nwritten_blocks.checked_add(nblocks32).unwrap();
-        Ok((buflen, buf.into_inner()))
-    }
-}
--- a/pageserver/src/tenant/ephemeral_file/zero_padded_read_write.rs
+++ b/pageserver/src/tenant/ephemeral_file/zero_padded_read_write.rs
@@ -1,130 +0,0 @@
-//! The heart of how [`super::EphemeralFile`] does its reads and writes.
-//!
-//! # Writes
-//!
-//! [`super::EphemeralFile`] writes small, borrowed buffers using [`RW::write_all_borrowed`].
-//! The [`RW`] batches these into [`TAIL_SZ`] bigger writes, using [`owned_buffers_io::write::BufferedWriter`].
-//!
-//! # Reads
-//!
-//! [`super::EphemeralFile`] always reads full [`PAGE_SZ`]ed blocks using [`RW::read_blk`].
-//!
-//! The [`RW`] serves these reads either from the buffered writer's in-memory buffer
-//! or redirects the caller to read from the underlying [`OwnedAsyncWriter`]
-//! if the read is for the prefix that has already been flushed.
-//!
-//! # Current Usage
-//!
-//! The current user of this module is [`super::page_caching::RW`].
-
-mod zero_padded;
-
-use crate::{
-    context::RequestContext,
-    page_cache::PAGE_SZ,
-    virtual_file::owned_buffers_io::{
-        self,
-        write::{Buffer, OwnedAsyncWriter},
-    },
-};
-
-const TAIL_SZ: usize = 64 * 1024;
-
-/// See module-level comment.
-pub struct RW<W: OwnedAsyncWriter> {
-    buffered_writer: owned_buffers_io::write::BufferedWriter<
-        zero_padded::Buffer<TAIL_SZ>,
-        owned_buffers_io::util::size_tracking_writer::Writer<W>,
-    >,
-}
-
-pub enum ReadResult<'a, W> {
-    NeedsReadFromWriter { writer: &'a W },
-    ServedFromZeroPaddedMutableTail { buffer: &'a [u8; PAGE_SZ] },
-}
-
-impl<W> RW<W>
-where
-    W: OwnedAsyncWriter,
-{
-    pub fn new(writer: W) -> Self {
-        let bytes_flushed_tracker =
-            owned_buffers_io::util::size_tracking_writer::Writer::new(writer);
-        let buffered_writer = owned_buffers_io::write::BufferedWriter::new(
-            bytes_flushed_tracker,
-            zero_padded::Buffer::default(),
-        );
-        Self { buffered_writer }
-    }
-
-    pub(crate) fn as_writer(&self) -> &W {
-        self.buffered_writer.as_inner().as_inner()
-    }
-
-    pub async fn write_all_borrowed(
-        &mut self,
-        buf: &[u8],
-        ctx: &RequestContext,
-    ) -> std::io::Result<usize> {
-        self.buffered_writer.write_buffered_borrowed(buf, ctx).await
-    }
-
-    pub fn bytes_written(&self) -> u64 {
-        let flushed_offset = self.buffered_writer.as_inner().bytes_written();
-        let buffer: &zero_padded::Buffer<TAIL_SZ> = self.buffered_writer.inspect_buffer();
-        flushed_offset + u64::try_from(buffer.pending()).unwrap()
-    }
-
-    pub(crate) async fn read_blk(&self, blknum: u32) -> Result<ReadResult<'_, W>, std::io::Error> {
-        let flushed_offset = self.buffered_writer.as_inner().bytes_written();
-        let buffer: &zero_padded::Buffer<TAIL_SZ> = self.buffered_writer.inspect_buffer();
-        let buffered_offset = flushed_offset + u64::try_from(buffer.pending()).unwrap();
-        let read_offset = (blknum as u64) * (PAGE_SZ as u64);
-
-        // The trailing page ("block") might only be partially filled,
-        // yet the blob_io code relies on us to return a full PAGE_SZed slice anyway.
-        // Moreover, it has to be zero-padded, because when we still had
-        // a write-back page cache, it provided pre-zeroed pages, and blob_io came to rely on it.
-        // DeltaLayer probably has the same issue, not sure why it needs no special treatment.
-        // => check here that the read doesn't go beyond this potentially trailing
-        // => the zero-padding is done in the `else` branch below
-        let blocks_written = if buffered_offset % (PAGE_SZ as u64) == 0 {
-            buffered_offset / (PAGE_SZ as u64)
-        } else {
-            (buffered_offset / (PAGE_SZ as u64)) + 1
-        };
-        if (blknum as u64) >= blocks_written {
-            return Err(std::io::Error::new(std::io::ErrorKind::Other, anyhow::anyhow!("read past end of ephemeral_file: read=0x{read_offset:x} buffered=0x{buffered_offset:x} flushed=0x{flushed_offset}")));
-        }
-
-        // assertions for the `if-else` below
-        assert_eq!(
-            flushed_offset % (TAIL_SZ as u64), 0,
-            "we only use write_buffered_borrowed to write to the buffered writer, so it's guaranteed that flushes happen buffer.cap()-sized chunks"
-        );
-        assert_eq!(
-            flushed_offset % (PAGE_SZ as u64),
-            0,
-            "the logic below can't handle if the page is spread across the flushed part and the buffer"
-        );
-
-        if read_offset < flushed_offset {
-            assert!(read_offset + (PAGE_SZ as u64) <= flushed_offset);
-            Ok(ReadResult::NeedsReadFromWriter {
-                writer: self.as_writer(),
-            })
-        } else {
-            let read_offset_in_buffer = read_offset
-                .checked_sub(flushed_offset)
-                .expect("would have taken `if` branch instead of this one");
-            let read_offset_in_buffer = usize::try_from(read_offset_in_buffer).unwrap();
-            let zero_padded_slice = buffer.as_zero_padded_slice();
-            let page = &zero_padded_slice[read_offset_in_buffer..(read_offset_in_buffer + PAGE_SZ)];
-            Ok(ReadResult::ServedFromZeroPaddedMutableTail {
-                buffer: page
-                    .try_into()
-                    .expect("the slice above got it as page-size slice"),
-            })
-        }
-    }
-}
--- a/pageserver/src/tenant/ephemeral_file/zero_padded_read_write/zero_padded.rs
+++ b/pageserver/src/tenant/ephemeral_file/zero_padded_read_write/zero_padded.rs
@@ -1,108 +0,0 @@
-//! A [`crate::virtual_file::owned_buffers_io::write::Buffer`] whose
-//! unwritten range is guaranteed to be zero-initialized.
-//! This is used by [`crate::tenant::ephemeral_file::zero_padded_read_write::RW::read_blk`]
-//! to serve page-sized reads of the trailing page when the trailing page has only been partially filled.
-
-use std::mem::MaybeUninit;
-
-/// See module-level comment.
-pub struct Buffer<const N: usize> {
-    allocation: Box<[u8; N]>,
-    written: usize,
-}
-
-impl<const N: usize> Default for Buffer<N> {
-    fn default() -> Self {
-        Self {
-            allocation: Box::new(
-                // SAFETY: zeroed memory is a valid [u8; N]
-                unsafe { MaybeUninit::zeroed().assume_init() },
-            ),
-            written: 0,
-        }
-    }
-}
-
-impl<const N: usize> Buffer<N> {
-    #[inline(always)]
-    fn invariants(&self) {
-        // don't check by default, unoptimized is too expensive even for debug mode
-        if false {
-            debug_assert!(self.written <= N, "{}", self.written);
-            debug_assert!(self.allocation[self.written..N].iter().all(|v| *v == 0));
-        }
-    }
-
-    pub fn as_zero_padded_slice(&self) -> &[u8; N] {
-        &self.allocation
-    }
-}
-
-impl<const N: usize> crate::virtual_file::owned_buffers_io::write::Buffer for Buffer<N> {
-    type IoBuf = Self;
-
-    fn cap(&self) -> usize {
-        self.allocation.len()
-    }
-
-    fn extend_from_slice(&mut self, other: &[u8]) {
-        self.invariants();
-        let remaining = self.allocation.len() - self.written;
-        if other.len() > remaining {
-            panic!("calling extend_from_slice() with insufficient remaining capacity");
-        }
-        self.allocation[self.written..(self.written + other.len())].copy_from_slice(other);
-        self.written += other.len();
-        self.invariants();
-    }
-
-    fn pending(&self) -> usize {
-        self.written
-    }
-
-    fn flush(self) -> tokio_epoll_uring::Slice<Self> {
-        self.invariants();
-        let written = self.written;
-        tokio_epoll_uring::BoundedBuf::slice(self, 0..written)
-    }
-
-    fn reuse_after_flush(iobuf: Self::IoBuf) -> Self {
-        let Self {
-            mut allocation,
-            written,
-        } = iobuf;
-        allocation[0..written].fill(0);
-        let new = Self {
-            allocation,
-            written: 0,
-        };
-        new.invariants();
-        new
-    }
-}
-
-/// We have this trait impl so that the `flush` method in the `Buffer` impl above can produce a
-/// [`tokio_epoll_uring::BoundedBuf::slice`] of the [`Self::written`] range of the data.
-///
-/// Remember that bytes_init is generally _not_ a tracker of the amount
-/// of valid data in the io buffer; we use `Slice` for that.
-/// The `IoBuf` is _only_ for keeping track of uninitialized memory, a bit like MaybeUninit.
-///
-/// SAFETY:
-///
-/// The [`Self::allocation`] is stable becauses boxes are stable.
-/// The memory is zero-initialized, so, bytes_init is always N.
-unsafe impl<const N: usize> tokio_epoll_uring::IoBuf for Buffer<N> {
-    fn stable_ptr(&self) -> *const u8 {
-        self.allocation.as_ptr()
-    }
-
-    fn bytes_init(&self) -> usize {
-        // Yes, N, not self.written; Read the full comment of this impl block!
-        N
-    }
-
-    fn bytes_total(&self) -> usize {
-        N
-    }
-}
--- a/pageserver/src/tenant/layer_map.rs
+++ b/pageserver/src/tenant/layer_map.rs
@@ -588,7 +588,7 @@ impl LayerMap {
            let kr = Key::from_i128(current_key)..Key::from_i128(change_key);
            coverage.push((kr, current_val.take()));
            current_key = change_key;
-            current_val.clone_from(&change_val);
+            current_val = change_val.clone();
        }

        // Add the final interval
@@ -672,12 +672,12 @@ impl LayerMap {
        // Loop through the delta coverage and recurse on each part
        for (change_key, change_val) in version.delta_coverage.range(start..end) {
            // If there's a relevant delta in this part, add 1 and recurse down
-            if let Some(val) = &current_val {
+            if let Some(val) = current_val {
                if val.get_lsn_range().end > lsn.start {
                    let kr = Key::from_i128(current_key)..Key::from_i128(change_key);
                    let lr = lsn.start..val.get_lsn_range().start;
                    if !kr.is_empty() {
-                        let base_count = Self::is_reimage_worthy(val, key) as usize;
+                        let base_count = Self::is_reimage_worthy(&val, key) as usize;
                        let new_limit = limit.map(|l| l - base_count);
                        let max_stacked_deltas_underneath = self.count_deltas(&kr, &lr, new_limit);
                        max_stacked_deltas = std::cmp::max(
@@ -689,17 +689,17 @@ impl LayerMap {
            }

            current_key = change_key;
-            current_val.clone_from(&change_val);
+            current_val = change_val.clone();
        }

        // Consider the last part
-        if let Some(val) = &current_val {
+        if let Some(val) = current_val {
            if val.get_lsn_range().end > lsn.start {
                let kr = Key::from_i128(current_key)..Key::from_i128(end);
                let lr = lsn.start..val.get_lsn_range().start;

                if !kr.is_empty() {
-                    let base_count = Self::is_reimage_worthy(val, key) as usize;
+                    let base_count = Self::is_reimage_worthy(&val, key) as usize;
                    let new_limit = limit.map(|l| l - base_count);
                    let max_stacked_deltas_underneath = self.count_deltas(&kr, &lr, new_limit);
                    max_stacked_deltas = std::cmp::max(
@@ -916,7 +916,6 @@ mod tests {
        assert_eq!(lhs, rhs);
    }

-    #[cfg(test)]
    fn brute_force_range_search(
        layer_map: &LayerMap,
        key_range: Range<Key>,
--- a/pageserver/src/tenant/mgr.rs
+++ b/pageserver/src/tenant/mgr.rs
@@ -2,7 +2,6 @@
 //! page server.

 use camino::{Utf8DirEntry, Utf8Path, Utf8PathBuf};
-use futures::StreamExt;
 use itertools::Itertools;
 use pageserver_api::key::Key;
 use pageserver_api::models::LocationConfigMode;
@@ -246,7 +245,6 @@ impl TenantsMap {
        }
    }

-    #[cfg(all(debug_assertions, not(test)))]
    pub(crate) fn len(&self) -> usize {
        match self {
            TenantsMap::Initializing => 0,
@@ -255,15 +253,17 @@ impl TenantsMap {
    }
 }

-/// Precursor to deletion of a tenant dir: we do a fast rename to a tmp path, and then
-/// the slower actual deletion in the background.
-///
 /// This is "safe" in that that it won't leave behind a partially deleted directory
 /// at the original path, because we rename with TEMP_FILE_SUFFIX before starting deleting
 /// the contents.
 ///
 /// This is pageserver-specific, as it relies on future processes after a crash to check
 /// for TEMP_FILE_SUFFIX when loading things.
+async fn safe_remove_tenant_dir_all(path: impl AsRef<Utf8Path>) -> std::io::Result<()> {
+    let tmp_path = safe_rename_tenant_dir(path).await?;
+    fs::remove_dir_all(tmp_path).await
+}
+
 async fn safe_rename_tenant_dir(path: impl AsRef<Utf8Path>) -> std::io::Result<Utf8PathBuf> {
    let parent = path
        .as_ref()
@@ -286,28 +286,6 @@ async fn safe_rename_tenant_dir(path: impl AsRef<Utf8Path>) -> std::io::Result<U
    Ok(tmp_path)
 }

-/// When we have moved a tenant's content to a temporary directory, we may delete it lazily in
-/// the background, and thereby avoid blocking any API requests on this deletion completing.
-fn spawn_background_purge(tmp_path: Utf8PathBuf) {
-    // Although we are cleaning up the tenant, this task is not meant to be bound by the lifetime of the tenant in memory.
-    // After a tenant is detached, there are no more task_mgr tasks for that tenant_id.
-    let task_tenant_id = None;
-
-    task_mgr::spawn(
-        task_mgr::BACKGROUND_RUNTIME.handle(),
-        TaskKind::MgmtRequest,
-        task_tenant_id,
-        None,
-        "tenant_files_delete",
-        false,
-        async move {
-            fs::remove_dir_all(tmp_path.as_path())
-                .await
-                .with_context(|| format!("tenant directory {:?} deletion", tmp_path))
-        },
-    );
-}
-
 static TENANTS: Lazy<std::sync::RwLock<TenantsMap>> =
    Lazy::new(|| std::sync::RwLock::new(TenantsMap::Initializing));

@@ -592,11 +570,7 @@ pub async fn init_tenant_mgr(
    );
    TENANT.startup_scheduled.inc_by(tenant_configs.len() as u64);

-    // Accumulate futures for writing tenant configs, so that we can execute in parallel
-    let mut config_write_futs = Vec::new();
-
-    // Update the location configs according to the re-attach response and persist them to disk
-    tracing::info!("Updating {} location configs", tenant_configs.len());
+    // Construct `Tenant` objects and start them running
    for (tenant_shard_id, location_conf) in tenant_configs {
        let tenant_dir_path = conf.tenant_path(&tenant_shard_id);

@@ -623,22 +597,18 @@ pub async fn init_tenant_mgr(
        const DEFAULT_SECONDARY_CONF: SecondaryLocationConfig =
            SecondaryLocationConfig { warm: true };

+        // Update the location config according to the re-attach response
        if let Some(tenant_modes) = &tenant_modes {
            // We have a generation map: treat it as the authority for whether
            // this tenant is really attached.
            match tenant_modes.get(&tenant_shard_id) {
                None => {
                    info!(tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(), "Detaching tenant, control plane omitted it in re-attach response");
-
-                    match safe_rename_tenant_dir(&tenant_dir_path).await {
-                        Ok(tmp_path) => {
-                            spawn_background_purge(tmp_path);
-                        }
-                        Err(e) => {
-                            error!(tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(),
-                            "Failed to move detached tenant directory '{tenant_dir_path}': {e:?}");
-                        }
-                    };
+                    if let Err(e) = safe_remove_tenant_dir_all(&tenant_dir_path).await {
+                        error!(tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(),
+                            "Failed to remove detached tenant directory '{tenant_dir_path}': {e:?}",
+                        );
+                    }

                    // We deleted local content: move on to next tenant, don't try and spawn this one.
                    continue;
@@ -684,32 +654,8 @@ pub async fn init_tenant_mgr(

        // Presence of a generation number implies attachment: attach the tenant
        // if it wasn't already, and apply the generation number.
-        config_write_futs.push(async move {
-            let r = Tenant::persist_tenant_config(conf, &tenant_shard_id, &location_conf).await;
-            (tenant_shard_id, location_conf, r)
-        });
-    }
+        Tenant::persist_tenant_config(conf, &tenant_shard_id, &location_conf).await?;

-    // Execute config writes with concurrency, to avoid bottlenecking on local FS write latency
-    tracing::info!(
-        "Writing {} location config files...",
-        config_write_futs.len()
-    );
-    let config_write_results = futures::stream::iter(config_write_futs)
-        .buffer_unordered(16)
-        .collect::<Vec<_>>()
-        .await;
-
-    tracing::info!(
-        "Spawning {} tenant shard locations...",
-        config_write_results.len()
-    );
-    // For those shards that have live configurations, construct `Tenant` or `SecondaryTenant` objects and start them running
-    for (tenant_shard_id, location_conf, config_write_result) in config_write_results {
-        // Errors writing configs are fatal
-        config_write_result?;
-
-        let tenant_dir_path = conf.tenant_path(&tenant_shard_id);
        let shard_identity = location_conf.shard;
        let slot = match location_conf.mode {
            LocationMode::Attached(attached_conf) => {
@@ -747,7 +693,6 @@ pub async fn init_tenant_mgr(
            }
        };

-        METRICS.slot_inserted(&slot);
        tenants.insert(tenant_shard_id, slot);
    }

@@ -755,7 +700,7 @@ pub async fn init_tenant_mgr(

    let mut tenants_map = TENANTS.write().unwrap();
    assert!(matches!(&*tenants_map, &TenantsMap::Initializing));
-
+    METRICS.tenant_slots.set(tenants.len() as u64);
    *tenants_map = TenantsMap::Open(tenants);

    Ok(TenantManager {
@@ -826,14 +771,6 @@ fn tenant_spawn(
 async fn shutdown_all_tenants0(tenants: &std::sync::RwLock<TenantsMap>) {
    let mut join_set = JoinSet::new();

-    #[cfg(all(debug_assertions, not(test)))]
-    {
-        // Check that our metrics properly tracked the size of the tenants map.  This is a convenient location to check,
-        // as it happens implicitly at the end of tests etc.
-        let m = tenants.read().unwrap();
-        debug_assert_eq!(METRICS.slots_total(), m.len() as u64);
-    }
-
    // Atomically, 1. create the shutdown tasks and 2. prevent creation of new tenants.
    let (total_in_progress, total_attached) = {
        let mut m = tenants.write().unwrap();
@@ -1762,7 +1699,7 @@ impl TenantManager {
        let tmp_path = safe_rename_tenant_dir(&local_tenant_directory)
            .await
            .with_context(|| format!("local tenant directory {local_tenant_directory:?} rename"))?;
-        spawn_background_purge(tmp_path);
+        self.spawn_background_purge(tmp_path);

        fail::fail_point!("shard-split-pre-finish", |_| Err(anyhow::anyhow!(
            "failpoint"
@@ -1917,6 +1854,28 @@ impl TenantManager {
        shutdown_all_tenants0(self.tenants).await
    }

+    /// When we have moved a tenant's content to a temporary directory, we may delete it lazily in
+    /// the background, and thereby avoid blocking any API requests on this deletion completing.
+    fn spawn_background_purge(&self, tmp_path: Utf8PathBuf) {
+        // Although we are cleaning up the tenant, this task is not meant to be bound by the lifetime of the tenant in memory.
+        // After a tenant is detached, there are no more task_mgr tasks for that tenant_id.
+        let task_tenant_id = None;
+
+        task_mgr::spawn(
+            task_mgr::BACKGROUND_RUNTIME.handle(),
+            TaskKind::MgmtRequest,
+            task_tenant_id,
+            None,
+            "tenant_files_delete",
+            false,
+            async move {
+                fs::remove_dir_all(tmp_path.as_path())
+                    .await
+                    .with_context(|| format!("tenant directory {:?} deletion", tmp_path))
+            },
+        );
+    }
+
    pub(crate) async fn detach_tenant(
        &self,
        conf: &'static PageServerConf,
@@ -1933,7 +1892,7 @@ impl TenantManager {
                deletion_queue_client,
            )
            .await?;
-        spawn_background_purge(tmp_path);
+        self.spawn_background_purge(tmp_path);

        Ok(())
    }
@@ -2438,13 +2397,10 @@ impl SlotGuard {
                TenantsMap::Open(m) => m,
            };

-            METRICS.slot_inserted(&new_value);
-
            let replaced = m.insert(self.tenant_shard_id, new_value);
            self.upserted = true;
-            if let Some(replaced) = replaced.as_ref() {
-                METRICS.slot_removed(replaced);
-            }
+
+            METRICS.tenant_slots.set(m.len() as u64);

            replaced
        };
@@ -2554,13 +2510,9 @@ impl Drop for SlotGuard {
                }

                if self.old_value_is_shutdown() {
-                    METRICS.slot_removed(entry.get());
                    entry.remove();
                } else {
-                    let inserting = self.old_value.take().unwrap();
-                    METRICS.slot_inserted(&inserting);
-                    let replaced = entry.insert(inserting);
-                    METRICS.slot_removed(&replaced);
+                    entry.insert(self.old_value.take().unwrap());
                }
            }
            Entry::Vacant(_) => {
@@ -2571,6 +2523,8 @@ impl Drop for SlotGuard {
                );
            }
        }
+
+        METRICS.tenant_slots.set(m.len() as u64);
    }
 }

@@ -2650,9 +2604,7 @@ fn tenant_map_acquire_slot_impl(
            }
            _ => {
                let (completion, barrier) = utils::completion::channel();
-                let inserting = TenantSlot::InProgress(barrier);
-                METRICS.slot_inserted(&inserting);
-                v.insert(inserting);
+                v.insert(TenantSlot::InProgress(barrier));
                tracing::debug!("Vacant, inserted InProgress");
                Ok(SlotGuard::new(*tenant_shard_id, None, completion))
            }
@@ -2688,10 +2640,7 @@ fn tenant_map_acquire_slot_impl(
                _ => {
                    // Happy case: the slot was not in any state that violated our mode
                    let (completion, barrier) = utils::completion::channel();
-                    let in_progress = TenantSlot::InProgress(barrier);
-                    METRICS.slot_inserted(&in_progress);
-                    let old_value = o.insert(in_progress);
-                    METRICS.slot_removed(&old_value);
+                    let old_value = o.insert(TenantSlot::InProgress(barrier));
                    tracing::debug!("Occupied, replaced with InProgress");
                    Ok(SlotGuard::new(
                        *tenant_shard_id,
--- a/pageserver/src/tenant/remote_timeline_client.rs
+++ b/pageserver/src/tenant/remote_timeline_client.rs
@@ -210,7 +210,6 @@ use tracing::{debug, error, info, instrument, warn};
 use tracing::{info_span, Instrument};
 use utils::lsn::Lsn;

-use crate::context::RequestContext;
 use crate::deletion_queue::{DeletionQueueClient, DeletionQueueError};
 use crate::metrics::{
    MeasureRemoteOp, RemoteOpFileKind, RemoteOpKind, RemoteTimelineClientMetrics,
@@ -244,9 +243,7 @@ use super::storage_layer::{Layer, LayerFileName, ResidentLayer};
 use super::upload_queue::SetDeletedFlagProgress;
 use super::Generation;

-pub(crate) use download::{
-    download_index_part, is_temp_download_file, list_remote_tenant_shards, list_remote_timelines,
-};
+pub(crate) use download::{is_temp_download_file, list_remote_timelines};
 pub(crate) use index::LayerFileMetadata;

 // Occasional network issues and such can cause remote operations to fail, and
@@ -475,7 +472,7 @@ impl RemoteTimelineClient {
            },
        );

-        let (index_part, _index_generation) = download::download_index_part(
+        let index_part = download::download_index_part(
            &self.storage_impl,
            &self.tenant_shard_id,
            &self.timeline_id,
@@ -506,7 +503,6 @@ impl RemoteTimelineClient {
        layer_file_name: &LayerFileName,
        layer_metadata: &LayerFileMetadata,
        cancel: &CancellationToken,
-        ctx: &RequestContext,
    ) -> anyhow::Result<u64> {
        let downloaded_size = {
            let _unfinished_gauge_guard = self.metrics.call_begin(
@@ -524,7 +520,6 @@ impl RemoteTimelineClient {
                layer_file_name,
                layer_metadata,
                cancel,
-                ctx,
            )
            .measure_remote_op(
                RemoteOpFileKind::Layer,
@@ -1721,11 +1716,6 @@ impl RemoteTimelineClient {
    }
 }

-pub fn remote_tenant_path(tenant_shard_id: &TenantShardId) -> RemotePath {
-    let path = format!("tenants/{tenant_shard_id}");
-    RemotePath::from_string(&path).expect("Failed to construct path")
-}
-
 pub fn remote_timelines_path(tenant_shard_id: &TenantShardId) -> RemotePath {
    let path = format!("tenants/{tenant_shard_id}/{TIMELINES_SEGMENT_NAME}");
    RemotePath::from_string(&path).expect("Failed to construct path")
--- a/pageserver/src/tenant/remote_timeline_client/download.rs
+++ b/pageserver/src/tenant/remote_timeline_client/download.rs
@@ -5,7 +5,6 @@

 use std::collections::HashSet;
 use std::future::Future;
-use std::str::FromStr;

 use anyhow::{anyhow, Context};
 use camino::{Utf8Path, Utf8PathBuf};
@@ -18,7 +17,6 @@ use tracing::warn;
 use utils::backoff;

 use crate::config::PageServerConf;
-use crate::context::RequestContext;
 use crate::span::debug_assert_current_span_has_tenant_and_timeline_id;
 use crate::tenant::remote_timeline_client::{remote_layer_path, remote_timelines_path};
 use crate::tenant::storage_layer::LayerFileName;
@@ -27,13 +25,13 @@ use crate::virtual_file::{on_fatal_io_error, MaybeFatalIo, VirtualFile};
 use crate::TEMP_FILE_SUFFIX;
 use remote_storage::{DownloadError, GenericRemoteStorage, ListingMode, RemotePath};
 use utils::crashsafe::path_with_suffix_extension;
-use utils::id::{TenantId, TimelineId};
+use utils::id::TimelineId;

 use super::index::{IndexPart, LayerFileMetadata};
 use super::{
    parse_remote_index_path, remote_index_path, remote_initdb_archive_path,
-    remote_initdb_preserved_archive_path, remote_tenant_path, FAILED_DOWNLOAD_WARN_THRESHOLD,
-    FAILED_REMOTE_OP_RETRIES, INITDB_PATH,
+    remote_initdb_preserved_archive_path, FAILED_DOWNLOAD_WARN_THRESHOLD, FAILED_REMOTE_OP_RETRIES,
+    INITDB_PATH,
 };

 ///
@@ -41,7 +39,6 @@ use super::{
 /// in the metadata. (In the future, we might do more cross-checks, like CRC validation)
 ///
 /// Returns the size of the downloaded file.
-#[allow(clippy::too_many_arguments)]
 pub async fn download_layer_file<'a>(
    conf: &'static PageServerConf,
    storage: &'a GenericRemoteStorage,
@@ -50,7 +47,6 @@ pub async fn download_layer_file<'a>(
    layer_file_name: &'a LayerFileName,
    layer_metadata: &'a LayerFileMetadata,
    cancel: &CancellationToken,
-    ctx: &RequestContext,
 ) -> Result<u64, DownloadError> {
    debug_assert_current_span_has_tenant_and_timeline_id();

@@ -78,7 +74,7 @@ pub async fn download_layer_file<'a>(
    let temp_file_path = path_with_suffix_extension(&local_path, TEMP_DOWNLOAD_EXTENSION);

    let bytes_amount = download_retry(
-        || async { download_object(storage, &remote_path, &temp_file_path, cancel, ctx).await },
+        || async { download_object(storage, &remote_path, &temp_file_path, cancel).await },
        &format!("download {remote_path:?}"),
        cancel,
    )
@@ -136,7 +132,6 @@ async fn download_object<'a>(
    src_path: &RemotePath,
    dst_path: &Utf8PathBuf,
    cancel: &CancellationToken,
-    #[cfg_attr(target_os = "macos", allow(unused_variables))] ctx: &RequestContext,
 ) -> Result<u64, DownloadError> {
    let res = match crate::virtual_file::io_engine::get() {
        crate::virtual_file::io_engine::IoEngine::NotSet => panic!("unset"),
@@ -187,7 +182,6 @@ async fn download_object<'a>(
        #[cfg(target_os = "linux")]
        crate::virtual_file::io_engine::IoEngine::TokioEpollUring => {
            use crate::virtual_file::owned_buffers_io::{self, util::size_tracking_writer};
-            use bytes::BytesMut;
            async {
                let destination_file = VirtualFile::create(dst_path)
                    .await
@@ -200,10 +194,10 @@ async fn download_object<'a>(
                // There's chunks_vectored() on the stream.
                let (bytes_amount, destination_file) = async {
                    let size_tracking = size_tracking_writer::Writer::new(destination_file);
-                    let mut buffered = owned_buffers_io::write::BufferedWriter::<BytesMut, _>::new(
-                        size_tracking,
-                        BytesMut::with_capacity(super::BUFFER_SIZE),
-                    );
+                    let mut buffered = owned_buffers_io::write::BufferedWriter::<
+                        { super::BUFFER_SIZE },
+                        _,
+                    >::new(size_tracking);
                    while let Some(res) =
                        futures::StreamExt::next(&mut download.download_stream).await
                    {
@@ -212,10 +206,10 @@ async fn download_object<'a>(
                            Err(e) => return Err(e),
                        };
                        buffered
-                            .write_buffered(tokio_epoll_uring::BoundedBuf::slice_full(chunk), ctx)
+                            .write_buffered(tokio_epoll_uring::BoundedBuf::slice_full(chunk))
                            .await?;
                    }
-                    let size_tracking = buffered.flush_and_into_inner(ctx).await?;
+                    let size_tracking = buffered.flush_and_into_inner().await?;
                    Ok(size_tracking.into_inner())
                }
                .await?;
@@ -258,31 +252,42 @@ pub(crate) fn is_temp_download_file(path: &Utf8Path) -> bool {
    }
 }

-async fn list_identifiers<T>(
+/// List timelines of given tenant in remote storage
+pub async fn list_remote_timelines(
    storage: &GenericRemoteStorage,
-    prefix: RemotePath,
+    tenant_shard_id: TenantShardId,
    cancel: CancellationToken,
-) -> anyhow::Result<(HashSet<T>, HashSet<String>)>
-where
-    T: FromStr + Eq + std::hash::Hash,
-{
+) -> anyhow::Result<(HashSet<TimelineId>, HashSet<String>)> {
+    let remote_path = remote_timelines_path(&tenant_shard_id).add_trailing_slash();
+
+    fail::fail_point!("storage-sync-list-remote-timelines", |_| {
+        anyhow::bail!("storage-sync-list-remote-timelines");
+    });
+
    let listing = download_retry_forever(
-        || storage.list(Some(&prefix), ListingMode::WithDelimiter, None, &cancel),
-        &format!("list identifiers in prefix {prefix}"),
+        || {
+            storage.list(
+                Some(&remote_path),
+                ListingMode::WithDelimiter,
+                None,
+                &cancel,
+            )
+        },
+        &format!("list timelines for {tenant_shard_id}"),
        &cancel,
    )
    .await?;

-    let mut parsed_ids = HashSet::new();
+    let mut timeline_ids = HashSet::new();
    let mut other_prefixes = HashSet::new();

-    for id_remote_storage_key in listing.prefixes {
-        let object_name = id_remote_storage_key.object_name().ok_or_else(|| {
-            anyhow::anyhow!("failed to get object name for key {id_remote_storage_key}")
+    for timeline_remote_storage_key in listing.prefixes {
+        let object_name = timeline_remote_storage_key.object_name().ok_or_else(|| {
+            anyhow::anyhow!("failed to get timeline id for remote tenant {tenant_shard_id}")
        })?;

-        match object_name.parse::<T>() {
-            Ok(t) => parsed_ids.insert(t),
+        match object_name.parse::<TimelineId>() {
+            Ok(t) => timeline_ids.insert(t),
            Err(_) => other_prefixes.insert(object_name.to_string()),
        };
    }
@@ -294,31 +299,7 @@ where
        other_prefixes.insert(object_name.to_string());
    }

-    Ok((parsed_ids, other_prefixes))
-}
-
-/// List shards of given tenant in remote storage
-pub(crate) async fn list_remote_tenant_shards(
-    storage: &GenericRemoteStorage,
-    tenant_id: TenantId,
-    cancel: CancellationToken,
-) -> anyhow::Result<(HashSet<TenantShardId>, HashSet<String>)> {
-    let remote_path = remote_tenant_path(&TenantShardId::unsharded(tenant_id));
-    list_identifiers::<TenantShardId>(storage, remote_path, cancel).await
-}
-
-/// List timelines of given tenant shard in remote storage
-pub async fn list_remote_timelines(
-    storage: &GenericRemoteStorage,
-    tenant_shard_id: TenantShardId,
-    cancel: CancellationToken,
-) -> anyhow::Result<(HashSet<TimelineId>, HashSet<String>)> {
-    fail::fail_point!("storage-sync-list-remote-timelines", |_| {
-        anyhow::bail!("storage-sync-list-remote-timelines");
-    });
-
-    let remote_path = remote_timelines_path(&tenant_shard_id).add_trailing_slash();
-    list_identifiers::<TimelineId>(storage, remote_path, cancel).await
+    Ok((timeline_ids, other_prefixes))
 }

 async fn do_download_index_part(
@@ -327,7 +308,7 @@ async fn do_download_index_part(
    timeline_id: &TimelineId,
    index_generation: Generation,
    cancel: &CancellationToken,
-) -> Result<(IndexPart, Generation), DownloadError> {
+) -> Result<IndexPart, DownloadError> {
    let remote_path = remote_index_path(tenant_shard_id, timeline_id, index_generation);

    let index_part_bytes = download_retry_forever(
@@ -352,7 +333,7 @@ async fn do_download_index_part(
        .with_context(|| format!("deserialize index part file at {remote_path:?}"))
        .map_err(DownloadError::Other)?;

-    Ok((index_part, index_generation))
+    Ok(index_part)
 }

 /// index_part.json objects are suffixed with a generation number, so we cannot
@@ -361,13 +342,13 @@ async fn do_download_index_part(
 /// In this function we probe for the most recent index in a generation <= our current generation.
 /// See "Finding the remote indices for timelines" in docs/rfcs/025-generation-numbers.md
 #[tracing::instrument(skip_all, fields(generation=?my_generation))]
-pub(crate) async fn download_index_part(
+pub(super) async fn download_index_part(
    storage: &GenericRemoteStorage,
    tenant_shard_id: &TenantShardId,
    timeline_id: &TimelineId,
    my_generation: Generation,
    cancel: &CancellationToken,
-) -> Result<(IndexPart, Generation), DownloadError> {
+) -> Result<IndexPart, DownloadError> {
    debug_assert_current_span_has_tenant_and_timeline_id();

    if my_generation.is_none() {
--- a/pageserver/src/tenant/secondary.rs
+++ b/pageserver/src/tenant/secondary.rs
@@ -7,7 +7,6 @@ use std::{sync::Arc, time::SystemTime};

 use crate::{
    config::PageServerConf,
-    context::RequestContext,
    disk_usage_eviction_task::DiskUsageEvictionInfo,
    task_mgr::{self, TaskKind, BACKGROUND_RUNTIME},
    virtual_file::MaybeFatalIo,
@@ -317,13 +316,9 @@ pub fn spawn_tasks(
    let (upload_req_tx, upload_req_rx) =
        tokio::sync::mpsc::channel::<CommandRequest<UploadCommand>>(16);

-    let downloader_task_ctx = RequestContext::new(
-        TaskKind::SecondaryDownloads,
-        crate::context::DownloadBehavior::Download,
-    );
    task_mgr::spawn(
        BACKGROUND_RUNTIME.handle(),
-        downloader_task_ctx.task_kind(),
+        TaskKind::SecondaryDownloads,
        None,
        None,
        "secondary tenant downloads",
@@ -335,7 +330,6 @@ pub fn spawn_tasks(
                download_req_rx,
                bg_jobs_clone,
                cancel_clone,
-                downloader_task_ctx,
            )
            .await;

--- a/pageserver/src/tenant/secondary/downloader.rs
+++ b/pageserver/src/tenant/secondary/downloader.rs
@@ -8,7 +8,6 @@ use std::{

 use crate::{
    config::PageServerConf,
-    context::RequestContext,
    disk_usage_eviction_task::{
        finite_f32, DiskUsageEvictionInfo, EvictionCandidate, EvictionLayer, EvictionSecondaryLayer,
    },
@@ -31,10 +30,7 @@ use crate::{

 use super::{
    heatmap::HeatMapLayer,
-    scheduler::{
-        self, period_jitter, period_warmup, Completion, JobGenerator, SchedulingResult,
-        TenantBackgroundJobs,
-    },
+    scheduler::{self, Completion, JobGenerator, SchedulingResult, TenantBackgroundJobs},
    SecondaryTenant,
 };

@@ -48,6 +44,7 @@ use chrono::format::{DelayedFormat, StrftimeItems};
 use futures::Future;
 use pageserver_api::models::SecondaryProgress;
 use pageserver_api::shard::TenantShardId;
+use rand::Rng;
 use remote_storage::{DownloadError, Etag, GenericRemoteStorage};

 use tokio_util::sync::CancellationToken;
@@ -77,14 +74,12 @@ pub(super) async fn downloader_task(
    command_queue: tokio::sync::mpsc::Receiver<CommandRequest<DownloadCommand>>,
    background_jobs_can_start: Barrier,
    cancel: CancellationToken,
-    root_ctx: RequestContext,
 ) {
    let concurrency = tenant_manager.get_conf().secondary_download_concurrency;

    let generator = SecondaryDownloader {
        tenant_manager,
        remote_storage,
-        root_ctx,
    };
    let mut scheduler = Scheduler::new(generator, concurrency);

@@ -97,7 +92,6 @@ pub(super) async fn downloader_task(
 struct SecondaryDownloader {
    tenant_manager: Arc<TenantManager>,
    remote_storage: GenericRemoteStorage,
-    root_ctx: RequestContext,
 }

 #[derive(Debug, Clone)]
@@ -276,7 +270,7 @@ impl JobGenerator<PendingDownload, RunningDownload, CompleteDownload, DownloadCo
        // Update freshened_at even if there was an error: we don't want errored tenants to implicitly
        // take priority to run again.
        let mut detail = secondary_state.detail.lock().unwrap();
-        detail.next_download = Some(Instant::now() + period_jitter(DOWNLOAD_FRESHEN_INTERVAL, 5));
+        detail.next_download = Some(Instant::now() + DOWNLOAD_FRESHEN_INTERVAL);
    }

    async fn schedule(&mut self) -> SchedulingResult<PendingDownload> {
@@ -307,9 +301,11 @@ impl JobGenerator<PendingDownload, RunningDownload, CompleteDownload, DownloadCo
                    }

                    if detail.next_download.is_none() {
-                        // Initialize randomly in the range from 0 to our interval: this uniformly spreads the start times.  Subsequent
-                        // rounds will use a smaller jitter to avoid accidentally synchronizing later.
-                        detail.next_download = Some(now.checked_add(period_warmup(DOWNLOAD_FRESHEN_INTERVAL)).expect(
+                        // Initialize with a jitter: this spreads initial downloads on startup
+                        // or mass-attach across our freshen interval.
+                        let jittered_period =
+                            rand::thread_rng().gen_range(Duration::ZERO..DOWNLOAD_FRESHEN_INTERVAL);
+                        detail.next_download = Some(now.checked_add(jittered_period).expect(
                        "Using our constant, which is known to be small compared with clock range",
                    ));
                    }
@@ -371,12 +367,11 @@ impl JobGenerator<PendingDownload, RunningDownload, CompleteDownload, DownloadCo
        let remote_storage = self.remote_storage.clone();
        let conf = self.tenant_manager.get_conf();
        let tenant_shard_id = *secondary_state.get_tenant_shard_id();
-        let download_ctx = self.root_ctx.attached_child();
        (RunningDownload { barrier }, Box::pin(async move {
            let _completion = completion;

            match TenantDownloader::new(conf, &remote_storage, &secondary_state)
-                .download(&download_ctx)
+                .download()
                .await
            {
                Err(UpdateError::NoData) => {
@@ -490,7 +485,7 @@ impl<'a> TenantDownloader<'a> {
        }
    }

-    async fn download(&self, ctx: &RequestContext) -> Result<(), UpdateError> {
+    async fn download(&self) -> Result<(), UpdateError> {
        debug_assert_current_span_has_tenant_id();

        // For the duration of a download, we must hold the SecondaryTenant::gate, to ensure
@@ -565,7 +560,7 @@ impl<'a> TenantDownloader<'a> {
            }

            let timeline_id = timeline.timeline_id;
-            self.download_timeline(timeline, ctx)
+            self.download_timeline(timeline)
                .instrument(tracing::info_span!(
                    "secondary_download_timeline",
                    tenant_id=%tenant_shard_id.tenant_id,
@@ -747,11 +742,7 @@ impl<'a> TenantDownloader<'a> {
        .and_then(|x| x)
    }

-    async fn download_timeline(
-        &self,
-        timeline: HeatMapTimeline,
-        ctx: &RequestContext,
-    ) -> Result<(), UpdateError> {
+    async fn download_timeline(&self, timeline: HeatMapTimeline) -> Result<(), UpdateError> {
        debug_assert_current_span_has_tenant_and_timeline_id();
        let tenant_shard_id = self.secondary_state.get_tenant_shard_id();
        let timeline_path = self
@@ -884,7 +875,6 @@ impl<'a> TenantDownloader<'a> {
                &layer.name,
                &LayerFileMetadata::from(&layer.metadata),
                &self.secondary_state.cancel,
-                ctx,
            )
            .await
            {
--- a/pageserver/src/tenant/secondary/heatmap_uploader.rs
+++ b/pageserver/src/tenant/secondary/heatmap_uploader.rs
@@ -20,14 +20,12 @@ use crate::{

 use futures::Future;
 use pageserver_api::shard::TenantShardId;
+use rand::Rng;
 use remote_storage::{GenericRemoteStorage, TimeoutOrCancel};

 use super::{
    heatmap::HeatMapTenant,
-    scheduler::{
-        self, period_jitter, period_warmup, JobGenerator, RunningJob, SchedulingResult,
-        TenantBackgroundJobs,
-    },
+    scheduler::{self, JobGenerator, RunningJob, SchedulingResult, TenantBackgroundJobs},
    CommandRequest, UploadCommand,
 };
 use tokio_util::sync::CancellationToken;
@@ -183,11 +181,15 @@ impl JobGenerator<UploadPending, WriteInProgress, WriteComplete, UploadCommand>
            let state = self
                .tenants
                .entry(*tenant.get_tenant_shard_id())
-                .or_insert_with(|| UploaderTenantState {
-                    tenant: Arc::downgrade(&tenant),
-                    last_upload: None,
-                    next_upload: Some(now.checked_add(period_warmup(period)).unwrap_or(now)),
-                    last_digest: None,
+                .or_insert_with(|| {
+                    let jittered_period = rand::thread_rng().gen_range(Duration::ZERO..period);
+
+                    UploaderTenantState {
+                        tenant: Arc::downgrade(&tenant),
+                        last_upload: None,
+                        next_upload: Some(now.checked_add(jittered_period).unwrap_or(now)),
+                        last_digest: None,
+                    }
                });

            // Decline to do the upload if insufficient time has passed
@@ -272,7 +274,7 @@ impl JobGenerator<UploadPending, WriteInProgress, WriteComplete, UploadCommand>

            let next_upload = tenant
                .get_heatmap_period()
-                .and_then(|period| now.checked_add(period_jitter(period, 5)));
+                .and_then(|period| now.checked_add(period));

            WriteComplete {
                    tenant_shard_id: *tenant.get_tenant_shard_id(),
--- a/pageserver/src/tenant/secondary/scheduler.rs
+++ b/pageserver/src/tenant/secondary/scheduler.rs
@@ -1,5 +1,4 @@
 use futures::Future;
-use rand::Rng;
 use std::{
    collections::HashMap,
    marker::PhantomData,
@@ -20,26 +19,6 @@ use super::{CommandRequest, CommandResponse};
 const MAX_SCHEDULING_INTERVAL: Duration = Duration::from_secs(10);
 const MIN_SCHEDULING_INTERVAL: Duration = Duration::from_secs(1);

-/// Jitter a Duration by an integer percentage.  Returned values are uniform
-/// in the range 100-pct..100+pct (i.e. a 5% jitter is 5% either way: a ~10% range)
-pub(super) fn period_jitter(d: Duration, pct: u32) -> Duration {
-    if d == Duration::ZERO {
-        d
-    } else {
-        rand::thread_rng().gen_range((d * (100 - pct)) / 100..(d * (100 + pct)) / 100)
-    }
-}
-
-/// When a periodic task first starts, it should wait for some time in the range 0..period, so
-/// that starting many such tasks at the same time spreads them across the time range.
-pub(super) fn period_warmup(period: Duration) -> Duration {
-    if period == Duration::ZERO {
-        period
-    } else {
-        rand::thread_rng().gen_range(Duration::ZERO..period)
-    }
-}
-
 /// Scheduling helper for background work across many tenants.
 ///
 /// Systems that need to run background work across many tenants may use this type
--- a/pageserver/src/tenant/size.rs
+++ b/pageserver/src/tenant/size.rs
@@ -189,9 +189,7 @@ pub(super) async fn gather_inputs(
        // than a space bound (horizon cutoff).  This means that if someone drops a database and waits for their
        // PITR interval, they will see synthetic size decrease, even if we are still storing data inside
        // horizon_cutoff.
-        let pitr_cutoff = gc_info.cutoffs.pitr;
-        let horizon_cutoff = gc_info.cutoffs.horizon;
-        let mut next_gc_cutoff = pitr_cutoff;
+        let mut next_gc_cutoff = gc_info.pitr_cutoff;

        // If the caller provided a shorter retention period, use that instead of the GC cutoff.
        let retention_param_cutoff = if let Some(max_retention_period) = max_retention_period {
@@ -218,8 +216,6 @@ pub(super) async fn gather_inputs(
            .map(|lsn| (lsn, LsnKind::BranchPoint))
            .collect::<Vec<_>>();

-        drop(gc_info);
-
        // Add branch points we collected earlier, just in case there were any that were
        // not present in retain_lsns. We will remove any duplicates below later.
        if let Some(this_branchpoints) = branchpoints.get(&timeline_id) {
@@ -298,8 +294,8 @@ pub(super) async fn gather_inputs(
            last_record: last_record_lsn,
            // this is not used above, because it might not have updated recently enough
            latest_gc_cutoff: *timeline.get_latest_gc_cutoff_lsn(),
-            horizon_cutoff,
-            pitr_cutoff,
+            horizon_cutoff: gc_info.horizon_cutoff,
+            pitr_cutoff: gc_info.pitr_cutoff,
            next_gc_cutoff,
            retention_param_cutoff,
        });
--- a/pageserver/src/tenant/storage_layer/delta_layer.rs
+++ b/pageserver/src/tenant/storage_layer/delta_layer.rs
@@ -428,15 +428,9 @@ impl DeltaLayerWriterInner {
    ///
    /// The values must be appended in key, lsn order.
    ///
-    async fn put_value(
-        &mut self,
-        key: Key,
-        lsn: Lsn,
-        val: Value,
-        ctx: &RequestContext,
-    ) -> anyhow::Result<()> {
+    async fn put_value(&mut self, key: Key, lsn: Lsn, val: Value) -> anyhow::Result<()> {
        let (_, res) = self
-            .put_value_bytes(key, lsn, Value::ser(&val)?, val.will_init(), ctx)
+            .put_value_bytes(key, lsn, Value::ser(&val)?, val.will_init())
            .await;
        res
    }
@@ -447,10 +441,9 @@ impl DeltaLayerWriterInner {
        lsn: Lsn,
        val: Vec<u8>,
        will_init: bool,
-        ctx: &RequestContext,
    ) -> (Vec<u8>, anyhow::Result<()>) {
        assert!(self.lsn_range.start <= lsn);
-        let (val, res) = self.blob_writer.write_blob(val, ctx).await;
+        let (val, res) = self.blob_writer.write_blob(val).await;
        let off = match res {
            Ok(off) => off,
            Err(e) => return (val, Err(anyhow::anyhow!(e))),
@@ -470,23 +463,18 @@ impl DeltaLayerWriterInner {
    ///
    /// Finish writing the delta layer.
    ///
-    async fn finish(
-        self,
-        key_end: Key,
-        timeline: &Arc<Timeline>,
-        ctx: &RequestContext,
-    ) -> anyhow::Result<ResidentLayer> {
+    async fn finish(self, key_end: Key, timeline: &Arc<Timeline>) -> anyhow::Result<ResidentLayer> {
        let index_start_blk =
            ((self.blob_writer.size() + PAGE_SZ as u64 - 1) / PAGE_SZ as u64) as u32;

-        let mut file = self.blob_writer.into_inner(ctx).await?;
+        let mut file = self.blob_writer.into_inner().await?;

        // Write out the index
        let (index_root_blk, block_buf) = self.tree.finish()?;
        file.seek(SeekFrom::Start(index_start_blk as u64 * PAGE_SZ as u64))
            .await?;
        for buf in block_buf.blocks {
-            let (_buf, res) = file.write_all(buf, ctx).await;
+            let (_buf, res) = file.write_all(buf).await;
            res?;
        }
        assert!(self.lsn_range.start < self.lsn_range.end);
@@ -506,7 +494,7 @@ impl DeltaLayerWriterInner {
        // TODO: could use smallvec here but it's a pain with Slice<T>
        Summary::ser_into(&summary, &mut buf)?;
        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf, ctx).await;
+        let (_buf, res) = file.write_all(buf).await;
        res?;

        let metadata = file
@@ -604,18 +592,8 @@ impl DeltaLayerWriter {
    ///
    /// The values must be appended in key, lsn order.
    ///
-    pub async fn put_value(
-        &mut self,
-        key: Key,
-        lsn: Lsn,
-        val: Value,
-        ctx: &RequestContext,
-    ) -> anyhow::Result<()> {
-        self.inner
-            .as_mut()
-            .unwrap()
-            .put_value(key, lsn, val, ctx)
-            .await
+    pub async fn put_value(&mut self, key: Key, lsn: Lsn, val: Value) -> anyhow::Result<()> {
+        self.inner.as_mut().unwrap().put_value(key, lsn, val).await
    }

    pub async fn put_value_bytes(
@@ -624,12 +602,11 @@ impl DeltaLayerWriter {
        lsn: Lsn,
        val: Vec<u8>,
        will_init: bool,
-        ctx: &RequestContext,
    ) -> (Vec<u8>, anyhow::Result<()>) {
        self.inner
            .as_mut()
            .unwrap()
-            .put_value_bytes(key, lsn, val, will_init, ctx)
+            .put_value_bytes(key, lsn, val, will_init)
            .await
    }

@@ -644,11 +621,10 @@ impl DeltaLayerWriter {
        mut self,
        key_end: Key,
        timeline: &Arc<Timeline>,
-        ctx: &RequestContext,
    ) -> anyhow::Result<ResidentLayer> {
        let inner = self.inner.take().unwrap();
        let temp_path = inner.path.clone();
-        let result = inner.finish(key_end, timeline, ctx).await;
+        let result = inner.finish(key_end, timeline).await;
        // The delta layer files can sometimes be really large. Clean them up.
        if result.is_err() {
            tracing::warn!(
@@ -716,7 +692,7 @@ impl DeltaLayer {
        // TODO: could use smallvec here, but it's a pain with Slice<T>
        Summary::ser_into(&new_summary, &mut buf).context("serialize")?;
        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf, ctx).await;
+        let (_buf, res) = file.write_all(buf).await;
        res?;
        Ok(())
    }
@@ -1305,13 +1281,7 @@ impl DeltaLayerInner {
                    per_blob_copy.extend_from_slice(data);

                    let (tmp, res) = writer
-                        .put_value_bytes(
-                            key,
-                            lsn,
-                            std::mem::take(&mut per_blob_copy),
-                            will_init,
-                            ctx,
-                        )
+                        .put_value_bytes(key, lsn, std::mem::take(&mut per_blob_copy), will_init)
                        .await;
                    per_blob_copy = tmp;
                    res?;
@@ -1790,14 +1760,12 @@ mod test {

        for entry in entries {
            let (_, res) = writer
-                .put_value_bytes(entry.key, entry.lsn, entry.value, false, &ctx)
+                .put_value_bytes(entry.key, entry.lsn, entry.value, false)
                .await;
            res?;
        }

-        let resident = writer
-            .finish(entries_meta.key_range.end, &timeline, &ctx)
-            .await?;
+        let resident = writer.finish(entries_meta.key_range.end, &timeline).await?;

        let inner = resident.as_delta(&ctx).await?;

@@ -1983,7 +1951,7 @@ mod test {
                .await
                .unwrap();

-            let copied_layer = writer.finish(Key::MAX, &branch, ctx).await.unwrap();
+            let copied_layer = writer.finish(Key::MAX, &branch).await.unwrap();

            copied_layer.as_delta(ctx).await.unwrap();

--- a/pageserver/src/tenant/storage_layer/image_layer.rs
+++ b/pageserver/src/tenant/storage_layer/image_layer.rs
@@ -357,7 +357,7 @@ impl ImageLayer {
        // TODO: could use smallvec here but it's a pain with Slice<T>
        Summary::ser_into(&new_summary, &mut buf).context("serialize")?;
        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf, ctx).await;
+        let (_buf, res) = file.write_all(buf).await;
        res?;
        Ok(())
    }
@@ -677,14 +677,9 @@ impl ImageLayerWriterInner {
    ///
    /// The page versions must be appended in blknum order.
    ///
-    async fn put_image(
-        &mut self,
-        key: Key,
-        img: Bytes,
-        ctx: &RequestContext,
-    ) -> anyhow::Result<()> {
+    async fn put_image(&mut self, key: Key, img: Bytes) -> anyhow::Result<()> {
        ensure!(self.key_range.contains(&key));
-        let (_img, res) = self.blob_writer.write_blob(img, ctx).await;
+        let (_img, res) = self.blob_writer.write_blob(img).await;
        // TODO: re-use the buffer for `img` further upstack
        let off = res?;

@@ -698,11 +693,7 @@ impl ImageLayerWriterInner {
    ///
    /// Finish writing the image layer.
    ///
-    async fn finish(
-        self,
-        timeline: &Arc<Timeline>,
-        ctx: &RequestContext,
-    ) -> anyhow::Result<ResidentLayer> {
+    async fn finish(self, timeline: &Arc<Timeline>) -> anyhow::Result<ResidentLayer> {
        let index_start_blk =
            ((self.blob_writer.size() + PAGE_SZ as u64 - 1) / PAGE_SZ as u64) as u32;

@@ -713,7 +704,7 @@ impl ImageLayerWriterInner {
            .await?;
        let (index_root_blk, block_buf) = self.tree.finish()?;
        for buf in block_buf.blocks {
-            let (_buf, res) = file.write_all(buf, ctx).await;
+            let (_buf, res) = file.write_all(buf).await;
            res?;
        }

@@ -733,7 +724,7 @@ impl ImageLayerWriterInner {
        // TODO: could use smallvec here but it's a pain with Slice<T>
        Summary::ser_into(&summary, &mut buf)?;
        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf, ctx).await;
+        let (_buf, res) = file.write_all(buf).await;
        res?;

        let metadata = file
@@ -815,13 +806,8 @@ impl ImageLayerWriter {
    ///
    /// The page versions must be appended in blknum order.
    ///
-    pub async fn put_image(
-        &mut self,
-        key: Key,
-        img: Bytes,
-        ctx: &RequestContext,
-    ) -> anyhow::Result<()> {
-        self.inner.as_mut().unwrap().put_image(key, img, ctx).await
+    pub async fn put_image(&mut self, key: Key, img: Bytes) -> anyhow::Result<()> {
+        self.inner.as_mut().unwrap().put_image(key, img).await
    }

    ///
@@ -830,9 +816,8 @@ impl ImageLayerWriter {
    pub(crate) async fn finish(
        mut self,
        timeline: &Arc<Timeline>,
-        ctx: &RequestContext,
    ) -> anyhow::Result<super::ResidentLayer> {
-        self.inner.take().unwrap().finish(timeline, ctx).await
+        self.inner.take().unwrap().finish(timeline).await
    }
 }

--- a/pageserver/src/tenant/storage_layer/inmemory_layer.rs
+++ b/pageserver/src/tenant/storage_layer/inmemory_layer.rs
@@ -17,7 +17,7 @@ use anyhow::{anyhow, ensure, Result};
 use pageserver_api::keyspace::KeySpace;
 use pageserver_api::models::InMemoryLayerInfo;
 use pageserver_api::shard::TenantShardId;
-use std::collections::{BTreeMap, BinaryHeap, HashSet};
+use std::collections::{BinaryHeap, HashMap, HashSet};
 use std::sync::{Arc, OnceLock};
 use std::time::Instant;
 use tracing::*;
@@ -78,10 +78,10 @@ impl std::fmt::Debug for InMemoryLayer {
 }

 pub struct InMemoryLayerInner {
-    /// All versions of all pages in the layer are kept here. Indexed
+    /// All versions of all pages in the layer are kept here.  Indexed
    /// by block number and LSN. The value is an offset into the
    /// ephemeral file where the page version is stored.
-    index: BTreeMap<Key, VecMap<Lsn, u64>>,
+    index: HashMap<Key, VecMap<Lsn, u64>>,

    /// The values are stored in a serialized format in this file.
    /// Each serialized Value is preceded by a 'u32' length field.
@@ -384,20 +384,25 @@ impl InMemoryLayer {
        let mut planned_block_reads = BinaryHeap::new();

        for range in keyspace.ranges.iter() {
-            for (key, vec_map) in inner.index.range(range.start..range.end) {
-                let lsn_range = match reconstruct_state.get_cached_lsn(key) {
-                    Some(cached_lsn) => (cached_lsn + 1)..end_lsn,
-                    None => self.start_lsn..end_lsn,
-                };
+            let mut key = range.start;
+            while key < range.end {
+                if let Some(vec_map) = inner.index.get(&key) {
+                    let lsn_range = match reconstruct_state.get_cached_lsn(&key) {
+                        Some(cached_lsn) => (cached_lsn + 1)..end_lsn,
+                        None => self.start_lsn..end_lsn,
+                    };

-                let slice = vec_map.slice_range(lsn_range);
-                for (entry_lsn, pos) in slice.iter().rev() {
-                    planned_block_reads.push(BlockRead {
-                        key: *key,
-                        lsn: *entry_lsn,
-                        block_offset: *pos,
-                    });
+                    let slice = vec_map.slice_range(lsn_range);
+                    for (entry_lsn, pos) in slice.iter().rev() {
+                        planned_block_reads.push(BlockRead {
+                            key,
+                            lsn: *entry_lsn,
+                            block_offset: *pos,
+                        });
+                    }
                }
+
+                key = key.next();
            }
        }

@@ -477,7 +482,7 @@ impl InMemoryLayer {
        trace!("initializing new empty InMemoryLayer for writing on timeline {timeline_id} at {start_lsn}");

        let file = EphemeralFile::create(conf, tenant_shard_id, timeline_id).await?;
-        let key = InMemoryLayerFileId(file.page_cache_file_id());
+        let key = InMemoryLayerFileId(file.id());

        Ok(InMemoryLayer {
            file_id: key,
@@ -494,7 +499,7 @@ impl InMemoryLayer {
            end_lsn: OnceLock::new(),
            opened_at: Instant::now(),
            inner: RwLock::new(InMemoryLayerInner {
-                index: BTreeMap::new(),
+                index: HashMap::new(),
                file,
                resource_units: GlobalResourceUnits::new(),
            }),
@@ -597,17 +602,14 @@ impl InMemoryLayer {
        }
    }

-    /// Write this frozen in-memory layer to disk. If `key_range` is set, the delta
-    /// layer will only contain the key range the user specifies, and may return `None`
-    /// if there are no matching keys.
+    /// Write this frozen in-memory layer to disk.
    ///
    /// Returns a new delta layer with all the same data as this in-memory layer
    pub(crate) async fn write_to_disk(
        &self,
        timeline: &Arc<Timeline>,
        ctx: &RequestContext,
-        key_range: Option<Range<Key>>,
-    ) -> Result<Option<ResidentLayer>> {
+    ) -> Result<ResidentLayer> {
        // Grab the lock in read-mode. We hold it over the I/O, but because this
        // layer is not writeable anymore, no one should be trying to acquire the
        // write lock on it, so we shouldn't block anyone. There's one exception
@@ -621,21 +623,6 @@ impl InMemoryLayer {

        let end_lsn = *self.end_lsn.get().unwrap();

-        let keys: Vec<_> = if let Some(key_range) = key_range {
-            inner
-                .index
-                .iter()
-                .filter(|(k, _)| key_range.contains(k))
-                .map(|(k, m)| (k.to_i128(), m))
-                .collect()
-        } else {
-            inner.index.iter().map(|(k, m)| (k.to_i128(), m)).collect()
-        };
-
-        if keys.is_empty() {
-            return Ok(None);
-        }
-
        let mut delta_layer_writer = DeltaLayerWriter::new(
            self.conf,
            self.timeline_id,
@@ -649,24 +636,33 @@ impl InMemoryLayer {

        let cursor = inner.file.block_cursor();

+        // Sort the keys because delta layer writer expects them sorted.
+        //
+        // NOTE: this sort can take up significant time if the layer has millions of
+        //       keys. To speed up all the comparisons we convert the key to i128 and
+        //       keep the value as a reference.
+        let mut keys: Vec<_> = inner.index.iter().map(|(k, m)| (k.to_i128(), m)).collect();
+        keys.sort_unstable_by_key(|k| k.0);
+
        let ctx = RequestContextBuilder::extend(ctx)
            .page_content_kind(PageContentKind::InMemoryLayer)
            .build();
-        for (key, vec_map) in inner.index.iter() {
+        for (key, vec_map) in keys.iter() {
+            let key = Key::from_i128(*key);
            // Write all page versions
            for (lsn, pos) in vec_map.as_slice() {
                cursor.read_blob_into_buf(*pos, &mut buf, &ctx).await?;
                let will_init = Value::des(&buf)?.will_init();
                let res;
                (buf, res) = delta_layer_writer
-                    .put_value_bytes(*key, *lsn, buf, will_init, &ctx)
+                    .put_value_bytes(key, *lsn, buf, will_init)
                    .await;
                res?;
            }
        }

        // MAX is used here because we identify L0 layers by full key range
-        let delta_layer = delta_layer_writer.finish(Key::MAX, timeline, &ctx).await?;
-        Ok(Some(delta_layer))
+        let delta_layer = delta_layer_writer.finish(Key::MAX, timeline).await?;
+        Ok(delta_layer)
    }
 }
--- a/pageserver/src/tenant/storage_layer/layer.rs
+++ b/pageserver/src/tenant/storage_layer/layer.rs
@@ -14,10 +14,9 @@ use utils::lsn::Lsn;
 use utils::sync::heavier_once_cell;

 use crate::config::PageServerConf;
-use crate::context::{DownloadBehavior, RequestContext};
+use crate::context::RequestContext;
 use crate::repository::Key;
 use crate::span::debug_assert_current_span_has_tenant_and_timeline_id;
-use crate::task_mgr::TaskKind;
 use crate::tenant::timeline::GetVectoredError;
 use crate::tenant::{remote_timeline_client::LayerFileMetadata, Timeline};

@@ -402,8 +401,8 @@ impl Layer {
        &self.0.path
    }

-    pub(crate) fn debug_str(&self) -> &Arc<str> {
-        &self.0.debug_str
+    pub(crate) fn local_path_str(&self) -> &Arc<str> {
+        &self.0.path_str
    }

    pub(crate) fn metadata(&self) -> LayerFileMetadata {
@@ -528,8 +527,8 @@ struct LayerInner {
    /// Full path to the file; unclear if this should exist anymore.
    path: Utf8PathBuf,

-    /// String representation of the layer, used for traversal id.
-    debug_str: Arc<str>,
+    /// String representation of the full path, used for traversal id.
+    path_str: Arc<str>,

    desc: PersistentLayerDesc,

@@ -736,7 +735,7 @@ impl LayerInner {

        LayerInner {
            conf,
-            debug_str: { format!("timelines/{}/{}", timeline.timeline_id, desc.filename()).into() },
+            path_str: path.to_string().into(),
            path,
            desc,
            timeline: Arc::downgrade(timeline),
@@ -940,20 +939,11 @@ impl LayerInner {
            return Err(DownloadError::DownloadRequired);
        }

-        let download_ctx = ctx
-            .map(|ctx| ctx.detached_child(TaskKind::LayerDownload, DownloadBehavior::Download))
-            .unwrap_or(RequestContext::new(
-                TaskKind::LayerDownload,
-                DownloadBehavior::Download,
-            ));
-
        async move {
            tracing::info!(%reason, "downloading on-demand");

            let init_cancelled = scopeguard::guard((), |_| LAYER_IMPL_METRICS.inc_init_cancelled());
-            let res = self
-                .download_init_and_wait(timeline, permit, download_ctx)
-                .await?;
+            let res = self.download_init_and_wait(timeline, permit).await?;
            scopeguard::ScopeGuard::into_inner(init_cancelled);
            Ok(res)
        }
@@ -992,7 +982,6 @@ impl LayerInner {
        self: &Arc<Self>,
        timeline: Arc<Timeline>,
        permit: heavier_once_cell::InitPermit,
-        ctx: RequestContext,
    ) -> Result<Arc<DownloadedLayer>, DownloadError> {
        debug_assert_current_span_has_tenant_and_timeline_id();

@@ -1022,7 +1011,7 @@ impl LayerInner {
                    .await
                    .unwrap();

-                let res = this.download_and_init(timeline, permit, &ctx).await;
+                let res = this.download_and_init(timeline, permit).await;

                if let Err(res) = tx.send(res) {
                    match res {
@@ -1065,7 +1054,6 @@ impl LayerInner {
        self: &Arc<LayerInner>,
        timeline: Arc<Timeline>,
        permit: heavier_once_cell::InitPermit,
-        ctx: &RequestContext,
    ) -> anyhow::Result<Arc<DownloadedLayer>> {
        let client = timeline
            .remote_client
@@ -1073,12 +1061,7 @@ impl LayerInner {
            .expect("checked before download_init_and_wait");

        let result = client
-            .download_layer_file(
-                &self.desc.filename(),
-                &self.metadata(),
-                &timeline.cancel,
-                ctx,
-            )
+            .download_layer_file(&self.desc.filename(), &self.metadata(), &timeline.cancel)
            .await;

        match result {
--- a/pageserver/src/tenant/tasks.rs
+++ b/pageserver/src/tenant/tasks.rs
@@ -2,7 +2,6 @@
 //! such as compaction and GC

 use std::ops::ControlFlow;
-use std::str::FromStr;
 use std::sync::Arc;
 use std::time::{Duration, Instant};

@@ -10,11 +9,9 @@ use crate::context::{DownloadBehavior, RequestContext};
 use crate::metrics::TENANT_TASK_EVENTS;
 use crate::task_mgr;
 use crate::task_mgr::{TaskKind, BACKGROUND_RUNTIME};
-use crate::tenant::config::defaults::DEFAULT_COMPACTION_PERIOD;
 use crate::tenant::throttle::Stats;
 use crate::tenant::timeline::CompactionError;
 use crate::tenant::{Tenant, TenantState};
-use rand::Rng;
 use tokio_util::sync::CancellationToken;
 use tracing::*;
 use utils::{backoff, completion};
@@ -47,7 +44,6 @@ pub(crate) enum BackgroundLoopKind {
    Compaction,
    Gc,
    Eviction,
-    IngestHouseKeeping,
    ConsumptionMetricsCollectMetrics,
    ConsumptionMetricsSyntheticSizeWorker,
    InitialLogicalSizeCalculation,
@@ -136,30 +132,6 @@ pub fn start_background_loops(
            }
        },
    );
-
-    task_mgr::spawn(
-        BACKGROUND_RUNTIME.handle(),
-        TaskKind::IngestHousekeeping,
-        Some(tenant_shard_id),
-        None,
-        &format!("ingest housekeeping for tenant {tenant_shard_id}"),
-        false,
-        {
-            let tenant = Arc::clone(tenant);
-            let background_jobs_can_start = background_jobs_can_start.cloned();
-            async move {
-                let cancel = task_mgr::shutdown_token();
-                tokio::select! {
-                    _ = cancel.cancelled() => { return Ok(()) },
-                    _ = completion::Barrier::maybe_wait(background_jobs_can_start) => {}
-                };
-                ingest_housekeeping_loop(tenant, cancel)
-                    .instrument(info_span!("ingest_housekeeping_loop", tenant_id = %tenant_shard_id.tenant_id, shard_id = %tenant_shard_id.shard_slug()))
-                    .await;
-                Ok(())
-            }
-        },
-    );
 }

 ///
@@ -407,61 +379,6 @@ async fn gc_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
    TENANT_TASK_EVENTS.with_label_values(&["stop"]).inc();
 }

-async fn ingest_housekeeping_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
-    TENANT_TASK_EVENTS.with_label_values(&["start"]).inc();
-    async {
-        loop {
-            tokio::select! {
-                _ = cancel.cancelled() => {
-                    return;
-                },
-                tenant_wait_result = wait_for_active_tenant(&tenant) => match tenant_wait_result {
-                    ControlFlow::Break(()) => return,
-                    ControlFlow::Continue(()) => (),
-                },
-            }
-
-            // We run ingest housekeeping with the same frequency as compaction: it is not worth
-            // having a distinct setting.  But we don't run it in the same task, because compaction
-            // blocks on acquiring the background job semaphore.
-            let period = tenant.get_compaction_period();
-
-            // If compaction period is set to zero (to disable it), then we will use a reasonable default
-            let period = if period == Duration::ZERO {
-                humantime::Duration::from_str(DEFAULT_COMPACTION_PERIOD)
-                    .unwrap()
-                    .into()
-            } else {
-                period
-            };
-
-            // Jitter the period by +/- 5%
-            let period =
-                rand::thread_rng().gen_range((period * (95)) / 100..(period * (105)) / 100);
-
-            // Always sleep first: we do not need to do ingest housekeeping early in the lifetime of
-            // a tenant, since it won't have started writing any ephemeral files yet.
-            if tokio::time::timeout(period, cancel.cancelled())
-                .await
-                .is_ok()
-            {
-                break;
-            }
-
-            let started_at = Instant::now();
-            tenant.ingest_housekeeping().await;
-
-            warn_when_period_overrun(
-                started_at.elapsed(),
-                period,
-                BackgroundLoopKind::IngestHouseKeeping,
-            );
-        }
-    }
-    .await;
-    TENANT_TASK_EVENTS.with_label_values(&["stop"]).inc();
-}
-
 async fn wait_for_active_tenant(tenant: &Arc<Tenant>) -> ControlFlow<()> {
    // if the tenant has a proper status already, no need to wait for anything
    if tenant.current_state() == TenantState::Active {
@@ -503,6 +420,8 @@ pub(crate) async fn random_init_delay(
    period: Duration,
    cancel: &CancellationToken,
 ) -> Result<(), Cancelled> {
+    use rand::Rng;
+
    if period == Duration::ZERO {
        return Ok(());
    }
--- a/pageserver/src/tenant/timeline.rs
+++ b/pageserver/src/tenant/timeline.rs
@@ -16,11 +16,8 @@ use enumset::EnumSet;
 use fail::fail_point;
 use once_cell::sync::Lazy;
 use pageserver_api::{
-    key::{
-        AUX_FILES_KEY, METADATA_KEY_BEGIN_PREFIX, METADATA_KEY_END_PREFIX, NON_INHERITED_RANGE,
-        NON_INHERITED_SPARSE_RANGE,
-    },
-    keyspace::{KeySpaceAccum, SparseKeyPartitioning},
+    key::{AUX_FILES_KEY, NON_INHERITED_RANGE},
+    keyspace::KeySpaceAccum,
    models::{
        CompactionAlgorithm, DownloadRemoteLayersTaskInfo, DownloadRemoteLayersTaskSpawnRequest,
        EvictionPolicy, InMemoryLayerInfo, LayerMapInfo, TimelineState,
@@ -58,6 +55,8 @@ use std::{
    ops::ControlFlow,
 };

+use crate::deletion_queue::DeletionQueueClient;
+use crate::tenant::timeline::logical_size::CurrentLogicalSize;
 use crate::tenant::{
    layer_map::{LayerMap, SearchResult},
    metadata::TimelineMetadata,
@@ -67,7 +66,6 @@ use crate::{
    disk_usage_eviction_task::DiskUsageEvictionInfo,
    pgdatadir_mapping::CollectKeySpaceError,
 };
-use crate::{deletion_queue::DeletionQueueClient, metrics::GetKind};
 use crate::{
    disk_usage_eviction_task::finite_f32,
    tenant::storage_layer::{
@@ -79,9 +77,6 @@ use crate::{
 use crate::{
    disk_usage_eviction_task::EvictionCandidate, tenant::storage_layer::delta_layer::DeltaEntry,
 };
-use crate::{
-    metrics::ScanLatencyOngoingRecording, tenant::timeline::logical_size::CurrentLogicalSize,
-};
 use crate::{pgdatadir_mapping::LsnForTimestamp, tenant::tasks::BackgroundLoopKind};
 use crate::{
    pgdatadir_mapping::{AuxFilesDirectory, DirectoryKind},
@@ -91,7 +86,7 @@ use crate::{
 use crate::config::PageServerConf;
 use crate::keyspace::{KeyPartitioning, KeySpace};
 use crate::metrics::{
-    TimelineMetrics, MATERIALIZED_PAGE_CACHE_HIT, MATERIALIZED_PAGE_CACHE_HIT_DIRECT,
+    GetKind, TimelineMetrics, MATERIALIZED_PAGE_CACHE_HIT, MATERIALIZED_PAGE_CACHE_HIT_DIRECT,
 };
 use crate::pgdatadir_mapping::CalculateLogicalSizeError;
 use crate::tenant::config::TenantConfOpt;
@@ -142,25 +137,6 @@ pub(super) enum FlushLoopState {
    Exited,
 }

-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-pub enum ImageLayerCreationMode {
-    /// Try to create image layers based on `time_for_new_image_layer`. Used in compaction code path.
-    Try,
-    /// Force creating the image layers if possible. For now, no image layers will be created
-    /// for metadata keys. Used in compaction code path with force flag enabled.
-    Force,
-    /// Initial ingestion of the data, and no data should be dropped in this function. This
-    /// means that no metadata keys should be included in the partitions. Used in flush frozen layer
-    /// code path.
-    Initial,
-}
-
-impl std::fmt::Display for ImageLayerCreationMode {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{:?}", self)
-    }
-}
-
 /// Wrapper for key range to provide reverse ordering by range length for BinaryHeap
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub(crate) struct Hole {
@@ -330,7 +306,7 @@ pub struct Timeline {

    // List of child timelines and their branch points. This is needed to avoid
    // garbage collecting data that is still needed by the child timelines.
-    pub(crate) gc_info: std::sync::RwLock<GcInfo>,
+    pub gc_info: std::sync::RwLock<GcInfo>,

    // It may change across major versions so for simplicity
    // keep it after running initdb for a timeline.
@@ -341,7 +317,7 @@ pub struct Timeline {
    pub initdb_lsn: Lsn,

    /// When did we last calculate the partitioning?
-    partitioning: tokio::sync::Mutex<((KeyPartitioning, SparseKeyPartitioning), Lsn)>,
+    partitioning: tokio::sync::Mutex<(KeyPartitioning, Lsn)>,

    /// Configuration: how often should the partitioning be recalculated.
    repartition_threshold: u64,
@@ -414,59 +390,33 @@ pub struct WalReceiverInfo {
    pub last_received_msg_ts: u128,
 }

+///
 /// Information about how much history needs to be retained, needed by
 /// Garbage Collection.
-#[derive(Default)]
-pub(crate) struct GcInfo {
+///
+pub struct GcInfo {
    /// Specific LSNs that are needed.
    ///
    /// Currently, this includes all points where child branches have
    /// been forked off from. In the future, could also include
    /// explicit user-defined snapshot points.
-    pub(crate) retain_lsns: Vec<Lsn>,
+    pub retain_lsns: Vec<Lsn>,

-    /// The cutoff coordinates, which are combined by selecting the minimum.
-    pub(crate) cutoffs: GcCutoffs,
-}
-
-impl GcInfo {
-    pub(crate) fn min_cutoff(&self) -> Lsn {
-        self.cutoffs.select_min()
-    }
-}
-
-/// The `GcInfo` component describing which Lsns need to be retained.
-#[derive(Debug)]
-pub(crate) struct GcCutoffs {
-    /// Keep everything newer than this point.
+    /// In addition to 'retain_lsns', keep everything newer than this
+    /// point.
    ///
    /// This is calculated by subtracting 'gc_horizon' setting from
    /// last-record LSN
    ///
    /// FIXME: is this inclusive or exclusive?
-    pub(crate) horizon: Lsn,
+    pub horizon_cutoff: Lsn,

    /// In addition to 'retain_lsns' and 'horizon_cutoff', keep everything newer than this
    /// point.
    ///
    /// This is calculated by finding a number such that a record is needed for PITR
    /// if only if its LSN is larger than 'pitr_cutoff'.
-    pub(crate) pitr: Lsn,
-}
-
-impl Default for GcCutoffs {
-    fn default() -> Self {
-        Self {
-            horizon: Lsn::INVALID,
-            pitr: Lsn::INVALID,
-        }
-    }
-}
-
-impl GcCutoffs {
-    fn select_min(&self) -> Lsn {
-        std::cmp::min(self.horizon, self.pitr)
-    }
+    pub pitr_cutoff: Lsn,
 }

 /// An error happened in a get() operation.
@@ -495,6 +445,7 @@ pub(crate) enum PageReconstructError {

 #[derive(Debug)]
 pub struct MissingKeyError {
+    stuck_at_lsn: bool,
    key: Key,
    shard: ShardNumber,
    cont_lsn: Lsn,
@@ -506,13 +457,23 @@ pub struct MissingKeyError {

 impl std::fmt::Display for MissingKeyError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "could not find data for key {} (shard {:?}) at LSN {}, request LSN {}",
-            self.key, self.shard, self.cont_lsn, self.request_lsn
-        )?;
-        if let Some(ref ancestor_lsn) = self.ancestor_lsn {
-            write!(f, ", ancestor {}", ancestor_lsn)?;
+        if self.stuck_at_lsn {
+            // Records are found in this timeline but no image layer or initial delta record was found.
+            write!(
+                f,
+                "could not find layer with more data for key {} (shard {:?}) at LSN {}, request LSN {}",
+                self.key, self.shard, self.cont_lsn, self.request_lsn
+            )?;
+            if let Some(ref ancestor_lsn) = self.ancestor_lsn {
+                write!(f, ", ancestor {}", ancestor_lsn)?;
+            }
+        } else {
+            // No records in this timeline.
+            write!(
+                f,
+                "could not find data for key {} (shard {:?}) at LSN {}, for request at LSN {}",
+                self.key, self.shard, self.cont_lsn, self.request_lsn
+            )?;
        }

        if !self.traversal_path.is_empty() {
@@ -588,8 +549,8 @@ pub(crate) enum GetVectoredError {
    #[error("Requested at invalid LSN: {0}")]
    InvalidLsn(Lsn),

-    #[error("Requested key not found: {0}")]
-    MissingKey(MissingKeyError),
+    #[error("Requested key {0} not found")]
+    MissingKey(Key),

    #[error(transparent)]
    GetReadyAncestorError(GetReadyAncestorError),
@@ -698,7 +659,7 @@ impl From<GetVectoredError> for PageReconstructError {
            GetVectoredError::Cancelled => PageReconstructError::Cancelled,
            GetVectoredError::InvalidLsn(_) => PageReconstructError::Other(anyhow!("Invalid LSN")),
            err @ GetVectoredError::Oversized(_) => PageReconstructError::Other(err.into()),
-            GetVectoredError::MissingKey(err) => PageReconstructError::MissingKey(err),
+            err @ GetVectoredError::MissingKey(_) => PageReconstructError::Other(err.into()),
            GetVectoredError::GetReadyAncestorError(err) => PageReconstructError::from(err),
            GetVectoredError::Other(err) => PageReconstructError::Other(err),
        }
@@ -890,15 +851,16 @@ impl Timeline {
                            value
                        }
                    }
-                    None => Err(PageReconstructError::MissingKey(MissingKeyError {
-                        key,
-                        shard: self.shard_identity.get_shard_number(&key),
-                        cont_lsn: Lsn(0),
-                        request_lsn: lsn,
-                        ancestor_lsn: None,
-                        traversal_path: Vec::new(),
-                        backtrace: None,
-                    })),
+                    None => {
+                        error!(
+                            "Expected {}, but singular vectored get returned nothing",
+                            key
+                        );
+                        Err(PageReconstructError::Other(anyhow!(
+                            "Singular vectored get did not return a value for {}",
+                            key
+                        )))
+                    }
                }
            }
        }
@@ -1048,70 +1010,6 @@ impl Timeline {
        res
    }

-    /// Scan the keyspace and return all existing key-values in the keyspace. This currently uses vectored
-    /// get underlying. Normal vectored get would throw an error when a key in the keyspace is not found
-    /// during the search, but for the scan interface, it returns all existing key-value pairs, and does
-    /// not expect each single key in the key space will be found. The semantics is closer to the RocksDB
-    /// scan iterator interface. We could optimize this interface later to avoid some checks in the vectored
-    /// get path to maintain and split the probing and to-be-probe keyspace. We also need to ensure that
-    /// the scan operation will not cause OOM in the future.
-    #[allow(dead_code)]
-    pub(crate) async fn scan(
-        &self,
-        keyspace: KeySpace,
-        lsn: Lsn,
-        ctx: &RequestContext,
-    ) -> Result<BTreeMap<Key, Result<Bytes, PageReconstructError>>, GetVectoredError> {
-        if !lsn.is_valid() {
-            return Err(GetVectoredError::InvalidLsn(lsn));
-        }
-
-        trace!(
-            "key-value scan request for {:?}@{} from task kind {:?}",
-            keyspace,
-            lsn,
-            ctx.task_kind()
-        );
-
-        // We should generalize this into Keyspace::contains in the future.
-        for range in &keyspace.ranges {
-            if range.start.field1 < METADATA_KEY_BEGIN_PREFIX
-                || range.end.field1 >= METADATA_KEY_END_PREFIX
-            {
-                return Err(GetVectoredError::Other(anyhow::anyhow!(
-                    "only metadata keyspace can be scanned"
-                )));
-            }
-        }
-
-        let start = crate::metrics::SCAN_LATENCY
-            .for_task_kind(ctx.task_kind())
-            .map(ScanLatencyOngoingRecording::start_recording);
-
-        // start counting after throttle so that throttle time
-        // is always less than observation time
-        let throttled = self
-            .timeline_get_throttle
-            // assume scan = 1 quota for now until we find a better way to process this
-            .throttle(ctx, 1)
-            .await;
-
-        let vectored_res = self
-            .get_vectored_impl(
-                keyspace.clone(),
-                lsn,
-                ValuesReconstructState::default(),
-                ctx,
-            )
-            .await;
-
-        if let Some(recording) = start {
-            recording.observe(throttled);
-        }
-
-        vectored_res
-    }
-
    /// Not subject to [`Self::timeline_get_throttle`].
    pub(super) async fn get_vectored_sequential_impl(
        &self,
@@ -1120,7 +1018,6 @@ impl Timeline {
        ctx: &RequestContext,
    ) -> Result<BTreeMap<Key, Result<Bytes, PageReconstructError>>, GetVectoredError> {
        let mut values = BTreeMap::new();
-
        for range in keyspace.ranges {
            let mut key = range.start;
            while key != range.end {
@@ -1133,17 +1030,16 @@ impl Timeline {
                    Err(Cancelled | AncestorStopping(_)) => {
                        return Err(GetVectoredError::Cancelled)
                    }
-                    Err(MissingKey(_))
-                        if NON_INHERITED_RANGE.contains(&key)
-                            || NON_INHERITED_SPARSE_RANGE.contains(&key) =>
-                    {
-                        // Ignore missing key error for aux key range. TODO: currently, we assume non_inherited_range == aux_key_range.
-                        // When we add more types of keys into the page server, we should revisit this part of code and throw errors
-                        // accordingly.
-                        key = key.next();
-                    }
-                    Err(MissingKey(err)) => {
-                        return Err(GetVectoredError::MissingKey(err));
+                    // we only capture stuck_at_lsn=false now until we figure out https://github.com/neondatabase/neon/issues/7380
+                    Err(MissingKey(MissingKeyError {
+                        stuck_at_lsn: false,
+                        ..
+                    })) if !NON_INHERITED_RANGE.contains(&key) => {
+                        // The vectored read path handles non inherited keys specially.
+                        // If such a a key cannot be reconstructed from the current timeline,
+                        // the vectored read path returns a key level error as opposed to a top
+                        // level error.
+                        return Err(GetVectoredError::MissingKey(key));
                    }
                    Err(Other(err))
                        if err
@@ -1230,11 +1126,6 @@ impl Timeline {
        lsn: Lsn,
        ctx: &RequestContext,
    ) {
-        if keyspace.overlaps(&Key::metadata_key_range()) {
-            // skip validation for metadata key range
-            return;
-        }
-
        let sequential_res = self
            .get_vectored_sequential_impl(keyspace.clone(), lsn, ctx)
            .await;
@@ -1244,7 +1135,7 @@ impl Timeline {
            match (lhs, rhs) {
                (Oversized(l), Oversized(r)) => l == r,
                (InvalidLsn(l), InvalidLsn(r)) => l == r,
-                (MissingKey(l), MissingKey(r)) => l.key == r.key,
+                (MissingKey(l), MissingKey(r)) => l == r,
                (GetReadyAncestorError(_), GetReadyAncestorError(_)) => true,
                (Other(_), Other(_)) => true,
                _ => false,
@@ -1258,11 +1149,6 @@ impl Timeline {
                panic!(concat!("Sequential get failed with {}, but vectored get did not",
                               " - keyspace={:?} lsn={}"),
                       seq_err, keyspace, lsn) },
-            (Ok(_), Err(GetVectoredError::GetReadyAncestorError(GetReadyAncestorError::AncestorLsnTimeout(_)))) => {
-                // Sequential get runs after vectored get, so it is possible for the later
-                // to time out while waiting for its ancestor's Lsn to become ready and for the
-                // former to succeed (it essentially has a doubled wait time).
-            },
            (Ok(_), Err(vec_err)) => {
                panic!(concat!("Vectored get failed with {}, but sequential get did not",
                               " - keyspace={:?} lsn={}"),
@@ -1343,12 +1229,6 @@ impl Timeline {
        self.last_record_lsn.load()
    }

-    /// Subscribe to callers of wait_lsn(). The value of the channel is None if there are no
-    /// wait_lsn() calls in progress, and Some(Lsn) if there is an active waiter for wait_lsn().
-    pub(crate) fn subscribe_for_wait_lsn_updates(&self) -> watch::Receiver<Option<Lsn>> {
-        self.last_record_lsn.status_receiver()
-    }
-
    pub(crate) fn get_disk_consistent_lsn(&self) -> Lsn {
        self.disk_consistent_lsn.load()
    }
@@ -1498,11 +1378,11 @@ impl Timeline {
        self.flush_frozen_layers_and_wait(to_lsn).await
    }

-    // Check if an open ephemeral layer should be closed: this provides
-    // background enforcement of checkpoint interval if there is no active WAL receiver, to avoid keeping
-    // an ephemeral layer open forever when idle.  It also freezes layers if the global limit on
-    // ephemeral layer bytes has been breached.
-    pub(super) async fn maybe_freeze_ephemeral_layer(&self) {
+    /// If there is no writer, and conditions for rolling the latest layer are met, then freeze it.
+    ///
+    /// This is for use in background housekeeping, to provide guarantees of layers closing eventually
+    /// even if there are no ongoing writes to drive that.
+    async fn maybe_freeze_ephemeral_layer(&self) {
        let Ok(_write_guard) = self.write_lock.try_lock() else {
            // If the write lock is held, there is an active wal receiver: rolling open layers
            // is their responsibility while they hold this lock.
@@ -1529,11 +1409,13 @@ impl Timeline {
                // we are a sharded tenant and have skipped some WAL
                let last_freeze_ts = *self.last_freeze_ts.read().unwrap();
                if last_freeze_ts.elapsed() >= self.get_checkpoint_timeout() {
-                    // Only do this if have been layer-less longer than get_checkpoint_timeout, so that a shard
-                    // without any data ingested (yet) doesn't write a remote index as soon as it
+                    // This should be somewhat rare, so we log it at INFO level.
+                    //
+                    // We checked for checkpoint timeout so that a shard without any
+                    // data ingested (yet) doesn't write a remote index as soon as it
                    // sees its LSN advance: we only do this if we've been layer-less
                    // for some time.
-                    tracing::debug!(
+                    tracing::info!(
                        "Advancing disk_consistent_lsn past WAL ingest gap {} -> {}",
                        disk_consistent_lsn,
                        last_record_lsn
@@ -1623,6 +1505,11 @@ impl Timeline {
            (guard, permit)
        };

+        // Prior to compaction, check if an open ephemeral layer should be closed: this provides
+        // background enforcement of checkpoint interval if there is no active WAL receiver, to avoid keeping
+        // an ephemeral layer open forever when idle.
+        self.maybe_freeze_ephemeral_layer().await;
+
        // this wait probably never needs any "long time spent" logging, because we already nag if
        // compaction task goes over it's period (20s) which is quite often in production.
        let (_guard, _permit) = tokio::select! {
@@ -1984,15 +1871,6 @@ const REPARTITION_FREQ_IN_CHECKPOINT_DISTANCE: u64 = 10;

 // Private functions
 impl Timeline {
-    #[allow(dead_code)]
-    pub(crate) fn get_switch_to_aux_file_v2(&self) -> bool {
-        let tenant_conf = self.tenant_conf.load();
-        tenant_conf
-            .tenant_conf
-            .switch_to_aux_file_v2
-            .unwrap_or(self.conf.default_tenant_conf.switch_to_aux_file_v2)
-    }
-
    pub(crate) fn get_lazy_slru_download(&self) -> bool {
        let tenant_conf = self.tenant_conf.load();
        tenant_conf
@@ -2194,7 +2072,11 @@ impl Timeline {

                write_lock: tokio::sync::Mutex::new(None),

-                gc_info: std::sync::RwLock::new(GcInfo::default()),
+                gc_info: std::sync::RwLock::new(GcInfo {
+                    retain_lsns: Vec::new(),
+                    horizon_cutoff: Lsn(0),
+                    pitr_cutoff: Lsn(0),
+                }),

                latest_gc_cutoff_lsn: Rcu::new(metadata.latest_gc_cutoff_lsn()),
                initdb_lsn: metadata.initdb_lsn(),
@@ -2208,10 +2090,7 @@ impl Timeline {
                    // initial logical size is 0.
                    LogicalSize::empty_initial()
                },
-                partitioning: tokio::sync::Mutex::new((
-                    (KeyPartitioning::new(), KeyPartitioning::new().into_sparse()),
-                    Lsn(0),
-                )),
+                partitioning: tokio::sync::Mutex::new((KeyPartitioning::new(), Lsn(0))),
                repartition_threshold: 0,
                last_image_layer_creation_check_at: AtomicLsn::new(0),

@@ -3027,7 +2906,7 @@ trait TraversalLayerExt {

 impl TraversalLayerExt for Layer {
    fn traversal_id(&self) -> TraversalId {
-        Arc::clone(self.debug_str())
+        Arc::clone(self.local_path_str())
    }
 }

@@ -3103,6 +2982,7 @@ impl Timeline {
                            // Didn't make any progress in last iteration. Error out to avoid
                            // getting stuck in the loop.
                            return Err(PageReconstructError::MissingKey(MissingKeyError {
+                                stuck_at_lsn: true,
                                key,
                                shard: self.shard_identity.get_shard_number(&key),
                                cont_lsn: Lsn(cont_lsn.0 - 1),
@@ -3117,6 +2997,7 @@ impl Timeline {
                }
                ValueReconstructResult::Missing => {
                    return Err(PageReconstructError::MissingKey(MissingKeyError {
+                        stuck_at_lsn: false,
                        key,
                        shard: self.shard_identity.get_shard_number(&key),
                        cont_lsn,
@@ -3211,6 +3092,7 @@ impl Timeline {
            if let Some(SearchResult { lsn_floor, layer }) = layers.search(key, cont_lsn) {
                let layer = guard.get_from_desc(&layer);
                drop(guard);
+
                // Get all the data needed to reconstruct the page version from this layer.
                // But if we have an older cached page image, no need to go past that.
                let lsn_floor = max(cached_lsn + 1, lsn_floor);
@@ -3280,12 +3162,37 @@ impl Timeline {
            // Do not descend into the ancestor timeline for aux files.
            // We don't return a blanket [`GetVectoredError::MissingKey`] to avoid
            // stalling compaction.
-            keyspace.remove_overlapping_with(&KeySpace {
-                ranges: vec![NON_INHERITED_RANGE, NON_INHERITED_SPARSE_RANGE],
-            });
+            // TODO(chi): this will need to be updated for aux files v2 storage
+            if keyspace.overlaps(&NON_INHERITED_RANGE) {
+                let removed = keyspace.remove_overlapping_with(&KeySpace {
+                    ranges: vec![NON_INHERITED_RANGE],
+                });
+
+                for range in removed.ranges {
+                    let mut key = range.start;
+                    while key < range.end {
+                        reconstruct_state.on_key_error(
+                            key,
+                            PageReconstructError::MissingKey(MissingKeyError {
+                                stuck_at_lsn: false,
+                                key,
+                                shard: self.shard_identity.get_shard_number(&key),
+                                cont_lsn,
+                                request_lsn,
+                                ancestor_lsn: None,
+                                traversal_path: Vec::default(),
+                                backtrace: if cfg!(test) {
+                                    Some(std::backtrace::Backtrace::force_capture())
+                                } else {
+                                    None
+                                },
+                            }),
+                        );
+                        key = key.next();
+                    }
+                }
+            }

-            // Keyspace is fully retrieved, no ancestor timeline, or metadata scan (where we do not look
-            // into ancestor timelines). TODO: is there any other metadata which we want to inherit?
            if keyspace.total_raw_size() == 0 || timeline.ancestor_timeline.is_none() {
                break;
            }
@@ -3300,23 +3207,13 @@ impl Timeline {
        }

        if keyspace.total_raw_size() != 0 {
-            return Err(GetVectoredError::MissingKey(MissingKeyError {
-                key: keyspace.start().unwrap(), /* better if we can store the full keyspace */
-                shard: self
-                    .shard_identity
-                    .get_shard_number(&keyspace.start().unwrap()),
-                cont_lsn,
-                request_lsn,
-                ancestor_lsn: Some(timeline.ancestor_lsn),
-                traversal_path: vec![],
-                backtrace: None,
-            }));
+            return Err(GetVectoredError::MissingKey(keyspace.start().unwrap()));
        }

        Ok(())
    }

-    /// Collect the reconstruct data for a keyspace from the specified timeline.
+    /// Collect the reconstruct data for a ketspace from the specified timeline.
    ///
    /// Maintain a fringe [`LayerFringe`] which tracks all the layers that intersect
    /// the current keyspace. The current keyspace of the search at any given timeline
@@ -3745,103 +3642,66 @@ impl Timeline {
        // files instead. This is possible as long as *all* the data imported into the
        // repository have the same LSN.
        let lsn_range = frozen_layer.get_lsn_range();
-
-        // Whether to directly create image layers for this flush, or flush them as delta layers
-        let create_image_layer =
-            lsn_range.start == self.initdb_lsn && lsn_range.end == Lsn(self.initdb_lsn.0 + 1);
-
-        #[cfg(test)]
-        {
-            match &mut *self.flush_loop_state.lock().unwrap() {
-                FlushLoopState::NotStarted | FlushLoopState::Exited => {
-                    panic!("flush loop not running")
-                }
-                FlushLoopState::Running {
-                    expect_initdb_optimization,
-                    initdb_optimization_count,
-                    ..
-                } => {
-                    if create_image_layer {
+        let (layers_to_upload, delta_layer_to_add) =
+            if lsn_range.start == self.initdb_lsn && lsn_range.end == Lsn(self.initdb_lsn.0 + 1) {
+                #[cfg(test)]
+                match &mut *self.flush_loop_state.lock().unwrap() {
+                    FlushLoopState::NotStarted | FlushLoopState::Exited => {
+                        panic!("flush loop not running")
+                    }
+                    FlushLoopState::Running {
+                        initdb_optimization_count,
+                        ..
+                    } => {
                        *initdb_optimization_count += 1;
-                    } else {
+                    }
+                }
+                // Note: The 'ctx' in use here has DownloadBehavior::Error. We should not
+                // require downloading anything during initial import.
+                let (partitioning, _lsn) = self
+                    .repartition(
+                        self.initdb_lsn,
+                        self.get_compaction_target_size(),
+                        EnumSet::empty(),
+                        ctx,
+                    )
+                    .await?;
+
+                if self.cancel.is_cancelled() {
+                    return Err(FlushLayerError::Cancelled);
+                }
+
+                // For image layers, we add them immediately into the layer map.
+                (
+                    self.create_image_layers(&partitioning, self.initdb_lsn, true, ctx)
+                        .await?,
+                    None,
+                )
+            } else {
+                #[cfg(test)]
+                match &mut *self.flush_loop_state.lock().unwrap() {
+                    FlushLoopState::NotStarted | FlushLoopState::Exited => {
+                        panic!("flush loop not running")
+                    }
+                    FlushLoopState::Running {
+                        expect_initdb_optimization,
+                        ..
+                    } => {
                        assert!(!*expect_initdb_optimization, "expected initdb optimization");
                    }
                }
-            }
-        }
-
-        let (layers_to_upload, delta_layer_to_add) = if create_image_layer {
-            // Note: The 'ctx' in use here has DownloadBehavior::Error. We should not
-            // require downloading anything during initial import.
-            let ((rel_partition, metadata_partition), _lsn) = self
-                .repartition(
-                    self.initdb_lsn,
-                    self.get_compaction_target_size(),
-                    EnumSet::empty(),
-                    ctx,
+                // Normal case, write out a L0 delta layer file.
+                // `create_delta_layer` will not modify the layer map.
+                // We will remove frozen layer and add delta layer in one atomic operation later.
+                let layer = self.create_delta_layer(&frozen_layer, ctx).await?;
+                (
+                    // FIXME: even though we have a single image and single delta layer assumption
+                    // we push them to vec
+                    vec![layer.clone()],
+                    Some(layer),
                )
-                .await?;
-
-            if self.cancel.is_cancelled() {
-                return Err(FlushLayerError::Cancelled);
-            }
-
-            // For metadata, always create delta layers.
-            let delta_layer = if !metadata_partition.parts.is_empty() {
-                assert_eq!(
-                    metadata_partition.parts.len(),
-                    1,
-                    "currently sparse keyspace should only contain a single aux file keyspace"
-                );
-                let metadata_keyspace = &metadata_partition.parts[0];
-                assert_eq!(
-                    metadata_keyspace.0.ranges.len(),
-                    1,
-                    "aux file keyspace should be a single range"
-                );
-                self.create_delta_layer(
-                    &frozen_layer,
-                    ctx,
-                    Some(metadata_keyspace.0.ranges[0].clone()),
-                )
-                .await?
-            } else {
-                None
            };

-            // For image layers, we add them immediately into the layer map.
-            let mut layers_to_upload = Vec::new();
-            layers_to_upload.extend(
-                self.create_image_layers(
-                    &rel_partition,
-                    self.initdb_lsn,
-                    ImageLayerCreationMode::Initial,
-                    ctx,
-                )
-                .await?,
-            );
-
-            if let Some(delta_layer) = delta_layer {
-                layers_to_upload.push(delta_layer.clone());
-                (layers_to_upload, Some(delta_layer))
-            } else {
-                (layers_to_upload, None)
-            }
-        } else {
-            // Normal case, write out a L0 delta layer file.
-            // `create_delta_layer` will not modify the layer map.
-            // We will remove frozen layer and add delta layer in one atomic operation later.
-            let Some(layer) = self.create_delta_layer(&frozen_layer, ctx, None).await? else {
-                panic!("delta layer cannot be empty if no filter is applied");
-            };
-            (
-                // FIXME: even though we have a single image and single delta layer assumption
-                // we push them to vec
-                vec![layer.clone()],
-                Some(layer),
-            )
-        };
-
        pausable_failpoint!("flush-layer-cancel-after-writing-layer-out-pausable");

        if self.cancel.is_cancelled() {
@@ -3961,18 +3821,12 @@ impl Timeline {
        self: &Arc<Self>,
        frozen_layer: &Arc<InMemoryLayer>,
        ctx: &RequestContext,
-        key_range: Option<Range<Key>>,
-    ) -> anyhow::Result<Option<ResidentLayer>> {
+    ) -> anyhow::Result<ResidentLayer> {
        let self_clone = Arc::clone(self);
        let frozen_layer = Arc::clone(frozen_layer);
        let ctx = ctx.attached_child();
        let work = async move {
-            let Some(new_delta) = frozen_layer
-                .write_to_disk(&self_clone, &ctx, key_range)
-                .await?
-            else {
-                return Ok(None);
-            };
+            let new_delta = frozen_layer.write_to_disk(&self_clone, &ctx).await?;
            // The write_to_disk() above calls writer.finish() which already did the fsync of the inodes.
            // We just need to fsync the directory in which these inodes are linked,
            // which we know to be the timeline directory.
@@ -3991,7 +3845,7 @@ impl Timeline {
                .sync_all()
                .await
                .fatal_err("VirtualFile::sync_all timeline dir");
-            anyhow::Ok(Some(new_delta))
+            anyhow::Ok(new_delta)
        };
        // Before tokio-epoll-uring, we ran write_to_disk & the sync_all inside spawn_blocking.
        // Preserve that behavior to maintain the same behavior for `virtual_file_io_engine=std-fs`.
@@ -4018,20 +3872,19 @@ impl Timeline {
        partition_size: u64,
        flags: EnumSet<CompactFlags>,
        ctx: &RequestContext,
-    ) -> anyhow::Result<((KeyPartitioning, SparseKeyPartitioning), Lsn)> {
+    ) -> anyhow::Result<(KeyPartitioning, Lsn)> {
        let Ok(mut partitioning_guard) = self.partitioning.try_lock() else {
            // NB: there are two callers, one is the compaction task, of which there is only one per struct Tenant and hence Timeline.
            // The other is the initdb optimization in flush_frozen_layer, used by `boostrap_timeline`, which runs before `.activate()`
            // and hence before the compaction task starts.
            anyhow::bail!("repartition() called concurrently, this should not happen");
        };
-        let ((dense_partition, sparse_partition), partition_lsn) = &*partitioning_guard;
-        if lsn < *partition_lsn {
+        if lsn < partitioning_guard.1 {
            anyhow::bail!("repartition() called with LSN going backwards, this should not happen");
        }

-        let distance = lsn.0 - partition_lsn.0;
-        if *partition_lsn != Lsn(0)
+        let distance = lsn.0 - partitioning_guard.1 .0;
+        if partitioning_guard.1 != Lsn(0)
            && distance <= self.repartition_threshold
            && !flags.contains(CompactFlags::ForceRepartition)
        {
@@ -4040,24 +3893,37 @@ impl Timeline {
                threshold = self.repartition_threshold,
                "no repartitioning needed"
            );
-            return Ok((
-                (dense_partition.clone(), sparse_partition.clone()),
-                *partition_lsn,
-            ));
+            return Ok((partitioning_guard.0.clone(), partitioning_guard.1));
        }

-        let (dense_ks, sparse_ks) = self.collect_keyspace(lsn, ctx).await?;
-        let dense_partitioning = dense_ks.partition(&self.shard_identity, partition_size);
-        let sparse_partitioning = SparseKeyPartitioning {
-            parts: vec![sparse_ks],
-        }; // no partitioning for metadata keys for now
-        *partitioning_guard = ((dense_partitioning, sparse_partitioning), lsn);
+        let keyspace = self.collect_keyspace(lsn, ctx).await?;
+        let partitioning = keyspace.partition(&self.shard_identity, partition_size);
+
+        *partitioning_guard = (partitioning, lsn);

        Ok((partitioning_guard.0.clone(), partitioning_guard.1))
    }

    // Is it time to create a new image layer for the given partition?
    async fn time_for_new_image_layer(&self, partition: &KeySpace, lsn: Lsn) -> bool {
+        let last = self.last_image_layer_creation_check_at.load();
+        if lsn != Lsn(0) {
+            let distance = lsn
+                .checked_sub(last)
+                .expect("Attempt to compact with LSN going backwards");
+
+            let min_distance = self.get_image_layer_creation_check_threshold() as u64
+                * self.get_checkpoint_distance();
+
+            // Skip the expensive delta layer counting below if we've not ingested
+            // sufficient WAL since the last check.
+            if distance.0 < min_distance {
+                return false;
+            }
+        }
+
+        self.last_image_layer_creation_check_at.store(lsn);
+
        let threshold = self.get_image_creation_threshold();

        let guard = self.layers.read().await;
@@ -4107,12 +3973,12 @@ impl Timeline {
        false
    }

-    #[tracing::instrument(skip_all, fields(%lsn, %mode))]
+    #[tracing::instrument(skip_all, fields(%lsn, %force))]
    async fn create_image_layers(
        self: &Arc<Timeline>,
        partitioning: &KeyPartitioning,
        lsn: Lsn,
-        mode: ImageLayerCreationMode,
+        force: bool,
        ctx: &RequestContext,
    ) -> Result<Vec<ResidentLayer>, CreateImageLayersError> {
        let timer = self.metrics.create_images_time_histo.start_timer();
@@ -4129,46 +3995,11 @@ impl Timeline {
        // image layers  <100000000..100000099> and <200000000..200000199> are not completely covering it.
        let mut start = Key::MIN;

-        let check_for_image_layers = {
-            let last_checks_at = self.last_image_layer_creation_check_at.load();
-            let distance = lsn
-                .checked_sub(last_checks_at)
-                .expect("Attempt to compact with LSN going backwards");
-            let min_distance = self.get_image_layer_creation_check_threshold() as u64
-                * self.get_checkpoint_distance();
-
-            // Skip the expensive delta layer counting if this timeline has not ingested sufficient
-            // WAL since the last check.
-            distance.0 >= min_distance
-        };
-
-        if check_for_image_layers {
-            self.last_image_layer_creation_check_at.store(lsn);
-        }
-
        for partition in partitioning.parts.iter() {
            let img_range = start..partition.ranges.last().unwrap().end;
-
-            if partition.overlaps(&Key::metadata_key_range()) {
-                // TODO(chi): The next patch will correctly create image layers for metadata keys, and it would be a
-                // rather big change. Keep this patch small for now.
-                match mode {
-                    ImageLayerCreationMode::Force | ImageLayerCreationMode::Try => {
-                        // skip image layer creation anyways for metadata keys.
-                        start = img_range.end;
-                        continue;
-                    }
-                    ImageLayerCreationMode::Initial => {
-                        return Err(CreateImageLayersError::Other(anyhow::anyhow!("no image layer should be created for metadata keys when flushing frozen layers")));
-                    }
-                }
-            } else if let ImageLayerCreationMode::Try = mode {
-                // check_for_image_layers = false -> skip
-                // check_for_image_layers = true -> check time_for_new_image_layer -> skip/generate
-                if !check_for_image_layers || !self.time_for_new_image_layer(partition, lsn).await {
-                    start = img_range.end;
-                    continue;
-                }
+            if !force && !self.time_for_new_image_layer(partition, lsn).await {
+                start = img_range.end;
+                continue;
            }

            let mut image_layer_writer = ImageLayerWriter::new(
@@ -4248,7 +4079,7 @@ impl Timeline {
                            };

                            // Write all the keys we just read into our new image layer.
-                            image_layer_writer.put_image(img_key, img, ctx).await?;
+                            image_layer_writer.put_image(img_key, img).await?;
                            wrote_keys = true;
                        }
                    }
@@ -4259,7 +4090,7 @@ impl Timeline {
                // Normal path: we have written some data into the new image layer for this
                // partition, so flush it to disk.
                start = img_range.end;
-                let image_layer = image_layer_writer.finish(self, ctx).await?;
+                let image_layer = image_layer_writer.finish(self).await?;
                image_layers.push(image_layer);
            } else {
                // Special case: the image layer may be empty if this is a sharded tenant and the
@@ -4452,7 +4283,7 @@ impl Timeline {
        Ok(())
    }

-    /// Find the Lsns above which layer files need to be retained on
+    /// Update information about which layer files need to be retained on
    /// garbage collection. This is separate from actually performing the GC,
    /// and is updated more frequently, so that compaction can remove obsolete
    /// page versions more aggressively.
@@ -4460,6 +4291,17 @@ impl Timeline {
    /// TODO: that's wishful thinking, compaction doesn't actually do that
    /// currently.
    ///
+    /// The caller specifies how much history is needed with the 3 arguments:
+    ///
+    /// retain_lsns: keep a version of each page at these LSNs
+    /// cutoff_horizon: also keep everything newer than this LSN
+    /// pitr: the time duration required to keep data for PITR
+    ///
+    /// The 'retain_lsns' list is currently used to prevent removing files that
+    /// are needed by child timelines. In the future, the user might be able to
+    /// name additional points in time to retain. The caller is responsible for
+    /// collecting that information.
+    ///
    /// The 'cutoff_horizon' point is used to retain recent versions that might still be
    /// needed by read-only nodes. (As of this writing, the caller just passes
    /// the latest LSN subtracted by a constant, and doesn't do anything smart
@@ -4467,22 +4309,23 @@ impl Timeline {
    ///
    /// The 'pitr' duration is used to calculate a 'pitr_cutoff', which can be used to determine
    /// whether a record is needed for PITR.
+    ///
+    /// NOTE: This function holds a short-lived lock to protect the 'gc_info'
+    /// field, so that the three values passed as argument are stored
+    /// atomically. But the caller is responsible for ensuring that no new
+    /// branches are created that would need to be included in 'retain_lsns',
+    /// for example. The caller should hold `Tenant::gc_cs` lock to ensure
+    /// that.
+    ///
    #[instrument(skip_all, fields(timeline_id=%self.timeline_id))]
-    pub(super) async fn find_gc_cutoffs(
+    pub(super) async fn update_gc_info(
        &self,
+        retain_lsns: Vec<Lsn>,
        cutoff_horizon: Lsn,
        pitr: Duration,
        cancel: &CancellationToken,
        ctx: &RequestContext,
-    ) -> anyhow::Result<GcCutoffs> {
-        let _timer = self
-            .metrics
-            .find_gc_cutoffs_histo
-            .start_timer()
-            .record_on_drop();
-
-        pausable_failpoint!("Timeline::find_gc_cutoffs-pausable");
-
+    ) -> anyhow::Result<()> {
        // First, calculate pitr_cutoff_timestamp and then convert it to LSN.
        //
        // Some unit tests depend on garbage-collection working even when
@@ -4532,10 +4375,14 @@ impl Timeline {
            self.get_last_record_lsn()
        };

-        Ok(GcCutoffs {
-            horizon: cutoff_horizon,
-            pitr: pitr_cutoff,
-        })
+        // Grab the lock and update the values
+        *self.gc_info.write().unwrap() = GcInfo {
+            retain_lsns,
+            horizon_cutoff: cutoff_horizon,
+            pitr_cutoff,
+        };
+
+        Ok(())
    }

    /// Garbage collect layer files on a timeline that are no longer needed.
@@ -4564,8 +4411,8 @@ impl Timeline {
        let (horizon_cutoff, pitr_cutoff, retain_lsns) = {
            let gc_info = self.gc_info.read().unwrap();

-            let horizon_cutoff = min(gc_info.cutoffs.horizon, self.get_disk_consistent_lsn());
-            let pitr_cutoff = gc_info.cutoffs.pitr;
+            let horizon_cutoff = min(gc_info.horizon_cutoff, self.get_disk_consistent_lsn());
+            let pitr_cutoff = gc_info.pitr_cutoff;
            let retain_lsns = gc_info.retain_lsns.clone();
            (horizon_cutoff, pitr_cutoff, retain_lsns)
        };
--- a/pageserver/src/tenant/timeline/compaction.rs
+++ b/pageserver/src/tenant/timeline/compaction.rs
@@ -9,7 +9,7 @@ use std::ops::{Deref, Range};
 use std::sync::Arc;

 use super::layer_manager::LayerManager;
-use super::{CompactFlags, DurationRecorder, ImageLayerCreationMode, RecordedDuration, Timeline};
+use super::{CompactFlags, DurationRecorder, RecordedDuration, Timeline};

 use anyhow::{anyhow, Context};
 use enumset::EnumSet;
@@ -102,7 +102,7 @@ impl Timeline {
            )
            .await
        {
-            Ok(((dense_partitioning, sparse_partitioning), lsn)) => {
+            Ok((partitioning, lsn)) => {
                // Disables access_stats updates, so that the files we read remain candidates for eviction after we're done with them
                let image_ctx = RequestContextBuilder::extend(ctx)
                    .access_stats_behavior(AccessStatsBehavior::Skip)
@@ -115,37 +115,17 @@ impl Timeline {

                // 3. Create new image layers for partitions that have been modified
                // "enough".
-                let dense_layers = self
+                let layers = self
                    .create_image_layers(
-                        &dense_partitioning,
+                        &partitioning,
                        lsn,
-                        if flags.contains(CompactFlags::ForceImageLayerCreation) {
-                            ImageLayerCreationMode::Force
-                        } else {
-                            ImageLayerCreationMode::Try
-                        },
+                        flags.contains(CompactFlags::ForceImageLayerCreation),
                        &image_ctx,
                    )
                    .await
                    .map_err(anyhow::Error::from)?;

-                // For now, nothing will be produced...
-                let sparse_layers = self
-                    .create_image_layers(
-                        &sparse_partitioning.clone().into_dense(),
-                        lsn,
-                        if flags.contains(CompactFlags::ForceImageLayerCreation) {
-                            ImageLayerCreationMode::Force
-                        } else {
-                            ImageLayerCreationMode::Try
-                        },
-                        &image_ctx,
-                    )
-                    .await
-                    .map_err(anyhow::Error::from)?;
-                assert!(sparse_layers.is_empty());
-
-                self.upload_new_image_layers(dense_layers)?;
+                self.upload_new_image_layers(layers)?;
            }
            Err(err) => {
                // no partitioning? This is normal, if the timeline was just created
@@ -520,7 +500,7 @@ impl Timeline {
                            writer
                                .take()
                                .unwrap()
-                                .finish(prev_key.unwrap().next(), self, ctx)
+                                .finish(prev_key.unwrap().next(), self)
                                .await?,
                        );
                        writer = None;
@@ -562,11 +542,7 @@ impl Timeline {
                    );
                }

-                writer
-                    .as_mut()
-                    .unwrap()
-                    .put_value(key, lsn, value, ctx)
-                    .await?;
+                writer.as_mut().unwrap().put_value(key, lsn, value).await?;
            } else {
                debug!(
                    "Dropping key {} during compaction (it belongs on shard {:?})",
@@ -582,7 +558,7 @@ impl Timeline {
            prev_key = Some(key);
        }
        if let Some(writer) = writer {
-            new_layers.push(writer.finish(prev_key.unwrap().next(), self, ctx).await?);
+            new_layers.push(writer.finish(prev_key.unwrap().next(), self).await?);
        }

        // Sync layers
@@ -782,9 +758,8 @@ impl Timeline {
            return Err(CompactionError::ShuttingDown);
        }

-        let (dense_ks, _sparse_ks) = self.collect_keyspace(end_lsn, ctx).await?;
-        // TODO(chi): ignore sparse_keyspace for now, compact it in the future.
-        let mut adaptor = TimelineAdaptor::new(self, (end_lsn, dense_ks));
+        let keyspace = self.collect_keyspace(end_lsn, ctx).await?;
+        let mut adaptor = TimelineAdaptor::new(self, (end_lsn, keyspace));

        pageserver_compaction::compact_tiered::compact_tiered(
            &mut adaptor,
@@ -976,7 +951,7 @@ impl CompactionJobExecutor for TimelineAdaptor {

            let value = val.load(ctx).await?;

-            writer.put_value(key, lsn, value, ctx).await?;
+            writer.put_value(key, lsn, value).await?;

            prev = Some((key, lsn));
        }
@@ -992,7 +967,7 @@ impl CompactionJobExecutor for TimelineAdaptor {
        });

        let new_delta_layer = writer
-            .finish(prev.unwrap().0.next(), &self.timeline, ctx)
+            .finish(prev.unwrap().0.next(), &self.timeline)
            .await?;

        self.new_deltas.push(new_delta_layer);
@@ -1062,11 +1037,11 @@ impl TimelineAdaptor {
                        }
                    }
                };
-                image_layer_writer.put_image(key, img, ctx).await?;
+                image_layer_writer.put_image(key, img).await?;
                key = key.next();
            }
        }
-        let image_layer = image_layer_writer.finish(&self.timeline, ctx).await?;
+        let image_layer = image_layer_writer.finish(&self.timeline).await?;

        self.new_images.push(image_layer);

--- a/pageserver/src/tenant/timeline/walreceiver/connection_manager.rs
+++ b/pageserver/src/tenant/timeline/walreceiver/connection_manager.rs
@@ -22,12 +22,10 @@ use crate::tenant::{debug_assert_current_span_has_tenant_and_timeline_id, Timeli
 use anyhow::Context;
 use chrono::{NaiveDateTime, Utc};
 use pageserver_api::models::TimelineState;
-
+use storage_broker::proto::subscribe_safekeeper_info_request::SubscriptionKey;
+use storage_broker::proto::SafekeeperTimelineInfo;
+use storage_broker::proto::SubscribeSafekeeperInfoRequest;
 use storage_broker::proto::TenantTimelineId as ProtoTenantTimelineId;
-use storage_broker::proto::{
-    FilterTenantTimelineId, MessageType, SafekeeperDiscoveryRequest, SafekeeperDiscoveryResponse,
-    SubscribeByFilterRequest, TypeSubscription, TypedMessage,
-};
 use storage_broker::{BrokerClientChannel, Code, Streaming};
 use tokio_util::sync::CancellationToken;
 use tracing::*;
@@ -91,14 +89,6 @@ pub(super) async fn connection_manager_loop_step(
        .timeline
        .subscribe_for_state_updates();

-    let mut wait_lsn_status = connection_manager_state
-        .timeline
-        .subscribe_for_wait_lsn_updates();
-
-    // TODO: create a separate config option for discovery request interval
-    let discovery_request_interval = connection_manager_state.conf.lagging_wal_timeout;
-    let mut last_discovery_ts: Option<std::time::Instant> = None;
-
    // Subscribe to the broker updates. Stream shares underlying TCP connection
    // with other streams on this client (other connection managers). When
    // object goes out of scope, stream finishes in drop() automatically.
@@ -107,12 +97,10 @@ pub(super) async fn connection_manager_loop_step(

    loop {
        let time_until_next_retry = connection_manager_state.time_until_next_retry();
-        let any_activity = connection_manager_state.wal_connection.is_some()
-            || !connection_manager_state.wal_stream_candidates.is_empty();

        // These things are happening concurrently:
        //
-        //  - cancellation request
+        // - cancellation request
        //  - keep receiving WAL on the current connection
        //      - if the shared state says we need to change connection, disconnect and return
        //      - this runs in a separate task and we receive updates via a watch channel
@@ -120,7 +108,6 @@ pub(super) async fn connection_manager_loop_step(
        //  - receive updates from broker
        //      - this might change the current desired connection
        //  - timeline state changes to something that does not allow walreceiver to run concurrently
-        //  - if there's no connection and no candidates, try to send a discovery request

        // NB: make sure each of the select expressions are cancellation-safe
        // (no need for arms to be cancellation-safe).
@@ -227,65 +214,6 @@ pub(super) async fn connection_manager_loop_step(
                    }
                }
            } => debug!("Waking up for the next retry after waiting for {time_until_next_retry:?}"),
-
-            Some(()) = async {
-                // Reminder: this match arm needs to be cancellation-safe.
-                // Calculating time needed to wait until sending the next discovery request.
-                // Current implementation is conservative and sends discovery requests only when there are no candidates.
-
-                if any_activity {
-                    // No need to send discovery requests if there is an active connection or candidates.
-                    return None;
-                }
-
-                // Waiting for an active wait_lsn request.
-                while wait_lsn_status.borrow().is_none() {
-                    if wait_lsn_status.changed().await.is_err() {
-                        // wait_lsn_status channel was closed, exiting
-                        warn!("wait_lsn_status channel was closed in connection_manager_loop_step");
-                        return None;
-                    }
-                }
-
-                // All preconditions met, preparing to send a discovery request.
-                let now = std::time::Instant::now();
-                let next_discovery_ts = last_discovery_ts
-                    .map(|ts| ts + discovery_request_interval)
-                    .unwrap_or_else(|| now);
-
-                if next_discovery_ts > now {
-                    // Prevent sending discovery requests too frequently.
-                    tokio::time::sleep(next_discovery_ts - now).await;
-                }
-
-                let tenant_timeline_id = Some(ProtoTenantTimelineId {
-                    tenant_id: id.tenant_id.as_ref().to_owned(),
-                    timeline_id: id.timeline_id.as_ref().to_owned(),
-                });
-                let request = SafekeeperDiscoveryRequest { tenant_timeline_id };
-                let msg = TypedMessage {
-                    r#type: MessageType::SafekeeperDiscoveryRequest as i32,
-                    safekeeper_timeline_info: None,
-                    safekeeper_discovery_request: Some(request),
-                    safekeeper_discovery_response: None,
-                    };
-
-                last_discovery_ts = Some(std::time::Instant::now());
-                debug!("No active connection and no candidates, sending discovery request to the broker");
-
-                // Cancellation safety: we want to send a message to the broker, but publish_one()
-                // function can get cancelled by the other select! arm. This is absolutely fine, because
-                // we just want to receive broker updates and discovery is not important if we already
-                // receive updates.
-                //
-                // It is possible that `last_discovery_ts` will be updated, but the message will not be sent.
-                // This is totally fine because of the reason above.
-
-                // This is a fire-and-forget request, we don't care about the response
-                let _ = broker_client.publish_one(msg).await;
-                debug!("Discovery request sent to the broker");
-                None
-            } => {}
        }

        if let Some(new_candidate) = connection_manager_state.next_connection_candidate() {
@@ -303,7 +231,7 @@ async fn subscribe_for_timeline_updates(
    broker_client: &mut BrokerClientChannel,
    id: TenantTimelineId,
    cancel: &CancellationToken,
-) -> Result<Streaming<TypedMessage>, Cancelled> {
+) -> Result<Streaming<SafekeeperTimelineInfo>, Cancelled> {
    let mut attempt = 0;
    loop {
        exponential_backoff(
@@ -316,27 +244,17 @@ async fn subscribe_for_timeline_updates(
        attempt += 1;

        // subscribe to the specific timeline
-        let request = SubscribeByFilterRequest {
-            types: vec![
-                TypeSubscription {
-                    r#type: MessageType::SafekeeperTimelineInfo as i32,
-                },
-                TypeSubscription {
-                    r#type: MessageType::SafekeeperDiscoveryResponse as i32,
-                },
-            ],
-            tenant_timeline_id: Some(FilterTenantTimelineId {
-                enabled: true,
-                tenant_timeline_id: Some(ProtoTenantTimelineId {
-                    tenant_id: id.tenant_id.as_ref().to_owned(),
-                    timeline_id: id.timeline_id.as_ref().to_owned(),
-                }),
-            }),
+        let key = SubscriptionKey::TenantTimelineId(ProtoTenantTimelineId {
+            tenant_id: id.tenant_id.as_ref().to_owned(),
+            timeline_id: id.timeline_id.as_ref().to_owned(),
+        });
+        let request = SubscribeSafekeeperInfoRequest {
+            subscription_key: Some(key),
        };

        match {
            tokio::select! {
-                r = broker_client.subscribe_by_filter(request) => { r }
+                r = broker_client.subscribe_safekeeper_info(request) => { r }
                _ = cancel.cancelled() => { return Err(Cancelled); }
            }
        } {
@@ -480,7 +398,7 @@ struct RetryInfo {
 /// Data about the timeline to connect to, received from the broker.
 #[derive(Debug, Clone)]
 struct BrokerSkTimeline {
-    timeline: SafekeeperDiscoveryResponse,
+    timeline: SafekeeperTimelineInfo,
    /// Time at which the data was fetched from the broker last time, to track the stale data.
    latest_update: NaiveDateTime,
 }
@@ -688,41 +606,7 @@ impl ConnectionManagerState {
    }

    /// Adds another broker timeline into the state, if its more recent than the one already added there for the same key.
-    fn register_timeline_update(&mut self, typed_msg: TypedMessage) {
-        let mut is_discovery = false;
-        let timeline_update = match typed_msg.r#type() {
-            MessageType::SafekeeperTimelineInfo => {
-                let info = match typed_msg.safekeeper_timeline_info {
-                    Some(info) => info,
-                    None => {
-                        warn!("bad proto message from broker: no safekeeper_timeline_info");
-                        return;
-                    }
-                };
-                SafekeeperDiscoveryResponse {
-                    safekeeper_id: info.safekeeper_id,
-                    tenant_timeline_id: info.tenant_timeline_id,
-                    commit_lsn: info.commit_lsn,
-                    safekeeper_connstr: info.safekeeper_connstr,
-                    availability_zone: info.availability_zone,
-                }
-            }
-            MessageType::SafekeeperDiscoveryResponse => {
-                is_discovery = true;
-                match typed_msg.safekeeper_discovery_response {
-                    Some(response) => response,
-                    None => {
-                        warn!("bad proto message from broker: no safekeeper_discovery_response");
-                        return;
-                    }
-                }
-            }
-            _ => {
-                // unexpected message
-                return;
-            }
-        };
-
+    fn register_timeline_update(&mut self, timeline_update: SafekeeperTimelineInfo) {
        WALRECEIVER_BROKER_UPDATES.inc();

        let new_safekeeper_id = NodeId(timeline_update.safekeeper_id);
@@ -735,11 +619,7 @@ impl ConnectionManagerState {
        );

        if old_entry.is_none() {
-            info!(
-                ?is_discovery,
-                %new_safekeeper_id,
-                "New SK node was added",
-            );
+            info!("New SK node was added: {new_safekeeper_id}");
            WALRECEIVER_CANDIDATES_ADDED.inc();
        }
    }
@@ -938,7 +818,7 @@ impl ConnectionManagerState {
    fn select_connection_candidate(
        &self,
        node_to_omit: Option<NodeId>,
-    ) -> Option<(NodeId, &SafekeeperDiscoveryResponse, PgConnectionConfig)> {
+    ) -> Option<(NodeId, &SafekeeperTimelineInfo, PgConnectionConfig)> {
        self.applicable_connection_candidates()
            .filter(|&(sk_id, _, _)| Some(sk_id) != node_to_omit)
            .max_by_key(|(_, info, _)| info.commit_lsn)
@@ -948,7 +828,7 @@ impl ConnectionManagerState {
    /// Some safekeepers are filtered by the retry cooldown.
    fn applicable_connection_candidates(
        &self,
-    ) -> impl Iterator<Item = (NodeId, &SafekeeperDiscoveryResponse, PgConnectionConfig)> {
+    ) -> impl Iterator<Item = (NodeId, &SafekeeperTimelineInfo, PgConnectionConfig)> {
        let now = Utc::now().naive_utc();

        self.wal_stream_candidates
@@ -1088,11 +968,19 @@ mod tests {
        latest_update: NaiveDateTime,
    ) -> BrokerSkTimeline {
        BrokerSkTimeline {
-            timeline: SafekeeperDiscoveryResponse {
+            timeline: SafekeeperTimelineInfo {
                safekeeper_id: 0,
                tenant_timeline_id: None,
+                term: 0,
+                last_log_term: 0,
+                flush_lsn: 0,
                commit_lsn,
+                backup_lsn: 0,
+                remote_consistent_lsn: 0,
+                peer_horizon_lsn: 0,
+                local_start_lsn: 0,
                safekeeper_connstr: safekeeper_connstr.to_owned(),
+                http_connstr: safekeeper_connstr.to_owned(),
                availability_zone: None,
            },
            latest_update,
@@ -1535,7 +1423,7 @@ mod tests {

        let harness = TenantHarness::create("switch_to_same_availability_zone")?;
        let mut state = dummy_state(&harness).await;
-        state.conf.availability_zone.clone_from(&test_az);
+        state.conf.availability_zone = test_az.clone();
        let current_lsn = Lsn(100_000).align();
        let now = Utc::now().naive_utc();

@@ -1568,7 +1456,7 @@ mod tests {
        // We have another safekeeper with the same commit_lsn, and it have the same availability zone as
        // the current pageserver.
        let mut same_az_sk = dummy_broker_sk_timeline(current_lsn.0, "same_az", now);
-        same_az_sk.timeline.availability_zone.clone_from(&test_az);
+        same_az_sk.timeline.availability_zone = test_az.clone();

        state.wal_stream_candidates = HashMap::from([
            (
--- a/pageserver/src/virtual_file.rs
+++ b/pageserver/src/virtual_file.rs
@@ -10,7 +10,6 @@
 //! This is similar to PostgreSQL's virtual file descriptor facility in
 //! src/backend/storage/file/fd.c
 //!
-use crate::context::RequestContext;
 use crate::metrics::{StorageIoOperation, STORAGE_IO_SIZE, STORAGE_IO_TIME_METRIC};

 use crate::page_cache::PageWriteGuard;
@@ -33,11 +32,11 @@ pub use io_engine::feature_test as io_engine_feature_test;
 pub use io_engine::FeatureTestResult as IoEngineFeatureTestResult;
 mod metadata;
 mod open_options;
-use self::owned_buffers_io::write::OwnedAsyncWriter;
 pub(crate) use io_engine::IoEngineKind;
 pub(crate) use metadata::Metadata;
 pub(crate) use open_options::*;

+#[cfg_attr(not(target_os = "linux"), allow(dead_code))]
 pub(crate) mod owned_buffers_io {
    //! Abstractions for IO with owned buffers.
    //!
@@ -616,7 +615,6 @@ impl VirtualFile {
        &self,
        buf: B,
        mut offset: u64,
-        ctx: &RequestContext,
    ) -> (B::Buf, Result<(), Error>) {
        let buf_len = buf.bytes_init();
        if buf_len == 0 {
@@ -625,7 +623,7 @@ impl VirtualFile {
        let mut buf = buf.slice(0..buf_len);
        while !buf.is_empty() {
            let res;
-            (buf, res) = self.write_at(buf, offset, ctx).await;
+            (buf, res) = self.write_at(buf, offset).await;
            match res {
                Ok(0) => {
                    return (
@@ -654,7 +652,6 @@ impl VirtualFile {
    pub async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        buf: B,
-        ctx: &RequestContext,
    ) -> (B::Buf, Result<usize, Error>) {
        let nbytes = buf.bytes_init();
        if nbytes == 0 {
@@ -663,7 +660,7 @@ impl VirtualFile {
        let mut buf = buf.slice(0..nbytes);
        while !buf.is_empty() {
            let res;
-            (buf, res) = self.write(buf, ctx).await;
+            (buf, res) = self.write(buf).await;
            match res {
                Ok(0) => {
                    return (
@@ -687,10 +684,9 @@ impl VirtualFile {
    async fn write<B: IoBuf + Send>(
        &mut self,
        buf: Slice<B>,
-        ctx: &RequestContext,
    ) -> (Slice<B>, Result<usize, std::io::Error>) {
        let pos = self.pos;
-        let (buf, res) = self.write_at(buf, pos, ctx).await;
+        let (buf, res) = self.write_at(buf, pos).await;
        let n = match res {
            Ok(n) => n,
            Err(e) => return (buf, Err(e)),
@@ -728,7 +724,6 @@ impl VirtualFile {
        &self,
        buf: Slice<B>,
        offset: u64,
-        _ctx: &RequestContext, /* TODO: use for metrics: https://github.com/neondatabase/neon/issues/6107 */
    ) -> (Slice<B>, Result<usize, Error>) {
        let file_guard = match self.lock_file().await {
            Ok(file_guard) => file_guard,
@@ -1088,18 +1083,6 @@ impl Drop for VirtualFile {
    }
 }

-impl OwnedAsyncWriter for VirtualFile {
-    #[inline(always)]
-    async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
-        &mut self,
-        buf: B,
-        ctx: &RequestContext,
-    ) -> std::io::Result<(usize, B::Buf)> {
-        let (buf, res) = VirtualFile::write_all(self, buf, ctx).await;
-        res.map(move |v| (v, buf))
-    }
-}
-
 impl OpenFiles {
    fn new(num_slots: usize) -> OpenFiles {
        let mut slots = Box::new(Vec::with_capacity(num_slots));
@@ -1152,9 +1135,6 @@ fn get_open_files() -> &'static OpenFiles {

 #[cfg(test)]
 mod tests {
-    use crate::context::DownloadBehavior;
-    use crate::task_mgr::TaskKind;
-
    use super::*;
    use rand::seq::SliceRandom;
    use rand::thread_rng;
@@ -1186,11 +1166,10 @@ mod tests {
            &self,
            buf: B,
            offset: u64,
-            ctx: &RequestContext,
        ) -> Result<(), Error> {
            match self {
                MaybeVirtualFile::VirtualFile(file) => {
-                    let (_buf, res) = file.write_all_at(buf, offset, ctx).await;
+                    let (_buf, res) = file.write_all_at(buf, offset).await;
                    res
                }
                MaybeVirtualFile::File(file) => {
@@ -1211,11 +1190,10 @@ mod tests {
        async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
            &mut self,
            buf: B,
-            ctx: &RequestContext,
        ) -> Result<(), Error> {
            match self {
                MaybeVirtualFile::VirtualFile(file) => {
-                    let (_buf, res) = file.write_all(buf, ctx).await;
+                    let (_buf, res) = file.write_all(buf).await;
                    res.map(|_| ())
                }
                MaybeVirtualFile::File(file) => {
@@ -1286,7 +1264,6 @@ mod tests {
        OF: Fn(Utf8PathBuf, OpenOptions) -> FT,
        FT: Future<Output = Result<MaybeVirtualFile, std::io::Error>>,
    {
-        let ctx = RequestContext::new(TaskKind::UnitTest, DownloadBehavior::Error);
        let testdir = crate::config::PageServerConf::test_repo_dir(testname);
        std::fs::create_dir_all(&testdir)?;

@@ -1300,7 +1277,7 @@ mod tests {
                .to_owned(),
        )
        .await?;
-        file_a.write_all(b"foobar".to_vec(), &ctx).await?;
+        file_a.write_all(b"foobar".to_vec()).await?;

        // cannot read from a file opened in write-only mode
        let _ = file_a.read_string().await.unwrap_err();
@@ -1309,7 +1286,7 @@ mod tests {
        let mut file_a = openfunc(path_a, OpenOptions::new().read(true).to_owned()).await?;

        // cannot write to a file opened in read-only mode
-        let _ = file_a.write_all(b"bar".to_vec(), &ctx).await.unwrap_err();
+        let _ = file_a.write_all(b"bar".to_vec()).await.unwrap_err();

        // Try simple read
        assert_eq!("foobar", file_a.read_string().await?);
@@ -1351,8 +1328,8 @@ mod tests {
                .to_owned(),
        )
        .await?;
-        file_b.write_all_at(b"BAR".to_vec(), 3, &ctx).await?;
-        file_b.write_all_at(b"FOO".to_vec(), 0, &ctx).await?;
+        file_b.write_all_at(b"BAR".to_vec(), 3).await?;
+        file_b.write_all_at(b"FOO".to_vec(), 0).await?;

        assert_eq!(file_b.read_string_at(2, 3).await?, "OBA");

--- a/pageserver/src/virtual_file/owned_buffers_io/util/size_tracking_writer.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/util/size_tracking_writer.rs
@@ -1,46 +1,33 @@
-use crate::{context::RequestContext, virtual_file::owned_buffers_io::write::OwnedAsyncWriter};
+use crate::virtual_file::{owned_buffers_io::write::OwnedAsyncWriter, VirtualFile};
 use tokio_epoll_uring::{BoundedBuf, IoBuf};

-pub struct Writer<W> {
-    dst: W,
+pub struct Writer {
+    dst: VirtualFile,
    bytes_amount: u64,
 }

-impl<W> Writer<W> {
-    pub fn new(dst: W) -> Self {
+impl Writer {
+    pub fn new(dst: VirtualFile) -> Self {
        Self {
            dst,
            bytes_amount: 0,
        }
    }
-
-    pub fn bytes_written(&self) -> u64 {
-        self.bytes_amount
-    }
-
-    pub fn as_inner(&self) -> &W {
-        &self.dst
-    }
-
    /// Returns the wrapped `VirtualFile` object as well as the number
    /// of bytes that were written to it through this object.
-    #[cfg_attr(target_os = "macos", allow(dead_code))]
-    pub fn into_inner(self) -> (u64, W) {
+    pub fn into_inner(self) -> (u64, VirtualFile) {
        (self.bytes_amount, self.dst)
    }
 }

-impl<W> OwnedAsyncWriter for Writer<W>
-where
-    W: OwnedAsyncWriter,
-{
+impl OwnedAsyncWriter for Writer {
    #[inline(always)]
    async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        buf: B,
-        ctx: &RequestContext,
    ) -> std::io::Result<(usize, B::Buf)> {
-        let (nwritten, buf) = self.dst.write_all(buf, ctx).await?;
+        let (buf, res) = self.dst.write_all(buf).await;
+        let nwritten = res?;
        self.bytes_amount += u64::try_from(nwritten).unwrap();
        Ok((nwritten, buf))
    }
--- a/pageserver/src/virtual_file/owned_buffers_io/write.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/write.rs
@@ -1,26 +1,23 @@
 use bytes::BytesMut;
 use tokio_epoll_uring::{BoundedBuf, IoBuf, Slice};

-use crate::context::RequestContext;
-
 /// A trait for doing owned-buffer write IO.
 /// Think [`tokio::io::AsyncWrite`] but with owned buffers.
 pub trait OwnedAsyncWriter {
    async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        buf: B,
-        ctx: &RequestContext,
    ) -> std::io::Result<(usize, B::Buf)>;
 }

-/// A wrapper aorund an [`OwnedAsyncWriter`] that uses a [`Buffer`] to batch
-/// small writes into larger writes of size [`Buffer::cap`].
+/// A wrapper aorund an [`OwnedAsyncWriter`] that batches smaller writers
+/// into `BUFFER_SIZE`-sized writes.
 ///
 /// # Passthrough Of Large Writers
 ///
-/// Calls to [`BufferedWriter::write_buffered`] that are larger than [`Buffer::cap`]
-/// cause the internal buffer to be flushed prematurely so that the large
-/// buffered write is passed through to the underlying [`OwnedAsyncWriter`].
+/// Buffered writes larger than the `BUFFER_SIZE` cause the internal
+/// buffer to be flushed, even if it is not full yet. Then, the large
+/// buffered write is passed through to the unerlying [`OwnedAsyncWriter`].
 ///
 /// This pass-through is generally beneficial for throughput, but if
 /// the storage backend of the [`OwnedAsyncWriter`] is a shared resource,
@@ -28,186 +25,86 @@ pub trait OwnedAsyncWriter {
 ///
 /// In such cases, a different implementation that always buffers in memory
 /// may be preferable.
-pub struct BufferedWriter<B, W> {
+pub struct BufferedWriter<const BUFFER_SIZE: usize, W> {
    writer: W,
-    /// invariant: always remains Some(buf) except
-    /// - while IO is ongoing => goes back to Some() once the IO completed successfully
-    /// - after an IO error => stays `None` forever
-    /// In these exceptional cases, it's `None`.
-    buf: Option<B>,
+    // invariant: always remains Some(buf)
+    // with buf.capacity() == BUFFER_SIZE except
+    // - while IO is ongoing => goes back to Some() once the IO completed successfully
+    // - after an IO error => stays `None` forever
+    // In these exceptional cases, it's `None`.
+    buf: Option<BytesMut>,
 }

-impl<B, Buf, W> BufferedWriter<B, W>
+impl<const BUFFER_SIZE: usize, W> BufferedWriter<BUFFER_SIZE, W>
 where
-    B: Buffer<IoBuf = Buf> + Send,
-    Buf: IoBuf + Send,
    W: OwnedAsyncWriter,
 {
-    pub fn new(writer: W, buf: B) -> Self {
+    pub fn new(writer: W) -> Self {
        Self {
            writer,
-            buf: Some(buf),
+            buf: Some(BytesMut::with_capacity(BUFFER_SIZE)),
        }
    }

-    pub fn as_inner(&self) -> &W {
-        &self.writer
-    }
-
-    /// Panics if used after any of the write paths returned an error
-    pub fn inspect_buffer(&self) -> &B {
-        self.buf()
-    }
-
-    #[cfg_attr(target_os = "macos", allow(dead_code))]
-    pub async fn flush_and_into_inner(mut self, ctx: &RequestContext) -> std::io::Result<W> {
-        self.flush(ctx).await?;
-
+    pub async fn flush_and_into_inner(mut self) -> std::io::Result<W> {
+        self.flush().await?;
        let Self { buf, writer } = self;
        assert!(buf.is_some());
        Ok(writer)
    }

-    #[inline(always)]
-    fn buf(&self) -> &B {
-        self.buf
-            .as_ref()
-            .expect("must not use after we returned an error")
-    }
-
-    #[cfg_attr(target_os = "macos", allow(dead_code))]
-    pub async fn write_buffered<S: IoBuf + Send>(
-        &mut self,
-        chunk: Slice<S>,
-        ctx: &RequestContext,
-    ) -> std::io::Result<(usize, S)> {
-        let chunk_len = chunk.len();
+    pub async fn write_buffered<B: IoBuf>(&mut self, chunk: Slice<B>) -> std::io::Result<()>
+    where
+        B: IoBuf + Send,
+    {
        // avoid memcpy for the middle of the chunk
-        if chunk.len() >= self.buf().cap() {
-            self.flush(ctx).await?;
+        if chunk.len() >= BUFFER_SIZE {
+            self.flush().await?;
            // do a big write, bypassing `buf`
            assert_eq!(
                self.buf
                    .as_ref()
                    .expect("must not use after an error")
-                    .pending(),
+                    .len(),
                0
            );
-            let (nwritten, chunk) = self.writer.write_all(chunk, ctx).await?;
+            let chunk_len = chunk.len();
+            let (nwritten, chunk) = self.writer.write_all(chunk).await?;
            assert_eq!(nwritten, chunk_len);
-            return Ok((nwritten, chunk));
+            drop(chunk);
+            return Ok(());
        }
        // in-memory copy the < BUFFER_SIZED tail of the chunk
-        assert!(chunk.len() < self.buf().cap());
-        let mut slice = &chunk[..];
-        while !slice.is_empty() {
-            let buf = self.buf.as_mut().expect("must not use after an error");
-            let need = buf.cap() - buf.pending();
-            let have = slice.len();
-            let n = std::cmp::min(need, have);
-            buf.extend_from_slice(&slice[..n]);
-            slice = &slice[n..];
-            if buf.pending() >= buf.cap() {
-                assert_eq!(buf.pending(), buf.cap());
-                self.flush(ctx).await?;
-            }
-        }
-        assert!(slice.is_empty(), "by now we should have drained the chunk");
-        Ok((chunk_len, chunk.into_inner()))
-    }
-
-    /// Strictly less performant variant of [`Self::write_buffered`] that allows writing borrowed data.
-    ///
-    /// It is less performant because we always have to copy the borrowed data into the internal buffer
-    /// before we can do the IO. The [`Self::write_buffered`] can avoid this, which is more performant
-    /// for large writes.
-    pub async fn write_buffered_borrowed(
-        &mut self,
-        mut chunk: &[u8],
-        ctx: &RequestContext,
-    ) -> std::io::Result<usize> {
-        let chunk_len = chunk.len();
+        assert!(chunk.len() < BUFFER_SIZE);
+        let mut chunk = &chunk[..];
        while !chunk.is_empty() {
            let buf = self.buf.as_mut().expect("must not use after an error");
-            let need = buf.cap() - buf.pending();
+            let need = BUFFER_SIZE - buf.len();
            let have = chunk.len();
            let n = std::cmp::min(need, have);
            buf.extend_from_slice(&chunk[..n]);
            chunk = &chunk[n..];
-            if buf.pending() >= buf.cap() {
-                assert_eq!(buf.pending(), buf.cap());
-                self.flush(ctx).await?;
+            if buf.len() >= BUFFER_SIZE {
+                assert_eq!(buf.len(), BUFFER_SIZE);
+                self.flush().await?;
            }
        }
-        Ok(chunk_len)
-    }
-
-    async fn flush(&mut self, ctx: &RequestContext) -> std::io::Result<()> {
-        let buf = self.buf.take().expect("must not use after an error");
-        let buf_len = buf.pending();
-        if buf_len == 0 {
-            self.buf = Some(buf);
-            return Ok(());
-        }
-        let (nwritten, io_buf) = self.writer.write_all(buf.flush(), ctx).await?;
-        assert_eq!(nwritten, buf_len);
-        self.buf = Some(Buffer::reuse_after_flush(io_buf));
+        assert!(chunk.is_empty(), "by now we should have drained the chunk");
        Ok(())
    }
-}

-/// A [`Buffer`] is used by [`BufferedWriter`] to batch smaller writes into larger ones.
-pub trait Buffer {
-    type IoBuf: IoBuf;
-
-    /// Capacity of the buffer. Must not change over the lifetime `self`.`
-    fn cap(&self) -> usize;
-
-    /// Add data to the buffer.
-    /// Panics if there is not enough room to accomodate `other`'s content, i.e.,
-    /// panics if `other.len() > self.cap() - self.pending()`.
-    fn extend_from_slice(&mut self, other: &[u8]);
-
-    /// Number of bytes in the buffer.
-    fn pending(&self) -> usize;
-
-    /// Turns `self` into a [`tokio_epoll_uring::Slice`] of the pending data
-    /// so we can use [`tokio_epoll_uring`] to write it to disk.
-    fn flush(self) -> Slice<Self::IoBuf>;
-
-    /// After the write to disk is done and we have gotten back the slice,
-    /// [`BufferedWriter`] uses this method to re-use the io buffer.
-    fn reuse_after_flush(iobuf: Self::IoBuf) -> Self;
-}
-
-impl Buffer for BytesMut {
-    type IoBuf = BytesMut;
-
-    #[inline(always)]
-    fn cap(&self) -> usize {
-        self.capacity()
-    }
-
-    fn extend_from_slice(&mut self, other: &[u8]) {
-        BytesMut::extend_from_slice(self, other)
-    }
-
-    #[inline(always)]
-    fn pending(&self) -> usize {
-        self.len()
-    }
-
-    fn flush(self) -> Slice<BytesMut> {
-        if self.is_empty() {
-            return self.slice_full();
+    async fn flush(&mut self) -> std::io::Result<()> {
+        let buf = self.buf.take().expect("must not use after an error");
+        if buf.is_empty() {
+            self.buf = Some(buf);
+            return std::io::Result::Ok(());
        }
-        let len = self.len();
-        self.slice(0..len)
-    }
-
-    fn reuse_after_flush(mut iobuf: BytesMut) -> Self {
-        iobuf.clear();
-        iobuf
+        let buf_len = buf.len();
+        let (nwritten, mut buf) = self.writer.write_all(buf).await?;
+        assert_eq!(nwritten, buf_len);
+        buf.clear();
+        self.buf = Some(buf);
+        Ok(())
    }
 }

@@ -215,7 +112,6 @@ impl OwnedAsyncWriter for Vec<u8> {
    async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
        &mut self,
        buf: B,
-        _: &RequestContext,
    ) -> std::io::Result<(usize, B::Buf)> {
        let nbytes = buf.bytes_init();
        if nbytes == 0 {
@@ -229,11 +125,7 @@ impl OwnedAsyncWriter for Vec<u8> {

 #[cfg(test)]
 mod tests {
-    use bytes::BytesMut;
-
    use super::*;
-    use crate::context::{DownloadBehavior, RequestContext};
-    use crate::task_mgr::TaskKind;

    #[derive(Default)]
    struct RecorderWriter {
@@ -243,7 +135,6 @@ mod tests {
        async fn write_all<B: BoundedBuf<Buf = Buf>, Buf: IoBuf + Send>(
            &mut self,
            buf: B,
-            _: &RequestContext,
        ) -> std::io::Result<(usize, B::Buf)> {
            let nbytes = buf.bytes_init();
            if nbytes == 0 {
@@ -256,14 +147,10 @@ mod tests {
        }
    }

-    fn test_ctx() -> RequestContext {
-        RequestContext::new(TaskKind::UnitTest, DownloadBehavior::Error)
-    }
-
    macro_rules! write {
        ($writer:ident, $data:literal) => {{
            $writer
-                .write_buffered(::bytes::Bytes::from_static($data).slice_full(), &test_ctx())
+                .write_buffered(::bytes::Bytes::from_static($data).slice_full())
                .await?;
        }};
    }
@@ -271,13 +158,13 @@ mod tests {
    #[tokio::test]
    async fn test_buffered_writes_only() -> std::io::Result<()> {
        let recorder = RecorderWriter::default();
-        let mut writer = BufferedWriter::new(recorder, BytesMut::with_capacity(2));
+        let mut writer = BufferedWriter::<2, _>::new(recorder);
        write!(writer, b"a");
        write!(writer, b"b");
        write!(writer, b"c");
        write!(writer, b"d");
        write!(writer, b"e");
-        let recorder = writer.flush_and_into_inner(&test_ctx()).await?;
+        let recorder = writer.flush_and_into_inner().await?;
        assert_eq!(
            recorder.writes,
            vec![Vec::from(b"ab"), Vec::from(b"cd"), Vec::from(b"e")]
@@ -288,12 +175,12 @@ mod tests {
    #[tokio::test]
    async fn test_passthrough_writes_only() -> std::io::Result<()> {
        let recorder = RecorderWriter::default();
-        let mut writer = BufferedWriter::new(recorder, BytesMut::with_capacity(2));
+        let mut writer = BufferedWriter::<2, _>::new(recorder);
        write!(writer, b"abc");
        write!(writer, b"de");
        write!(writer, b"");
        write!(writer, b"fghijk");
-        let recorder = writer.flush_and_into_inner(&test_ctx()).await?;
+        let recorder = writer.flush_and_into_inner().await?;
        assert_eq!(
            recorder.writes,
            vec![Vec::from(b"abc"), Vec::from(b"de"), Vec::from(b"fghijk")]
@@ -304,45 +191,16 @@ mod tests {
    #[tokio::test]
    async fn test_passthrough_write_with_nonempty_buffer() -> std::io::Result<()> {
        let recorder = RecorderWriter::default();
-        let mut writer = BufferedWriter::new(recorder, BytesMut::with_capacity(2));
+        let mut writer = BufferedWriter::<2, _>::new(recorder);
        write!(writer, b"a");
        write!(writer, b"bc");
        write!(writer, b"d");
        write!(writer, b"e");
-        let recorder = writer.flush_and_into_inner(&test_ctx()).await?;
+        let recorder = writer.flush_and_into_inner().await?;
        assert_eq!(
            recorder.writes,
            vec![Vec::from(b"a"), Vec::from(b"bc"), Vec::from(b"de")]
        );
        Ok(())
    }
-
-    #[tokio::test]
-    async fn test_write_all_borrowed_always_goes_through_buffer() -> std::io::Result<()> {
-        let ctx = test_ctx();
-        let ctx = &ctx;
-        let recorder = RecorderWriter::default();
-        let mut writer = BufferedWriter::new(recorder, BytesMut::with_capacity(2));
-
-        writer.write_buffered_borrowed(b"abc", ctx).await?;
-        writer.write_buffered_borrowed(b"d", ctx).await?;
-        writer.write_buffered_borrowed(b"e", ctx).await?;
-        writer.write_buffered_borrowed(b"fg", ctx).await?;
-        writer.write_buffered_borrowed(b"hi", ctx).await?;
-        writer.write_buffered_borrowed(b"j", ctx).await?;
-        writer.write_buffered_borrowed(b"klmno", ctx).await?;
-
-        let recorder = writer.flush_and_into_inner(ctx).await?;
-        assert_eq!(
-            recorder.writes,
-            {
-                let expect: &[&[u8]] = &[b"ab", b"cd", b"ef", b"gh", b"ij", b"kl", b"mn", b"o"];
-                expect
-            }
-            .iter()
-            .map(|v| v[..].to_vec())
-            .collect::<Vec<_>>()
-        );
-        Ok(())
-    }
 }
--- a/pageserver/src/walingest.rs
+++ b/pageserver/src/walingest.rs
@@ -1034,7 +1034,7 @@ impl WalIngest {

            let nblocks = modification
                .tline
-                .get_rel_size(src_rel, Version::Modified(modification), ctx)
+                .get_rel_size(src_rel, Version::Modified(modification), true, ctx)
                .await?;
            let dst_rel = RelTag {
                spcnode: tablespace_id,
@@ -1068,7 +1068,13 @@ impl WalIngest {

                let content = modification
                    .tline
-                    .get_rel_page_at_lsn(src_rel, blknum, Version::Modified(modification), ctx)
+                    .get_rel_page_at_lsn(
+                        src_rel,
+                        blknum,
+                        Version::Modified(modification),
+                        true,
+                        ctx,
+                    )
                    .await?;
                modification.put_rel_page_image(dst_rel, blknum, content)?;
                num_blocks_copied += 1;
@@ -1236,7 +1242,7 @@ impl WalIngest {
                };
                if modification
                    .tline
-                    .get_rel_exists(rel, Version::Modified(modification), ctx)
+                    .get_rel_exists(rel, Version::Modified(modification), true, ctx)
                    .await?
                {
                    self.put_rel_drop(modification, rel, ctx).await?;
@@ -1535,7 +1541,7 @@ impl WalIngest {
            nblocks
        } else if !modification
            .tline
-            .get_rel_exists(rel, Version::Modified(modification), ctx)
+            .get_rel_exists(rel, Version::Modified(modification), true, ctx)
            .await?
        {
            // create it with 0 size initially, the logic below will extend it
@@ -1547,7 +1553,7 @@ impl WalIngest {
        } else {
            modification
                .tline
-                .get_rel_size(rel, Version::Modified(modification), ctx)
+                .get_rel_size(rel, Version::Modified(modification), true, ctx)
                .await?
        };

@@ -1644,14 +1650,14 @@ async fn get_relsize(
 ) -> anyhow::Result<BlockNumber> {
    let nblocks = if !modification
        .tline
-        .get_rel_exists(rel, Version::Modified(modification), ctx)
+        .get_rel_exists(rel, Version::Modified(modification), true, ctx)
        .await?
    {
        0
    } else {
        modification
            .tline
-            .get_rel_size(rel, Version::Modified(modification), ctx)
+            .get_rel_size(rel, Version::Modified(modification), true, ctx)
            .await?
    };
    Ok(nblocks)
@@ -1726,29 +1732,29 @@ mod tests {
        // The relation was created at LSN 2, not visible at LSN 1 yet.
        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x10)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x10)), false, &ctx)
                .await?,
            false
        );
        assert!(tline
-            .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x10)), &ctx)
+            .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x10)), false, &ctx)
            .await
            .is_err());
        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            true
        );
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            1
        );
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            3
        );
@@ -1756,46 +1762,46 @@ mod tests {
        // Check page contents at each LSN
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            test_img("foo blk 0 at 2")
        );

        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x30)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x30)), false, &ctx)
                .await?,
            test_img("foo blk 0 at 3")
        );

        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x40)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x40)), false, &ctx)
                .await?,
            test_img("foo blk 0 at 3")
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x40)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x40)), false, &ctx)
                .await?,
            test_img("foo blk 1 at 4")
        );

        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            test_img("foo blk 0 at 3")
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            test_img("foo blk 1 at 4")
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 2, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 2, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            test_img("foo blk 2 at 5")
        );
@@ -1811,19 +1817,19 @@ mod tests {
        // Check reported size and contents after truncation
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x60)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x60)), false, &ctx)
                .await?,
            2
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x60)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x60)), false, &ctx)
                .await?,
            test_img("foo blk 0 at 3")
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x60)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x60)), false, &ctx)
                .await?,
            test_img("foo blk 1 at 4")
        );
@@ -1831,13 +1837,13 @@ mod tests {
        // should still see the truncated block with older LSN
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            3
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 2, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 2, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            test_img("foo blk 2 at 5")
        );
@@ -1850,7 +1856,7 @@ mod tests {
        m.commit(&ctx).await?;
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x68)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x68)), false, &ctx)
                .await?,
            0
        );
@@ -1863,19 +1869,19 @@ mod tests {
        m.commit(&ctx).await?;
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x70)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x70)), false, &ctx)
                .await?,
            2
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x70)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 0, Version::Lsn(Lsn(0x70)), false, &ctx)
                .await?,
            ZERO_PAGE
        );
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x70)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 1, Version::Lsn(Lsn(0x70)), false, &ctx)
                .await?,
            test_img("foo blk 1")
        );
@@ -1888,21 +1894,21 @@ mod tests {
        m.commit(&ctx).await?;
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x80)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x80)), false, &ctx)
                .await?,
            1501
        );
        for blk in 2..1500 {
            assert_eq!(
                tline
-                    .get_rel_page_at_lsn(TESTREL_A, blk, Version::Lsn(Lsn(0x80)), &ctx)
+                    .get_rel_page_at_lsn(TESTREL_A, blk, Version::Lsn(Lsn(0x80)), false, &ctx)
                    .await?,
                ZERO_PAGE
            );
        }
        assert_eq!(
            tline
-                .get_rel_page_at_lsn(TESTREL_A, 1500, Version::Lsn(Lsn(0x80)), &ctx)
+                .get_rel_page_at_lsn(TESTREL_A, 1500, Version::Lsn(Lsn(0x80)), false, &ctx)
                .await?,
            test_img("foo blk 1500")
        );
@@ -1929,13 +1935,13 @@ mod tests {
        // Check that rel exists and size is correct
        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            true
        );
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            1
        );
@@ -1948,7 +1954,7 @@ mod tests {
        // Check that rel is not visible anymore
        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x30)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x30)), false, &ctx)
                .await?,
            false
        );
@@ -1966,13 +1972,13 @@ mod tests {
        // Check that rel exists and size is correct
        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x40)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x40)), false, &ctx)
                .await?,
            true
        );
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x40)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x40)), false, &ctx)
                .await?,
            1
        );
@@ -2005,24 +2011,24 @@ mod tests {
        // The relation was created at LSN 20, not visible at LSN 1 yet.
        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x10)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x10)), false, &ctx)
                .await?,
            false
        );
        assert!(tline
-            .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x10)), &ctx)
+            .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x10)), false, &ctx)
            .await
            .is_err());

        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            true
        );
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x20)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x20)), false, &ctx)
                .await?,
            relsize
        );
@@ -2033,7 +2039,7 @@ mod tests {
            let data = format!("foo blk {} at {}", blkno, lsn);
            assert_eq!(
                tline
-                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(lsn), &ctx)
+                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(lsn), false, &ctx)
                    .await?,
                test_img(&data)
            );
@@ -2050,7 +2056,7 @@ mod tests {
        // Check reported size and contents after truncation
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x60)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x60)), false, &ctx)
                .await?,
            1
        );
@@ -2060,7 +2066,7 @@ mod tests {
            let data = format!("foo blk {} at {}", blkno, lsn);
            assert_eq!(
                tline
-                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(Lsn(0x60)), &ctx)
+                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(Lsn(0x60)), false, &ctx)
                    .await?,
                test_img(&data)
            );
@@ -2069,7 +2075,7 @@ mod tests {
        // should still see all blocks with older LSN
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x50)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x50)), false, &ctx)
                .await?,
            relsize
        );
@@ -2078,7 +2084,7 @@ mod tests {
            let data = format!("foo blk {} at {}", blkno, lsn);
            assert_eq!(
                tline
-                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(Lsn(0x50)), &ctx)
+                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(Lsn(0x50)), false, &ctx)
                    .await?,
                test_img(&data)
            );
@@ -2098,13 +2104,13 @@ mod tests {

        assert_eq!(
            tline
-                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x80)), &ctx)
+                .get_rel_exists(TESTREL_A, Version::Lsn(Lsn(0x80)), false, &ctx)
                .await?,
            true
        );
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x80)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(0x80)), false, &ctx)
                .await?,
            relsize
        );
@@ -2114,7 +2120,7 @@ mod tests {
            let data = format!("foo blk {} at {}", blkno, lsn);
            assert_eq!(
                tline
-                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(Lsn(0x80)), &ctx)
+                    .get_rel_page_at_lsn(TESTREL_A, blkno, Version::Lsn(Lsn(0x80)), false, &ctx)
                    .await?,
                test_img(&data)
            );
@@ -2148,7 +2154,7 @@ mod tests {

        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), false, &ctx)
                .await?,
            RELSEG_SIZE + 1
        );
@@ -2162,7 +2168,7 @@ mod tests {
        m.commit(&ctx).await?;
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), false, &ctx)
                .await?,
            RELSEG_SIZE
        );
@@ -2177,7 +2183,7 @@ mod tests {
        m.commit(&ctx).await?;
        assert_eq!(
            tline
-                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), &ctx)
+                .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), false, &ctx)
                .await?,
            RELSEG_SIZE - 1
        );
@@ -2195,7 +2201,7 @@ mod tests {
            m.commit(&ctx).await?;
            assert_eq!(
                tline
-                    .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), &ctx)
+                    .get_rel_size(TESTREL_A, Version::Lsn(Lsn(lsn)), false, &ctx)
                    .await?,
                size as BlockNumber
            );
--- a/pgxn/neon/Makefile
+++ b/pgxn/neon/Makefile
@@ -14,8 +14,7 @@ OBJS = \
 	relsize_cache.o \
 	walproposer.o \
 	walproposer_pg.o \
-	control_plane_connector.o \
-	walsender_hooks.o
+	control_plane_connector.o

 PG_CPPFLAGS = -I$(libpq_srcdir)
 SHLIB_LINK_INTERNAL = $(libpq)
--- a/pgxn/neon/libpagestore.c
+++ b/pgxn/neon/libpagestore.c
@@ -49,8 +49,6 @@ char	   *neon_auth_token;
 int			readahead_buffer_size = 128;
 int			flush_every_n_requests = 8;

-int         neon_protocol_version = 2;
-
 static int	n_reconnect_attempts = 0;
 static int	max_reconnect_attempts = 60;
 static int	stripe_size;
@@ -381,17 +379,7 @@ pageserver_connect(shardno_t shard_no, int elevel)
 		pfree(msg);
 		return false;
 	}
-	switch (neon_protocol_version)
-	{
-		case 2:
-			query = psprintf("pagestream_v2 %s %s", neon_tenant, neon_timeline);
-			break;
-		case 1:
-			query = psprintf("pagestream %s %s", neon_tenant, neon_timeline);
-			break;
-		default:
-			elog(ERROR, "unexpected neon_protocol_version %d", neon_protocol_version);
-	}
+	query = psprintf("pagestream %s %s", neon_tenant, neon_timeline);
 	ret = PQsendQuery(conn, query);
 	pfree(query);
 	if (ret != 1)
@@ -452,7 +440,7 @@ pageserver_connect(shardno_t shard_no, int elevel)
 		return false;
 	}

-	neon_shard_log(shard_no, LOG, "libpagestore: connected to '%s' with protocol version %d", connstr, neon_protocol_version);
+	neon_shard_log(shard_no, LOG, "libpagestore: connected to '%s'", connstr);
 	page_servers[shard_no].conn = conn;
 	page_servers[shard_no].wes = wes;

@@ -856,16 +844,6 @@ pg_init_libpagestore(void)
 							PGC_USERSET,
 							0,	/* no flags required */
 							NULL, (GucIntAssignHook) &readahead_buffer_resize, NULL);
-	DefineCustomIntVariable("neon.protocol_version",
-							"Version of compute<->page server protocol",
-							NULL,
-							&neon_protocol_version,
-							2, /* use protocol version 2 */
-							1, /* min */
-							2, /* max */
-							PGC_SU_BACKEND,
-							0,	/* no flags required */
-							NULL, NULL, NULL);

 	relsize_hash_init();

--- a/pgxn/neon/neon.c
+++ b/pgxn/neon/neon.c
@@ -34,7 +34,6 @@
 #include "walproposer.h"
 #include "pagestore_client.h"
 #include "control_plane_connector.h"
-#include "walsender_hooks.h"

 PG_MODULE_MAGIC;
 void		_PG_init(void);
@@ -266,6 +265,7 @@ LogicalSlotsMonitorMain(Datum main_arg)
 	}
 }

+
 void
 _PG_init(void)
 {
@@ -279,7 +279,6 @@ _PG_init(void)

 	pg_init_libpagestore();
 	pg_init_walproposer();
-        WalSender_Custom_XLogReaderRoutines = NeonOnDemandXLogReaderRoutines;

 	InitLogicalReplicationMonitor();

--- a/pgxn/neon/neon_walreader.c
+++ b/pgxn/neon/neon_walreader.c
@@ -36,7 +36,10 @@

 static NeonWALReadResult NeonWALReadRemote(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size count, TimeLineID tli);
 static NeonWALReadResult NeonWALReaderReadMsg(NeonWALReader *state);
+static void NeonWALReaderResetRemote(NeonWALReader *state);
 static bool NeonWALReadLocal(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size count, TimeLineID tli);
+static bool neon_wal_segment_open(NeonWALReader *state, XLogSegNo nextSegNo, TimeLineID *tli_p);
+static void neon_wal_segment_close(NeonWALReader *state);
 static bool is_wal_segment_exists(XLogSegNo segno, int segsize,
 								  TimeLineID tli);

@@ -79,9 +82,8 @@ struct NeonWALReader
 	XLogRecPtr	req_lsn;
 	Size		req_len;
 	Size		req_progress;
-	char		donor_conninfo[MAXCONNINFO];
+	WalProposer *wp;			/* we learn donor through walproposer */
 	char		donor_name[64]; /* saved donor safekeeper name for logging */
-	XLogRecPtr	donor_lsn;
 	/* state of connection to safekeeper */
 	NeonWALReaderRemoteState rem_state;
 	WalProposerConn *wp_conn;
@@ -105,7 +107,7 @@ struct NeonWALReader

 /* palloc and initialize NeonWALReader */
 NeonWALReader *
-NeonWALReaderAllocate(int wal_segment_size, XLogRecPtr available_lsn, char *log_prefix)
+NeonWALReaderAllocate(int wal_segment_size, XLogRecPtr available_lsn, WalProposer *wp, char *log_prefix)
 {
 	NeonWALReader *reader;

@@ -121,6 +123,8 @@ NeonWALReaderAllocate(int wal_segment_size, XLogRecPtr available_lsn, char *log_
 	reader->seg.ws_tli = 0;
 	reader->segcxt.ws_segsize = wal_segment_size;

+	reader->wp = wp;
+
 	reader->rem_state = RS_NONE;

 	if (log_prefix)
@@ -200,16 +204,21 @@ NeonWALReadRemote(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size cou
 {
 	if (state->rem_state == RS_NONE)
 	{
-		if (!NeonWALReaderUpdateDonor(state))
+		XLogRecPtr	donor_lsn;
+
+		/* no connection yet; start one */
+		Safekeeper *donor = GetDonor(state->wp, &donor_lsn);
+
+		if (donor == NULL)
 		{
 			snprintf(state->err_msg, sizeof(state->err_msg),
 					 "failed to establish remote connection to fetch WAL: no donor available");
 			return NEON_WALREAD_ERROR;
-
 		}
-		/* no connection yet; start one */
-		nwr_log(LOG, "establishing connection to %s, lsn=%X/%X to fetch WAL", state->donor_name, LSN_FORMAT_ARGS(state->donor_lsn));
-		state->wp_conn = libpqwp_connect_start(state->donor_conninfo);
+		snprintf(state->donor_name, sizeof(state->donor_name), "%s:%s", donor->host, donor->port);
+		nwr_log(LOG, "establishing connection to %s, flush_lsn %X/%X to fetch WAL",
+				state->donor_name, LSN_FORMAT_ARGS(donor_lsn));
+		state->wp_conn = libpqwp_connect_start(donor->conninfo);
 		if (PQstatus(state->wp_conn->pg_conn) == CONNECTION_BAD)
 		{
 			snprintf(state->err_msg, sizeof(state->err_msg),
@@ -242,22 +251,10 @@ NeonWALReadRemote(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size cou
 				{
 					/* connection successfully established */
 					char		start_repl_query[128];
-					term_t		term = pg_atomic_read_u64(&GetWalpropShmemState()->mineLastElectedTerm);

-					/*
-					 * Set elected walproposer's term to pull only data from
-					 * its history. Note: for logical walsender it means we
-					 * might stream WAL not yet committed by safekeepers. It
-					 * would be cleaner to fix this.
-					 *
-					 * mineLastElectedTerm shouldn't be 0 at this point
-					 * because we checked above that donor exists and it
-					 * appears only after successfull election.
-					 */
-					Assert(term > 0);
 					snprintf(start_repl_query, sizeof(start_repl_query),
 							 "START_REPLICATION PHYSICAL %X/%X (term='" UINT64_FORMAT "')",
-							 LSN_FORMAT_ARGS(startptr), term);
+							 LSN_FORMAT_ARGS(startptr), state->wp->propTerm);
 					nwr_log(LOG, "connection to %s to fetch WAL succeeded, running %s",
 							state->donor_name, start_repl_query);
 					if (!libpqwp_send_query(state->wp_conn, start_repl_query))
@@ -407,10 +404,6 @@ NeonWALReadRemote(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size cou
 			state->req_lsn = InvalidXLogRecPtr;
 			state->req_len = 0;
 			state->req_progress = 0;
-
-			/* Update the current segment info. */
-			state->seg.ws_tli = tli;
-
 			return NEON_WALREAD_SUCCESS;
 		}
 	}
@@ -533,7 +526,7 @@ err:
 }

 /* reset remote connection and request in progress */
-void
+static void
 NeonWALReaderResetRemote(NeonWALReader *state)
 {
 	state->req_lsn = InvalidXLogRecPtr;
@@ -698,25 +691,13 @@ NeonWALReadLocal(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size coun
 	return true;
 }

-XLogRecPtr
-NeonWALReaderGetRemLsn(NeonWALReader *state)
-{
-	return state->rem_lsn;
-}
-
-const WALOpenSegment *
-NeonWALReaderGetSegment(NeonWALReader *state)
-{
-	return &state->seg;
-}
-
 /*
 * Copy of vanilla wal_segment_open, but returns false in case of error instead
 * of ERROR, with errno set.
 *
 * XLogReaderRoutine->segment_open callback for local pg_wal files
 */
-bool
+static bool
 neon_wal_segment_open(NeonWALReader *state, XLogSegNo nextSegNo,
 					  TimeLineID *tli_p)
 {
@@ -743,7 +724,7 @@ is_wal_segment_exists(XLogSegNo segno, int segsize, TimeLineID tli)
 }

 /* copy of vanilla wal_segment_close with NeonWALReader */
-void
+static void
 neon_wal_segment_close(NeonWALReader *state)
 {
 	if (state->seg.ws_file >= 0)
@@ -759,19 +740,3 @@ NeonWALReaderErrMsg(NeonWALReader *state)
 {
 	return state->err_msg;
 }
-
-/*
- * Returns true if there is a donor, and false otherwise
- */
-bool
-NeonWALReaderUpdateDonor(NeonWALReader *state)
-{
-	WalproposerShmemState *wps = GetWalpropShmemState();
-
-	SpinLockAcquire(&wps->mutex);
-	memcpy(state->donor_name, wps->donor_name, sizeof(state->donor_name));
-	memcpy(state->donor_conninfo, wps->donor_conninfo, sizeof(state->donor_conninfo));
-	state->donor_lsn = wps->donor_lsn;
-	SpinLockRelease(&wps->mutex);
-	return state->donor_name[0] != '\0';
-}
--- a/pgxn/neon/neon_walreader.h
+++ b/pgxn/neon/neon_walreader.h
@@ -19,19 +19,12 @@ typedef enum
 	NEON_WALREAD_ERROR,
 } NeonWALReadResult;

-extern NeonWALReader *NeonWALReaderAllocate(int wal_segment_size, XLogRecPtr available_lsn, char *log_prefix);
+extern NeonWALReader *NeonWALReaderAllocate(int wal_segment_size, XLogRecPtr available_lsn, WalProposer *wp, char *log_prefix);
 extern void NeonWALReaderFree(NeonWALReader *state);
-extern void NeonWALReaderResetRemote(NeonWALReader *state);
 extern NeonWALReadResult NeonWALRead(NeonWALReader *state, char *buf, XLogRecPtr startptr, Size count, TimeLineID tli);
 extern pgsocket NeonWALReaderSocket(NeonWALReader *state);
 extern uint32 NeonWALReaderEvents(NeonWALReader *state);
 extern bool NeonWALReaderIsRemConnEstablished(NeonWALReader *state);
 extern char *NeonWALReaderErrMsg(NeonWALReader *state);
-extern XLogRecPtr NeonWALReaderGetRemLsn(NeonWALReader *state);
-extern const WALOpenSegment *NeonWALReaderGetSegment(NeonWALReader *state);
-extern bool neon_wal_segment_open(NeonWALReader *state, XLogSegNo nextSegNo, TimeLineID *tli_p);
-extern void neon_wal_segment_close(NeonWALReader *state);
-extern bool NeonWALReaderUpdateDonor(NeonWALReader *state);
-

 #endif							/* __NEON_WALREADER_H__ */
--- a/pgxn/neon/pagestore_client.h
+++ b/pgxn/neon/pagestore_client.h
@@ -69,33 +69,18 @@ typedef enum {
 	SLRU_MULTIXACT_OFFSETS
 } SlruKind;

-/*--
- * supertype of all the Neon*Request structs below.
+/*
+ * supertype of all the Neon*Request structs below
 *
- * All requests contain two LSNs:
- *
- * lsn:                request page (or relation size, etc) at this LSN
- * not_modified_since: Hint that the page hasn't been modified between
- *                     this LSN and the request LSN (`lsn`).
- *
- * To request the latest version of a page, you can use MAX_LSN as the request
- * LSN.
- *
- * If you don't know any better, you can always set 'not_modified_since' equal
- * to 'lsn', but providing a lower value can speed up processing the request
- * in the pageserver, as it doesn't need to wait for the WAL to arrive, and it
- * can skip traversing through recent layers which we know to not contain any
- * versions for the requested page.
- *
- * These structs describe the V2 of these requests. The old V1 protocol contained
- * just one LSN and a boolean 'latest' flag. If the neon_protocol_version GUC is
- * set to 1, we will convert these to the V1 requests before sending.
+ * If 'latest' is true, we are requesting the latest page version, and 'lsn'
+ * is just a hint to the server that we know there are no versions of the page
+ * (or relation size, for exists/nblocks requests) later than the 'lsn'.
 */
 typedef struct
 {
 	NeonMessageTag tag;
-	XLogRecPtr	lsn;
-	XLogRecPtr	not_modified_since;
+	bool		latest;			/* if true, request latest page version */
+	XLogRecPtr	lsn;			/* request page version @ this LSN */
 } NeonRequest;

 typedef struct
@@ -208,7 +193,6 @@ extern int	readahead_buffer_size;
 extern char *neon_timeline;
 extern char *neon_tenant;
 extern int32 max_cluster_size;
-extern int  neon_protocol_version;

 extern shardno_t get_shard_number(BufferTag* tag);

@@ -241,14 +225,14 @@ extern bool neon_prefetch(SMgrRelation reln, ForkNumber forknum,
 extern void neon_read(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 					  char *buffer);
 extern PGDLLEXPORT void neon_read_at_lsn(NRelFileInfo rnode, ForkNumber forkNum, BlockNumber blkno,
-										 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, char *buffer);
+										 XLogRecPtr request_lsn, bool request_latest, char *buffer);
 extern void neon_write(SMgrRelation reln, ForkNumber forknum,
 					   BlockNumber blocknum, char *buffer, bool skipFsync);
 #else
 extern void neon_read(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 					  void *buffer);
 extern PGDLLEXPORT void neon_read_at_lsn(NRelFileInfo rnode, ForkNumber forkNum, BlockNumber blkno,
-										 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, void *buffer);
+										 XLogRecPtr request_lsn, bool request_latest, void *buffer);
 extern void neon_write(SMgrRelation reln, ForkNumber forknum,
 					   BlockNumber blocknum, const void *buffer, bool skipFsync);
 #endif
--- a/pgxn/neon/pagestore_smgr.c
+++ b/pgxn/neon/pagestore_smgr.c
@@ -168,8 +168,8 @@ typedef enum PrefetchStatus
 typedef struct PrefetchRequest
 {
 	BufferTag	buftag;			/* must be first entry in the struct */
-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
+	XLogRecPtr	effective_request_lsn;
+	XLogRecPtr	actual_request_lsn;
 	NeonResponse *response;		/* may be null */
 	PrefetchStatus status;
 	shardno_t   shard_no;
@@ -269,19 +269,19 @@ static PrefetchState *MyPState;
 	) \
 )

+static XLogRecPtr prefetch_lsn = 0;
+
 static bool compact_prefetch_buffers(void);
 static void consume_prefetch_responses(void);
-static uint64 prefetch_register_buffer(BufferTag tag, XLogRecPtr *force_request_lsn, XLogRecPtr *force_not_modified_since);
+static uint64 prefetch_register_buffer(BufferTag tag, bool *force_latest, XLogRecPtr *force_lsn);
 static bool prefetch_read(PrefetchRequest *slot);
-static void prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRecPtr *force_not_modified_since);
+static void prefetch_do_request(PrefetchRequest *slot, bool *force_latest, XLogRecPtr *force_lsn);
 static bool prefetch_wait_for(uint64 ring_index);
 static void prefetch_cleanup_trailing_unused(void);
 static inline void prefetch_set_unused(uint64 ring_index);

-static void neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
-								 XLogRecPtr *request_lsn, XLogRecPtr *not_modified_since);
-static bool neon_prefetch_response_usable(XLogRecPtr request_lsn, XLogRecPtr not_modified_since,
-										  PrefetchRequest *slot);
+static XLogRecPtr neon_get_request_lsn(bool *latest, NRelFileInfo rinfo,
+									   ForkNumber forknum, BlockNumber blkno);

 static bool
 compact_prefetch_buffers(void)
@@ -338,8 +338,8 @@ compact_prefetch_buffers(void)
 		target_slot->shard_no = source_slot->shard_no;
 		target_slot->status = source_slot->status;
 		target_slot->response = source_slot->response;
-		target_slot->request_lsn = source_slot->request_lsn;
-		target_slot->not_modified_since = source_slot->not_modified_since;
+		target_slot->effective_request_lsn = source_slot->effective_request_lsn;
+		target_slot->actual_request_lsn = source_slot->actual_request_lsn;
 		target_slot->my_ring_index = empty_ring_index;

 		prfh_delete(MyPState->prf_hash, source_slot);
@@ -358,8 +358,7 @@ compact_prefetch_buffers(void)
 		};
 		source_slot->response = NULL;
 		source_slot->my_ring_index = 0;
-		source_slot->request_lsn = InvalidXLogRecPtr;
-		source_slot->not_modified_since = InvalidXLogRecPtr;
+		source_slot->effective_request_lsn = 0;

 		/* update bookkeeping */
 		n_moved++;
@@ -684,39 +683,56 @@ prefetch_set_unused(uint64 ring_index)
 		compact_prefetch_buffers();
 }

-/*
- * Send one prefetch request to the pageserver. To wait for the response, call
- * prefetch_wait_for().
- */
 static void
-prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRecPtr *force_not_modified_since)
+prefetch_do_request(PrefetchRequest *slot, bool *force_latest, XLogRecPtr *force_lsn)
 {
 	bool		found;
 	NeonGetPageRequest request = {
 		.req.tag = T_NeonGetPageRequest,
-		/* lsn and not_modified_since are filled in below */
+		.req.latest = false,
+		.req.lsn = 0,
 		.rinfo = BufTagGetNRelFileInfo(slot->buftag),
 		.forknum = slot->buftag.forkNum,
 		.blkno = slot->buftag.blockNum,
 	};

-	Assert(((force_request_lsn != NULL) == (force_not_modified_since != NULL)));
-
-	if (force_request_lsn)
+	if (force_lsn && force_latest)
 	{
-		request.req.lsn = *force_request_lsn;
-		request.req.not_modified_since = *force_not_modified_since;
+		request.req.lsn = *force_lsn;
+		request.req.latest = *force_latest;
+		slot->actual_request_lsn = slot->effective_request_lsn = *force_lsn;
 	}
 	else
 	{
-		neon_get_request_lsn(BufTagGetNRelFileInfo(slot->buftag),
-							 slot->buftag.forkNum,
-							 slot->buftag.blockNum,
-							 &request.req.lsn,
-							 &request.req.not_modified_since);
+		XLogRecPtr	lsn = neon_get_request_lsn(
+											   &request.req.latest,
+											   BufTagGetNRelFileInfo(slot->buftag),
+											   slot->buftag.forkNum,
+											   slot->buftag.blockNum
+			);
+
+		/*
+		 * Note: effective_request_lsn is potentially higher than the
+		 * requested LSN, but still correct:
+		 *
+		 * We know there are no changes between the actual requested LSN and
+		 * the value of effective_request_lsn: If there were, the page would
+		 * have been in cache and evicted between those LSN values, which then
+		 * would have had to result in a larger request LSN for this page.
+		 *
+		 * It is possible that a concurrent backend loads the page, modifies
+		 * it and then evicts it again, but the LSN of that eviction cannot be
+		 * smaller than the current WAL insert/redo pointer, which is already
+		 * larger than this prefetch_lsn. So in any case, that would
+		 * invalidate this cache.
+		 *
+		 * The best LSN to use for effective_request_lsn would be
+		 * XLogCtl->Insert.RedoRecPtr, but that's expensive to access.
+		 */
+		slot->actual_request_lsn = request.req.lsn = lsn;
+		prefetch_lsn = Max(prefetch_lsn, lsn);
+		slot->effective_request_lsn = prefetch_lsn;
 	}
-	slot->request_lsn = request.req.lsn;
-	slot->not_modified_since = request.req.not_modified_since;

 	Assert(slot->response == NULL);
 	Assert(slot->my_ring_index == MyPState->ring_unused);
@@ -733,6 +749,7 @@ prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRe
 	/* update slot state */
 	slot->status = PRFS_REQUESTED;

+
 	prfh_insert(MyPState->prf_hash, slot, &found);
 	Assert(!found);
 }
@@ -742,25 +759,22 @@ prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRe
 *
 * Register that we may want the contents of BufferTag in the near future.
 *
- * If force_request_lsn and force_not_modified_since are not NULL, those
- * values are sent to the pageserver. If they are NULL, we utilize the
- * lastWrittenLsn -infrastructure to fill them in.
+ * If force_latest and force_lsn are not NULL, those values are sent to the
+ * pageserver. If they are NULL, we utilize the lastWrittenLsn -infrastructure
+ * to fill in these values manually.
 *
 * NOTE: this function may indirectly update MyPState->pfs_hash; which
 * invalidates any active pointers into the hash table.
 */

 static uint64
-prefetch_register_buffer(BufferTag tag, XLogRecPtr *force_request_lsn,
-						 XLogRecPtr *force_not_modified_since)
+prefetch_register_buffer(BufferTag tag, bool *force_latest, XLogRecPtr *force_lsn)
 {
 	uint64		ring_index;
 	PrefetchRequest req;
 	PrefetchRequest *slot;
 	PrfHashEntry *entry;

-	Assert(((force_request_lsn != NULL) == (force_not_modified_since != NULL)));
-
 	/* use an intermediate PrefetchRequest struct to ensure correct alignment */
 	req.buftag = tag;
 Retry:
@@ -778,19 +792,40 @@ Retry:
 		Assert(BUFFERTAGS_EQUAL(slot->buftag, tag));

 		/*
-		 * If the caller specified a request LSN to use, only accept prefetch
-		 * responses that satisfy that request.
+		 * If we want a specific lsn, we do not accept requests that were made
+		 * with a potentially different LSN.
 		 */
-		if (force_request_lsn)
+		if (force_latest && force_lsn)
 		{
-			if (!neon_prefetch_response_usable(*force_request_lsn,
-											   *force_not_modified_since, slot))
+			/*
+			 * if we want the latest version, any effective_request_lsn <
+			 * request lsn is OK
+			 */
+			if (*force_latest)
 			{
-				/* Wait for the old request to finish and discard it */
-				if (!prefetch_wait_for(ring_index))
-					goto Retry;
-				prefetch_set_unused(ring_index);
-				entry = NULL;
+				if (*force_lsn > slot->effective_request_lsn)
+				{
+					if (!prefetch_wait_for(ring_index))
+						goto Retry;
+					prefetch_set_unused(ring_index);
+					entry = NULL;
+				}
+
+			}
+
+			/*
+			 * if we don't want the latest version, only accept requests with
+			 * the exact same LSN
+			 */
+			else
+			{
+				if (*force_lsn != slot->effective_request_lsn)
+				{
+					if (!prefetch_wait_for(ring_index))
+						goto Retry;
+					prefetch_set_unused(ring_index);
+					entry = NULL;
+				}
 			}
 		}

@@ -886,7 +921,7 @@ Retry:
 	slot->shard_no = get_shard_number(&tag);
 	slot->my_ring_index = ring_index;

-	prefetch_do_request(slot, force_request_lsn, force_not_modified_since);
+	prefetch_do_request(slot, force_latest, force_lsn);
 	Assert(slot->status == PRFS_REQUESTED);
 	Assert(MyPState->ring_last <= ring_index &&
 		   ring_index < MyPState->ring_unused);
@@ -915,7 +950,7 @@ page_server_request(void const *req)
 	BufferTag tag = {0};
 	shardno_t shard_no;

-	switch (messageTag(req))
+	switch (((NeonRequest *) req)->tag)
 	{
 		case T_NeonExistsRequest:
 			CopyNRelFileInfoToBufTag(tag, ((NeonExistsRequest *) req)->rinfo);
@@ -931,10 +966,11 @@ page_server_request(void const *req)
 			tag.blockNum = ((NeonGetPageRequest *) req)->blkno;
 			break;
 		default:
-			neon_log(ERROR, "Unexpected request tag: %d", messageTag(req));
+			neon_log(ERROR, "Unexpected request tag: %d", ((NeonRequest *) req)->tag);
 	}
 	shard_no = get_shard_number(&tag);

+
 	/*
 	 * Current sharding model assumes that all metadata is present only at shard 0.
 	 * We still need to call get_shard_no() to check if shard map is up-to-date.
@@ -961,52 +997,8 @@ nm_pack_request(NeonRequest *msg)
 	StringInfoData s;

 	initStringInfo(&s);
+	pq_sendbyte(&s, msg->tag);

-	if (neon_protocol_version >= 2)
-	{
-		pq_sendbyte(&s, msg->tag);
-		pq_sendint64(&s, msg->lsn);
-		pq_sendint64(&s, msg->not_modified_since);
-	}
-	else
-	{
-		bool		latest;
-		XLogRecPtr	lsn;
-
-		/*
-		 * In primary, we always request the latest page version.
-		 */
-		if (!RecoveryInProgress())
-		{
-			latest = true;
-			lsn = msg->not_modified_since;
-		}
-		else
-		{
-			/*
-			 * In the protocol V1, we cannot represent that we want to read
-			 * page at LSN X, and we know that it hasn't been modified since
-			 * Y. We can either use 'not_modified_lsn' as the request LSN, and
-			 * risk getting an error if that LSN is too old and has already
-			 * fallen out of the pageserver's GC horizon, or we can send
-			 * 'request_lsn', causing the pageserver to possibly wait for the
-			 * recent WAL to arrive unnecessarily. Or something in between. We
-			 * choose to use the old LSN and risk GC errors, because that's
-			 * what we've done historically.
-			 */
-			latest = false;
-			lsn = msg->not_modified_since;
-		}
-
-		pq_sendbyte(&s, msg->tag);
-		pq_sendbyte(&s, latest);
-		pq_sendint64(&s, lsn);
-	}
-
-	/*
-	 * The rest of the request messages are the same between protocol V1 and
-	 * V2
-	 */
 	switch (messageTag(msg))
 	{
 			/* pagestore_client -> pagestore */
@@ -1014,6 +1006,8 @@ nm_pack_request(NeonRequest *msg)
 			{
 				NeonExistsRequest *msg_req = (NeonExistsRequest *) msg;

+				pq_sendbyte(&s, msg_req->req.latest);
+				pq_sendint64(&s, msg_req->req.lsn);
 				pq_sendint32(&s, NInfoGetSpcOid(msg_req->rinfo));
 				pq_sendint32(&s, NInfoGetDbOid(msg_req->rinfo));
 				pq_sendint32(&s, NInfoGetRelNumber(msg_req->rinfo));
@@ -1025,6 +1019,8 @@ nm_pack_request(NeonRequest *msg)
 			{
 				NeonNblocksRequest *msg_req = (NeonNblocksRequest *) msg;

+				pq_sendbyte(&s, msg_req->req.latest);
+				pq_sendint64(&s, msg_req->req.lsn);
 				pq_sendint32(&s, NInfoGetSpcOid(msg_req->rinfo));
 				pq_sendint32(&s, NInfoGetDbOid(msg_req->rinfo));
 				pq_sendint32(&s, NInfoGetRelNumber(msg_req->rinfo));
@@ -1036,6 +1032,8 @@ nm_pack_request(NeonRequest *msg)
 			{
 				NeonDbSizeRequest *msg_req = (NeonDbSizeRequest *) msg;

+				pq_sendbyte(&s, msg_req->req.latest);
+				pq_sendint64(&s, msg_req->req.lsn);
 				pq_sendint32(&s, msg_req->dbNode);

 				break;
@@ -1044,6 +1042,8 @@ nm_pack_request(NeonRequest *msg)
 			{
 				NeonGetPageRequest *msg_req = (NeonGetPageRequest *) msg;

+				pq_sendbyte(&s, msg_req->req.latest);
+				pq_sendint64(&s, msg_req->req.lsn);
 				pq_sendint32(&s, NInfoGetSpcOid(msg_req->rinfo));
 				pq_sendint32(&s, NInfoGetDbOid(msg_req->rinfo));
 				pq_sendint32(&s, NInfoGetRelNumber(msg_req->rinfo));
@@ -1057,6 +1057,8 @@ nm_pack_request(NeonRequest *msg)
 			{
 				NeonGetSlruSegmentRequest *msg_req = (NeonGetSlruSegmentRequest *) msg;

+				pq_sendbyte(&s, msg_req->req.latest);
+				pq_sendint64(&s, msg_req->req.lsn);
 				pq_sendbyte(&s, msg_req->kind);
 				pq_sendint32(&s, msg_req->segno);

@@ -1207,7 +1209,7 @@ nm_to_string(NeonMessage *msg)
 				appendStringInfo(&s, ", \"rinfo\": \"%u/%u/%u\"", RelFileInfoFmt(msg_req->rinfo));
 				appendStringInfo(&s, ", \"forknum\": %d", msg_req->forknum);
 				appendStringInfo(&s, ", \"lsn\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.lsn));
-				appendStringInfo(&s, ", \"not_modified_since\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.not_modified_since));
+				appendStringInfo(&s, ", \"latest\": %d", msg_req->req.latest);
 				appendStringInfoChar(&s, '}');
 				break;
 			}
@@ -1220,7 +1222,7 @@ nm_to_string(NeonMessage *msg)
 				appendStringInfo(&s, ", \"rinfo\": \"%u/%u/%u\"", RelFileInfoFmt(msg_req->rinfo));
 				appendStringInfo(&s, ", \"forknum\": %d", msg_req->forknum);
 				appendStringInfo(&s, ", \"lsn\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.lsn));
-				appendStringInfo(&s, ", \"not_modified_since\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.not_modified_since));
+				appendStringInfo(&s, ", \"latest\": %d", msg_req->req.latest);
 				appendStringInfoChar(&s, '}');
 				break;
 			}
@@ -1234,7 +1236,7 @@ nm_to_string(NeonMessage *msg)
 				appendStringInfo(&s, ", \"forknum\": %d", msg_req->forknum);
 				appendStringInfo(&s, ", \"blkno\": %u", msg_req->blkno);
 				appendStringInfo(&s, ", \"lsn\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.lsn));
-				appendStringInfo(&s, ", \"not_modified_since\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.not_modified_since));
+				appendStringInfo(&s, ", \"latest\": %d", msg_req->req.latest);
 				appendStringInfoChar(&s, '}');
 				break;
 			}
@@ -1245,7 +1247,7 @@ nm_to_string(NeonMessage *msg)
 				appendStringInfoString(&s, "{\"type\": \"NeonDbSizeRequest\"");
 				appendStringInfo(&s, ", \"dbnode\": \"%u\"", msg_req->dbNode);
 				appendStringInfo(&s, ", \"lsn\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.lsn));
-				appendStringInfo(&s, ", \"not_modified_since\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.not_modified_since));
+				appendStringInfo(&s, ", \"latest\": %d", msg_req->req.latest);
 				appendStringInfoChar(&s, '}');
 				break;
 			}
@@ -1257,7 +1259,7 @@ nm_to_string(NeonMessage *msg)
 				appendStringInfo(&s, ", \"kind\": %u", msg_req->kind);
 				appendStringInfo(&s, ", \"segno\": %u", msg_req->segno);
 				appendStringInfo(&s, ", \"lsn\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.lsn));
-				appendStringInfo(&s, ", \"not_modified_since\": \"%X/%X\"", LSN_FORMAT_ARGS(msg_req->req.not_modified_since));
+				appendStringInfo(&s, ", \"latest\": %d", msg_req->req.latest);
 				appendStringInfoChar(&s, '}');
 				break;
 			}
@@ -1529,38 +1531,44 @@ nm_adjust_lsn(XLogRecPtr lsn)
 /*
 * Return LSN for requesting pages and number of blocks from page server
 */
-static void
-neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
-					 XLogRecPtr *request_lsn, XLogRecPtr *not_modified_since)
+static XLogRecPtr
+neon_get_request_lsn(bool *latest, NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno)
 {
-	XLogRecPtr	last_written_lsn;
-
-	last_written_lsn = GetLastWrittenLSN(rinfo, forknum, blkno);
-	last_written_lsn = nm_adjust_lsn(last_written_lsn);
-	Assert(last_written_lsn != InvalidXLogRecPtr);
+	XLogRecPtr	lsn;

 	if (RecoveryInProgress())
 	{
-		/* Request the page at the last replayed LSN. */
-		*request_lsn = GetXLogReplayRecPtr(NULL);
-		*not_modified_since = last_written_lsn;
-		Assert(last_written_lsn <= *request_lsn);
+		/*
+		 * We don't know if WAL has been generated but not yet replayed, so
+		 * we're conservative in our estimates about latest pages.
+		 */
+		*latest = false;

-		neon_log(DEBUG1, "neon_get_request_lsn request lsn %X/%X, not_modified_since %X/%X",
-				 LSN_FORMAT_ARGS(*request_lsn), LSN_FORMAT_ARGS(*not_modified_since));
+		/*
+		 * Get the last written LSN of this page.
+		 */
+		lsn = GetLastWrittenLSN(rinfo, forknum, blkno);
+		lsn = nm_adjust_lsn(lsn);
+
+		neon_log(DEBUG1, "neon_get_request_lsn GetXLogReplayRecPtr %X/%X request lsn 0 ",
+			 (uint32) ((lsn) >> 32), (uint32) (lsn));
 	}
 	else
 	{
 		XLogRecPtr	flushlsn;

 		/*
-		 * Use the latest LSN that was evicted from the buffer cache as the
-		 * 'not_modified_since' hint. Any pages modified by later WAL records
-		 * must still in the buffer cache, so our request cannot concern
-		 * those.
+		 * Use the latest LSN that was evicted from the buffer cache. Any
+		 * pages modified by later WAL records must still in the buffer cache,
+		 * so our request cannot concern those.
 		 */
+		*latest = true;
+		lsn = GetLastWrittenLSN(rinfo, forknum, blkno);
+		Assert(lsn != InvalidXLogRecPtr);
 		neon_log(DEBUG1, "neon_get_request_lsn GetLastWrittenLSN lsn %X/%X ",
-				 LSN_FORMAT_ARGS(last_written_lsn));
+			 (uint32) ((lsn) >> 32), (uint32) (lsn));
+
+		lsn = nm_adjust_lsn(lsn);

 		/*
 		 * Is it possible that the last-written LSN is ahead of last flush
@@ -1575,109 +1583,16 @@ neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 #else
 		flushlsn = GetFlushRecPtr();
 #endif
-		if (last_written_lsn > flushlsn)
+		if (lsn > flushlsn)
 		{
 			neon_log(DEBUG5, "last-written LSN %X/%X is ahead of last flushed LSN %X/%X",
-					 LSN_FORMAT_ARGS(last_written_lsn),
-					 LSN_FORMAT_ARGS(flushlsn));
-			XLogFlush(last_written_lsn);
-			flushlsn = last_written_lsn;
+				 (uint32) (lsn >> 32), (uint32) lsn,
+				 (uint32) (flushlsn >> 32), (uint32) flushlsn);
+			XLogFlush(lsn);
 		}
-
-		/*
-		 * Request the latest version of the page. The most up-to-date request
-		 * LSN we could use would be the current insert LSN, but to avoid the
-		 * overhead of looking it up, use 'flushlsn' instead. This relies on
-		 * the assumption that if the page was modified since the last WAL
-		 * flush, it should still be in the buffer cache, and we wouldn't be
-		 * requesting it.
-		 */
-		*request_lsn = flushlsn;
-		*not_modified_since = last_written_lsn;
-	}
-}
-
-/*
- *  neon_prefetch_response_usable -- Can a new request be satisfied by old one?
- *
- * This is used to check if the response to a prefetch request can be used to
- * satisfy a page read now.
- */
-static bool
-neon_prefetch_response_usable(XLogRecPtr request_lsn, XLogRecPtr not_modified_since,
-							  PrefetchRequest *slot)
-{
-	/* sanity check the LSN's on the old and the new request */
-	Assert(request_lsn >= not_modified_since);
-	Assert(slot->request_lsn >= slot->not_modified_since);
-	Assert(slot->status != PRFS_UNUSED);
-
-	/*
-	 * The new request's LSN should never be older than the old one.  This
-	 * could be an Assert, except that for testing purposes, we do provide an
-	 * interface in neon_test_utils to fetch pages at arbitary LSNs, which
-	 * violates this.
-	 *
-	 * Similarly, the not_modified_since value calculated for a page should
-	 * never move backwards. This assumption is a bit fragile; if we updated
-	 * the last-written cache when we read in a page, for example, then it
-	 * might. But as the code stands, it should not.
-	 *
-	 * (If two backends issue a request at the same time, they might race and
-	 * calculate LSNs "out of order" with each other, but the prefetch queue
-	 * is backend-private at the moment.)
-	 */
-	if (request_lsn < slot->request_lsn || not_modified_since < slot->not_modified_since)
-	{
-		ereport(LOG,
-				(errcode(ERRCODE_IO_ERROR),
-				 errmsg(NEON_TAG "request with unexpected LSN after prefetch"),
-				 errdetail("Request %X/%X not_modified_since %X/%X, prefetch %X/%X not_modified_since %X/%X)",
-						   LSN_FORMAT_ARGS(request_lsn), LSN_FORMAT_ARGS(not_modified_since),
-						   LSN_FORMAT_ARGS(slot->request_lsn), LSN_FORMAT_ARGS(slot->not_modified_since))));
-		return false;
 	}

-	/*---
-	 * Each request to the pageserver carries two LSN values:
-	 * `not_modified_since` and `request_lsn`. The (not_modified_since,
-	 * request_lsn] range of each request is effectively a claim that the page
-	 * has not been modified between those LSNs.  If the range of the old
-	 * request in the queue overlaps with the new request, we know that the
-	 * page hasn't been modified in the union of the ranges. We can use the
-	 * response to old request to satisfy the new request in that case. For
-	 * example:
-	 *
-	 *              100      500
-	 * Old request:  +--------+
-	 *
-	 *                     400      800
-	 * New request:         +--------+
-	 *
-	 * The old request claims that the page was not modified between LSNs 100
-	 * and 500, and the second claims that it was not modified between 400 and
-	 * 800. Together they mean that the page was not modified between 100 and
-	 * 800. Therefore the response to the old request is also valid for the
-	 * new request.
-	 *
-	 * This logic also holds at the boundary case that the old request's LSN
-	 * matches the new request's not_modified_since LSN exactly:
-	 *
-	 *              100      500
-	 * Old request:  +--------+
-	 *
-	 *                       500      900
-	 * New request:           +--------+
-	 *
-	 * The response to the old request is the page as it was at LSN 500, and
-	 * the page hasn't been changed in the range (500, 900], therefore the
-	 * response is valid also for the new request.
-	 */
-
-	/* this follows from the checks above */
-	Assert(request_lsn >= slot->not_modified_since);
-
-	return not_modified_since <= slot->request_lsn;
+	return lsn;
 }

 /*
@@ -1689,8 +1604,8 @@ neon_exists(SMgrRelation reln, ForkNumber forkNum)
 	bool		exists;
 	NeonResponse *resp;
 	BlockNumber n_blocks;
+	bool		latest;
 	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;

 	switch (reln->smgr_relpersistence)
 	{
@@ -1745,13 +1660,12 @@ neon_exists(SMgrRelation reln, ForkNumber forkNum)
 		return false;
 	}

-	neon_get_request_lsn(InfoFromSMgrRel(reln), forkNum, REL_METADATA_PSEUDO_BLOCKNO,
-						 &request_lsn, &not_modified_since);
+	request_lsn = neon_get_request_lsn(&latest, InfoFromSMgrRel(reln), forkNum, REL_METADATA_PSEUDO_BLOCKNO);
 	{
 		NeonExistsRequest request = {
 			.req.tag = T_NeonExistsRequest,
+			.req.latest = latest,
 			.req.lsn = request_lsn,
-			.req.not_modified_since = not_modified_since,
 			.rinfo = InfoFromSMgrRel(reln),
 		.forknum = forkNum};

@@ -2188,10 +2102,10 @@ neon_writeback(SMgrRelation reln, ForkNumber forknum,
 void
 #if PG_MAJORVERSION_NUM < 16
 neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-				 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, char *buffer)
+				 XLogRecPtr request_lsn, bool request_latest, char *buffer)
 #else
 neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-				 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, void *buffer)
+				 XLogRecPtr request_lsn, bool request_latest, void *buffer)
 #endif
 {
 	NeonResponse *resp;
@@ -2234,16 +2148,15 @@ neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
 	if (entry != NULL)
 	{
 		slot = entry->slot;
-		if (neon_prefetch_response_usable(request_lsn, not_modified_since, slot))
+		if (slot->effective_request_lsn >= request_lsn)
 		{
 			ring_index = slot->my_ring_index;
 			pgBufferUsage.prefetch.hits += 1;
 		}
-		else
+		else					/* the current prefetch LSN is not large
+								 * enough, so drop the prefetch */
 		{
 			/*
-			 * Cannot use this prefetch, discard it
-			 *
 			 * We can't drop cache for not-yet-received requested items. It is
 			 * unlikely this happens, but it can happen if prefetch distance
 			 * is large enough and a backend didn't consume all prefetch
@@ -2268,8 +2181,8 @@ neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
 		{
 			pgBufferUsage.prefetch.misses += 1;

-			ring_index = prefetch_register_buffer(buftag, &request_lsn,
-												  &not_modified_since);
+			ring_index = prefetch_register_buffer(buftag, &request_latest,
+												  &request_lsn);
 			slot = GetPrfSlot(ring_index);
 		}
 		else
@@ -2333,8 +2246,8 @@ neon_read(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno, char *buffer
 neon_read(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno, void *buffer)
 #endif
 {
+	bool		latest;
 	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;

 	switch (reln->smgr_relpersistence)
 	{
@@ -2359,9 +2272,8 @@ neon_read(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno, void *buffer
 		return;
 	}

-	neon_get_request_lsn(InfoFromSMgrRel(reln), forkNum, blkno,
-						 &request_lsn, &not_modified_since);
-	neon_read_at_lsn(InfoFromSMgrRel(reln), forkNum, blkno, request_lsn, not_modified_since, buffer);
+	request_lsn = neon_get_request_lsn(&latest, InfoFromSMgrRel(reln), forkNum, blkno);
+	neon_read_at_lsn(InfoFromSMgrRel(reln), forkNum, blkno, request_lsn, latest, buffer);

 #ifdef DEBUG_COMPARE_LOCAL
 	if (forkNum == MAIN_FORKNUM && IS_LOCAL_REL(reln))
@@ -2530,8 +2442,8 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 {
 	NeonResponse *resp;
 	BlockNumber n_blocks;
+	bool		latest;
 	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;

 	switch (reln->smgr_relpersistence)
 	{
@@ -2558,13 +2470,12 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 		return n_blocks;
 	}

-	neon_get_request_lsn(InfoFromSMgrRel(reln), forknum, REL_METADATA_PSEUDO_BLOCKNO,
-						 &request_lsn, &not_modified_since);
+	request_lsn = neon_get_request_lsn(&latest, InfoFromSMgrRel(reln), forknum, REL_METADATA_PSEUDO_BLOCKNO);
 	{
 		NeonNblocksRequest request = {
 			.req.tag = T_NeonNblocksRequest,
+			.req.latest = latest,
 			.req.lsn = request_lsn,
-			.req.not_modified_since = not_modified_since,
 			.rinfo = InfoFromSMgrRel(reln),
 			.forknum = forknum,
 		};
@@ -2612,17 +2523,16 @@ neon_dbsize(Oid dbNode)
 {
 	NeonResponse *resp;
 	int64		db_size;
-	XLogRecPtr	request_lsn,
-				not_modified_since;
+	XLogRecPtr	request_lsn;
+	bool		latest;
 	NRelFileInfo dummy_node = {0};

-	neon_get_request_lsn(dummy_node, MAIN_FORKNUM, REL_METADATA_PSEUDO_BLOCKNO,
-						 &request_lsn, &not_modified_since);
+	request_lsn = neon_get_request_lsn(&latest, dummy_node, MAIN_FORKNUM, REL_METADATA_PSEUDO_BLOCKNO);
 	{
 		NeonDbSizeRequest request = {
 			.req.tag = T_NeonDbSizeRequest,
+			.req.latest = latest,
 			.req.lsn = request_lsn,
-			.req.not_modified_since = not_modified_since,
 			.dbNode = dbNode,
 		};

@@ -2695,6 +2605,7 @@ neon_truncate(SMgrRelation reln, ForkNumber forknum, BlockNumber nblocks)
 	 * the most recently inserted WAL record's LSN.
 	 */
 	lsn = GetXLogInsertRecPtr();
+
 	lsn = nm_adjust_lsn(lsn);

 	/*
@@ -2894,33 +2805,14 @@ neon_end_unlogged_build(SMgrRelation reln)
 static int
 neon_read_slru_segment(SMgrRelation reln, const char* path, int segno, void* buffer)
 {
-	XLogRecPtr request_lsn,
-		not_modified_since;
-
-	if (RecoveryInProgress())
-	{
-		request_lsn = GetXLogReplayRecPtr(NULL);
-		if (request_lsn == InvalidXLogRecPtr)
-		{
-			/*
-			 * This happens in neon startup, we start up without replaying any
-			 * records.
-			 */
-			request_lsn = GetRedoStartLsn();
-		}
-	}
-	else
-		request_lsn = GetXLogInsertRecPtr();
-	request_lsn = nm_adjust_lsn(request_lsn);
-
+	XLogRecPtr request_lsn;
 	/*
-	 * GetRedoStartLsn() returns LSN of basebackup. We know that the SLRU
-	 * segment has not changed since the basebackup, because in order to
-	 * modify it, we would have had to download it already. And once
-	 * downloaded, we never evict SLRU segments from local disk.
+	 * GetRedoStartLsn() returns LSN of basebackup.
+	 * We need to download SLRU segments only once after node startup,
+	 * then SLRUs are maintained locally.
 	 */
-	not_modified_since = GetRedoStartLsn();
-
+	request_lsn = GetRedoStartLsn();
+	request_lsn = nm_adjust_lsn(request_lsn);
 	SlruKind kind;

    if (STRPREFIX(path, "pg_xact"))
@@ -2935,8 +2827,8 @@ neon_read_slru_segment(SMgrRelation reln, const char* path, int segno, void* buf
 	NeonResponse *resp;
 	NeonGetSlruSegmentRequest request = {
 		.req.tag = T_NeonGetSlruSegmentRequest,
+		.req.latest = false,
 		.req.lsn = request_lsn,
-		.req.not_modified_since = not_modified_since,

 		.kind = kind,
 		.segno = segno
@@ -3064,9 +2956,6 @@ neon_extend_rel_size(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 {
 	BlockNumber relsize;

-	/* This is only used in WAL replay */
-	Assert(RecoveryInProgress());
-
 	/* Extend the relation if we know its size */
 	if (get_cached_relsize(rinfo, forknum, &relsize))
 	{
@@ -3085,13 +2974,14 @@ neon_extend_rel_size(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 		 * This length is later reused when we open the smgr to read the
 		 * block, which is fine and expected.
 		 */
+
 		NeonResponse *response;
 		NeonNblocksResponse *nbresponse;
 		NeonNblocksRequest request = {
 			.req = (NeonRequest) {
-				.tag = T_NeonNblocksRequest,
 				.lsn = end_recptr,
-				.not_modified_since = end_recptr,
+				.latest = false,
+				.tag = T_NeonNblocksRequest,
 			},
 			.rinfo = rinfo,
 			.forknum = forknum,
--- a/pgxn/neon/walproposer.c
+++ b/pgxn/neon/walproposer.c
@@ -80,7 +80,7 @@ static int	CompareLsn(const void *a, const void *b);
 static char *FormatSafekeeperState(Safekeeper *sk);
 static void AssertEventsOkForState(uint32 events, Safekeeper *sk);
 static char *FormatEvents(WalProposer *wp, uint32 events);
-static void UpdateDonorShmem(WalProposer *wp);
+

 WalProposer *
 WalProposerCreate(WalProposerConfig *config, walproposer_api api)
@@ -922,8 +922,7 @@ static void
 DetermineEpochStartLsn(WalProposer *wp)
 {
 	TermHistory *dth;
-	int			n_ready = 0;
-	WalproposerShmemState *walprop_shared;
+	int          n_ready = 0;

 	wp->propEpochStartLsn = InvalidXLogRecPtr;
 	wp->donorEpoch = 0;
@@ -965,18 +964,16 @@ DetermineEpochStartLsn(WalProposer *wp)
 	if (n_ready < wp->quorum)
 	{
 		/*
-		 * This is a rare case that can be triggered if safekeeper has voted
-		 * and disconnected. In this case, its state will not be SS_IDLE and
-		 * its vote cannot be used, because we clean up `voteResponse` in
-		 * `ShutdownConnection`.
+		 * This is a rare case that can be triggered if safekeeper has voted and disconnected.
+		 * In this case, its state will not be SS_IDLE and its vote cannot be used, because
+		 * we clean up `voteResponse` in `ShutdownConnection`.
 		 */
 		wp_log(FATAL, "missing majority of votes, collected %d, expected %d, got %d", wp->n_votes, wp->quorum, n_ready);
 	}

 	/*
-	 * If propEpochStartLsn is 0, it means flushLsn is 0 everywhere, we are
-	 * bootstrapping and nothing was committed yet. Start streaming then from
-	 * the basebackup LSN.
+	 * If propEpochStartLsn is 0, it means flushLsn is 0 everywhere, we are bootstrapping
+	 * and nothing was committed yet. Start streaming then from the basebackup LSN.
 	 */
 	if (wp->propEpochStartLsn == InvalidXLogRecPtr && !wp->config->syncSafekeepers)
 	{
@@ -987,12 +984,11 @@ DetermineEpochStartLsn(WalProposer *wp)
 		}
 		wp_log(LOG, "bumped epochStartLsn to the first record %X/%X", LSN_FORMAT_ARGS(wp->propEpochStartLsn));
 	}
-	pg_atomic_write_u64(&wp->api.get_shmem_state(wp)->propEpochStartLsn, wp->propEpochStartLsn);

 	/*
-	 * Safekeepers are setting truncateLsn after timelineStartLsn is known, so
-	 * it should never be zero at this point, if we know timelineStartLsn.
-	 *
+	 * Safekeepers are setting truncateLsn after timelineStartLsn is known, so it
+	 * should never be zero at this point, if we know timelineStartLsn.
+	 * 
 	 * timelineStartLsn can be zero only on the first syncSafekeepers run.
 	 */
 	Assert((wp->truncateLsn != InvalidXLogRecPtr) ||
@@ -1026,9 +1022,10 @@ DetermineEpochStartLsn(WalProposer *wp)
 	 * since which we are going to write according to the consensus. If not,
 	 * we must bail out, as clog and other non rel data is inconsistent.
 	 */
-	walprop_shared = wp->api.get_shmem_state(wp);
 	if (!wp->config->syncSafekeepers)
 	{
+		WalproposerShmemState *walprop_shared = wp->api.get_shmem_state(wp);
+
 		/*
 		 * Basebackup LSN always points to the beginning of the record (not
 		 * the page), as StartupXLOG most probably wants it this way.
@@ -1043,7 +1040,7 @@ DetermineEpochStartLsn(WalProposer *wp)
 			 * compute (who could generate WAL) is ok.
 			 */
 			if (!((dth->n_entries >= 1) && (dth->entries[dth->n_entries - 1].term ==
-											pg_atomic_read_u64(&walprop_shared->mineLastElectedTerm))))
+											walprop_shared->mineLastElectedTerm)))
 			{
 				/*
 				 * Panic to restart PG as we need to retake basebackup.
@@ -1057,8 +1054,8 @@ DetermineEpochStartLsn(WalProposer *wp)
 					   LSN_FORMAT_ARGS(wp->api.get_redo_start_lsn(wp)));
 			}
 		}
+		walprop_shared->mineLastElectedTerm = wp->propTerm;
 	}
-	pg_atomic_write_u64(&walprop_shared->mineLastElectedTerm, wp->propTerm);
 }

 /*
@@ -1108,13 +1105,9 @@ SendProposerElected(Safekeeper *sk)
 	{
 		/* safekeeper is empty or no common point, start from the beginning */
 		sk->startStreamingAt = wp->propTermHistory.entries[0].lsn;
-		wp_log(LOG, "no common point with sk %s:%s, streaming since first term at %X/%X, timelineStartLsn=%X/%X, termHistory.n_entries=%u",
-			   sk->host, sk->port, LSN_FORMAT_ARGS(sk->startStreamingAt), LSN_FORMAT_ARGS(wp->timelineStartLsn), wp->propTermHistory.n_entries);
-
-		/*
-		 * wp->timelineStartLsn == InvalidXLogRecPtr can be only when timeline
-		 * is created manually (test_s3_wal_replay)
-		 */
+		wp_log(LOG, "no common point with sk %s:%s, streaming since first term at %X/%X, timelineStartLsn=%X/%X, termHistory.n_entries=%u" ,
+		 	 sk->host, sk->port, LSN_FORMAT_ARGS(sk->startStreamingAt), LSN_FORMAT_ARGS(wp->timelineStartLsn), wp->propTermHistory.n_entries);
+		/* wp->timelineStartLsn == InvalidXLogRecPtr can be only when timeline is created manually (test_s3_wal_replay) */
 		Assert(sk->startStreamingAt == wp->timelineStartLsn || wp->timelineStartLsn == InvalidXLogRecPtr);
 	}
 	else
@@ -1184,12 +1177,6 @@ StartStreaming(Safekeeper *sk)
 	sk->active_state = SS_ACTIVE_SEND;
 	sk->streamingAt = sk->startStreamingAt;

-	/*
-	 * Donors can only be in SS_ACTIVE state, so we potentially update the
-	 * donor when we switch one to SS_ACTIVE.
-	 */
-	UpdateDonorShmem(sk->wp);
-
 	/* event set will be updated inside SendMessageToNode */
 	SendMessageToNode(sk);
 }
@@ -1581,17 +1568,17 @@ GetAcknowledgedByQuorumWALPosition(WalProposer *wp)
 * none if it doesn't exist. donor_lsn is set to end position of the donor to
 * the best of our knowledge.
 */
-static void
-UpdateDonorShmem(WalProposer *wp)
+Safekeeper *
+GetDonor(WalProposer *wp, XLogRecPtr *donor_lsn)
 {
 	Safekeeper *donor = NULL;
 	int			i;
-	XLogRecPtr	donor_lsn = InvalidXLogRecPtr;
+	*donor_lsn = InvalidXLogRecPtr;

 	if (wp->n_votes < wp->quorum)
 	{
-		wp_log(WARNING, "UpdateDonorShmem called before elections are won");
-		return;
+		wp_log(WARNING, "GetDonor called before elections are won");
+		return NULL;
 	}

 	/*
@@ -1602,7 +1589,7 @@ UpdateDonorShmem(WalProposer *wp)
 	if (wp->safekeeper[wp->donor].state >= SS_IDLE)
 	{
 		donor = &wp->safekeeper[wp->donor];
-		donor_lsn = wp->propEpochStartLsn;
+		*donor_lsn = wp->propEpochStartLsn;
 	}

 	/*
@@ -1614,19 +1601,13 @@ UpdateDonorShmem(WalProposer *wp)
 	{
 		Safekeeper *sk = &wp->safekeeper[i];

-		if (sk->state == SS_ACTIVE && sk->appendResponse.flushLsn > donor_lsn)
+		if (sk->state == SS_ACTIVE && sk->appendResponse.flushLsn > *donor_lsn)
 		{
 			donor = sk;
-			donor_lsn = sk->appendResponse.flushLsn;
+			*donor_lsn = sk->appendResponse.flushLsn;
 		}
 	}
-
-	if (donor == NULL)
-	{
-		wp_log(WARNING, "UpdateDonorShmem didn't find a suitable donor, skipping");
-		return;
-	}
-	wp->api.update_donor(wp, donor, donor_lsn);
+	return donor;
 }

 /*
@@ -1636,7 +1617,7 @@ static void
 HandleSafekeeperResponse(WalProposer *wp, Safekeeper *sk)
 {
 	XLogRecPtr	candidateTruncateLsn;
-	XLogRecPtr	newCommitLsn;
+	XLogRecPtr  newCommitLsn;

 	newCommitLsn = GetAcknowledgedByQuorumWALPosition(wp);
 	if (newCommitLsn > wp->commitLsn)
@@ -1646,7 +1627,7 @@ HandleSafekeeperResponse(WalProposer *wp, Safekeeper *sk)
 		BroadcastAppendRequest(wp);
 	}

-	/*
+	/* 
 	 * Unlock syncrep waiters, update ps_feedback, CheckGracefulShutdown().
 	 * The last one will terminate the process if the shutdown is requested
 	 * and WAL is committed by the quorum. BroadcastAppendRequest() should be
--- a/pgxn/neon/walproposer.h
+++ b/pgxn/neon/walproposer.h
@@ -284,19 +284,14 @@ typedef struct PageserverFeedback

 typedef struct WalproposerShmemState
 {
-	pg_atomic_uint64 propEpochStartLsn;
-	char		donor_name[64];
-	char		donor_conninfo[MAXCONNINFO];
-	XLogRecPtr	donor_lsn;
-
 	slock_t		mutex;
-	pg_atomic_uint64 mineLastElectedTerm;
+	term_t		mineLastElectedTerm;
 	pg_atomic_uint64 backpressureThrottlingTime;
 	pg_atomic_uint64 currentClusterSize;

 	/* last feedback from each shard */
 	PageserverFeedback shard_ps_feedback[MAX_SHARDS];
-	int			num_shards;
+	int num_shards;

 	/* aggregated feedback with min LSNs across shards */
 	PageserverFeedback min_ps_feedback;
@@ -470,9 +465,6 @@ typedef struct walproposer_api
 	/* Get pointer to the latest available WAL. */
 	XLogRecPtr	(*get_flush_rec_ptr) (WalProposer *wp);

-	/* Update current donor info in WalProposer Shmem */
-	void		(*update_donor) (WalProposer *wp, Safekeeper *donor, XLogRecPtr donor_lsn);
-
 	/* Get current time. */
 	TimestampTz (*get_current_timestamp) (WalProposer *wp);

@@ -505,7 +497,7 @@ typedef struct walproposer_api
 	 *
 	 * On success, the data is placed in *buf. It is valid until the next call
 	 * to this function.
-	 *
+	 * 
 	 * Returns PG_ASYNC_READ_FAIL on closed connection.
 	 */
 	PGAsyncReadResult (*conn_async_read) (Safekeeper *sk, char **buf, int *amount);
@@ -553,14 +545,13 @@ typedef struct walproposer_api
 	 * Returns 0 if timeout is reached, 1 if some event happened. Updates
 	 * events mask to indicate events and sets sk to the safekeeper which has
 	 * an event.
-	 *
+	 * 
 	 * On timeout, events is set to WL_NO_EVENTS. On socket event, events is
 	 * set to WL_SOCKET_READABLE and/or WL_SOCKET_WRITEABLE. When socket is
 	 * closed, events is set to WL_SOCKET_READABLE.
-	 *
-	 * WL_SOCKET_WRITEABLE is usually set only when we need to flush the
-	 * buffer. It can be returned only if caller asked for this event in the
-	 * last *_event_set call.
+	 * 
+	 * WL_SOCKET_WRITEABLE is usually set only when we need to flush the buffer.
+	 * It can be returned only if caller asked for this event in the last *_event_set call.
 	 */
 	int			(*wait_event_set) (WalProposer *wp, long timeout, Safekeeper **sk, uint32 *events);

@@ -580,9 +571,9 @@ typedef struct walproposer_api
 	void		(*finish_sync_safekeepers) (WalProposer *wp, XLogRecPtr lsn);

 	/*
-	 * Called after every AppendResponse from the safekeeper. Used to
-	 * propagate backpressure feedback and to confirm WAL persistence (has
-	 * been commited on the quorum of safekeepers).
+	 * Called after every AppendResponse from the safekeeper. Used to propagate
+	 * backpressure feedback and to confirm WAL persistence (has been commited
+	 * on the quorum of safekeepers).
 	 */
 	void		(*process_safekeeper_feedback) (WalProposer *wp, Safekeeper *sk);

@@ -725,14 +716,12 @@ extern void WalProposerBroadcast(WalProposer *wp, XLogRecPtr startpos, XLogRecPt
 extern void WalProposerPoll(WalProposer *wp);
 extern void WalProposerFree(WalProposer *wp);

-extern WalproposerShmemState *GetWalpropShmemState();
-
 /*
 * WaitEventSet API doesn't allow to remove socket, so walproposer_pg uses it to
 * recreate set from scratch, hence the export.
 */
 extern void SafekeeperStateDesiredEvents(Safekeeper *sk, uint32 *sk_events, uint32 *nwr_events);
-extern TimeLineID walprop_pg_get_timeline_id(void);
+extern Safekeeper *GetDonor(WalProposer *wp, XLogRecPtr *donor_lsn);


 #define WPEVENT		1337		/* special log level for walproposer internal
--- a/pgxn/neon/walproposer_pg.c
+++ b/pgxn/neon/walproposer_pg.c
@@ -85,6 +85,7 @@ static void walprop_pg_init_standalone_sync_safekeepers(void);
 static void walprop_pg_init_walsender(void);
 static void walprop_pg_init_bgworker(void);
 static TimestampTz walprop_pg_get_current_timestamp(WalProposer *wp);
+static TimeLineID walprop_pg_get_timeline_id(void);
 static void walprop_pg_load_libpqwalreceiver(void);

 static process_interrupts_callback_t PrevProcessInterruptsCallback;
@@ -93,8 +94,6 @@ static shmem_startup_hook_type prev_shmem_startup_hook_type;
 static shmem_request_hook_type prev_shmem_request_hook = NULL;
 static void walproposer_shmem_request(void);
 #endif
-static void WalproposerShmemInit_SyncSafekeeper(void);
-

 static void StartProposerReplication(WalProposer *wp, StartReplicationCmd *cmd);
 static void WalSndLoop(WalProposer *wp);
@@ -137,7 +136,6 @@ WalProposerSync(int argc, char *argv[])
 	WalProposer *wp;

 	init_walprop_config(true);
-	WalproposerShmemInit_SyncSafekeeper();
 	walprop_pg_init_standalone_sync_safekeepers();
 	walprop_pg_load_libpqwalreceiver();

@@ -283,8 +281,6 @@ WalproposerShmemInit(void)
 	{
 		memset(walprop_shared, 0, WalproposerShmemSize());
 		SpinLockInit(&walprop_shared->mutex);
-		pg_atomic_init_u64(&walprop_shared->propEpochStartLsn, 0);
-		pg_atomic_init_u64(&walprop_shared->mineLastElectedTerm, 0);
 		pg_atomic_init_u64(&walprop_shared->backpressureThrottlingTime, 0);
 		pg_atomic_init_u64(&walprop_shared->currentClusterSize, 0);
 	}
@@ -293,17 +289,6 @@ WalproposerShmemInit(void)
 	return found;
 }

-static void
-WalproposerShmemInit_SyncSafekeeper(void)
-{
-	walprop_shared = palloc(WalproposerShmemSize());
-	memset(walprop_shared, 0, WalproposerShmemSize());
-	SpinLockInit(&walprop_shared->mutex);
-	pg_atomic_init_u64(&walprop_shared->propEpochStartLsn, 0);
-	pg_atomic_init_u64(&walprop_shared->mineLastElectedTerm, 0);
-	pg_atomic_init_u64(&walprop_shared->backpressureThrottlingTime, 0);
-}
-
 #define BACK_PRESSURE_DELAY 10000L // 0.01 sec

 static bool
@@ -414,13 +399,6 @@ nwp_shmem_startup_hook(void)
 	WalproposerShmemInit();
 }

-WalproposerShmemState *
-GetWalpropShmemState()
-{
-	Assert(walprop_shared != NULL);
-	return walprop_shared;
-}
-
 static WalproposerShmemState *
 walprop_pg_get_shmem_state(WalProposer *wp)
 {
@@ -453,15 +431,14 @@ record_pageserver_feedback(PageserverFeedback *ps_feedback)
 	for (int i = 0; i < walprop_shared->num_shards; i++)
 	{
 		PageserverFeedback *feedback = &walprop_shared->shard_ps_feedback[i];
-
 		if (feedback->present)
 		{
 			if (min_feedback.last_received_lsn == InvalidXLogRecPtr || feedback->last_received_lsn < min_feedback.last_received_lsn)
 				min_feedback.last_received_lsn = feedback->last_received_lsn;
-
+			
 			if (min_feedback.disk_consistent_lsn == InvalidXLogRecPtr || feedback->disk_consistent_lsn < min_feedback.disk_consistent_lsn)
 				min_feedback.disk_consistent_lsn = feedback->disk_consistent_lsn;
-
+			
 			if (min_feedback.remote_consistent_lsn == InvalidXLogRecPtr || feedback->remote_consistent_lsn < min_feedback.remote_consistent_lsn)
 				min_feedback.remote_consistent_lsn = feedback->remote_consistent_lsn;
 		}
@@ -574,7 +551,6 @@ static void
 walprop_sigusr2(SIGNAL_ARGS)
 {
 	int			save_errno = errno;
-
 	got_SIGUSR2 = true;
 	SetLatch(MyLatch);
 	errno = save_errno;
@@ -622,7 +598,7 @@ walprop_pg_get_current_timestamp(WalProposer *wp)
 	return GetCurrentTimestamp();
 }

-TimeLineID
+static TimeLineID
 walprop_pg_get_timeline_id(void)
 {
 #if PG_VERSION_NUM >= 150000
@@ -641,20 +617,6 @@ walprop_pg_load_libpqwalreceiver(void)
 		wpg_log(ERROR, "libpqwalreceiver didn't initialize correctly");
 }

-static void
-walprop_pg_update_donor(WalProposer *wp, Safekeeper *donor, XLogRecPtr donor_lsn)
-{
-	WalproposerShmemState *wps = wp->api.get_shmem_state(wp);
-	char		donor_name[64];
-
-	pg_snprintf(donor_name, sizeof(donor_name), "%s:%s", donor->host, donor->port);
-	SpinLockAcquire(&wps->mutex);
-	memcpy(wps->donor_name, donor_name, sizeof(donor_name));
-	memcpy(wps->donor_conninfo, donor->conninfo, sizeof(donor->conninfo));
-	wps->donor_lsn = donor_lsn;
-	SpinLockRelease(&wps->mutex);
-}
-
 /* Helper function */
 static bool
 ensure_nonblocking_status(WalProposerConn *conn, bool is_nonblocking)
@@ -755,6 +717,7 @@ walprop_connect_start(Safekeeper *sk)
 {
 	Assert(sk->conn == NULL);
 	sk->conn = libpqwp_connect_start(sk->conninfo);
+
 }

 static WalProposerConnectPollStatusType
@@ -1128,7 +1091,7 @@ static void
 StartProposerReplication(WalProposer *wp, StartReplicationCmd *cmd)
 {
 	XLogRecPtr	FlushPtr;
-	__attribute__((unused)) TimeLineID currTLI;
+	 __attribute__((unused)) TimeLineID	currTLI;

 #if PG_VERSION_NUM < 150000
 	if (ThisTimeLineID == 0)
@@ -1332,13 +1295,116 @@ XLogBroadcastWalProposer(WalProposer *wp)
 	}
 }

-/*
-  Used to download WAL before basebackup for logical walsenders from sk, no longer
-  needed because walsender always uses neon_walreader.
- */
+/* Download WAL before basebackup for logical walsenders from sk, if needed */
 static bool
 WalProposerRecovery(WalProposer *wp, Safekeeper *sk)
 {
+	char	   *err;
+	WalReceiverConn *wrconn;
+	WalRcvStreamOptions options;
+	char		conninfo[MAXCONNINFO];
+	TimeLineID	timeline;
+	XLogRecPtr	startpos;
+	XLogRecPtr	endpos;
+
+	startpos = GetLogRepRestartLSN(wp);
+	if (startpos == InvalidXLogRecPtr)
+		return true;			/* recovery not needed */
+	endpos = wp->propEpochStartLsn;
+
+	timeline = wp->greetRequest.timeline;
+
+	if (!neon_auth_token)
+	{
+		memcpy(conninfo, sk->conninfo, MAXCONNINFO);
+	}
+	else
+	{
+		int			written = 0;
+
+		written = snprintf((char *) conninfo, MAXCONNINFO, "password=%s %s", neon_auth_token, sk->conninfo);
+		if (written > MAXCONNINFO || written < 0)
+			wpg_log(FATAL, "could not append password to the safekeeper connection string");
+	}
+
+#if PG_MAJORVERSION_NUM < 16
+	wrconn = walrcv_connect(conninfo, false, "wal_proposer_recovery", &err);
+#else
+	wrconn = walrcv_connect(conninfo, false, false, "wal_proposer_recovery", &err);
+#endif
+
+	if (!wrconn)
+	{
+		ereport(WARNING,
+				(errmsg("could not connect to WAL acceptor %s:%s: %s",
+						sk->host, sk->port,
+						err)));
+		return false;
+	}
+	wpg_log(LOG,
+			"start recovery for logical replication from %s:%s starting from %X/%08X till %X/%08X timeline "
+			"%d",
+			sk->host, sk->port, (uint32) (startpos >> 32),
+			(uint32) startpos, (uint32) (endpos >> 32), (uint32) endpos, timeline);
+
+	options.logical = false;
+	options.startpoint = startpos;
+	options.slotname = NULL;
+	options.proto.physical.startpointTLI = timeline;
+
+	if (walrcv_startstreaming(wrconn, &options))
+	{
+		XLogRecPtr	rec_start_lsn;
+		XLogRecPtr	rec_end_lsn = 0;
+		int			len;
+		char	   *buf;
+		pgsocket	wait_fd = PGINVALID_SOCKET;
+
+		while ((len = walrcv_receive(wrconn, &buf, &wait_fd)) >= 0)
+		{
+			if (len == 0)
+			{
+				(void) WaitLatchOrSocket(
+										 MyLatch, WL_EXIT_ON_PM_DEATH | WL_SOCKET_READABLE, wait_fd,
+										 -1, WAIT_EVENT_WAL_RECEIVER_MAIN);
+			}
+			else
+			{
+				Assert(buf[0] == 'w' || buf[0] == 'k');
+				if (buf[0] == 'k')
+					continue;	/* keepalive */
+				memcpy(&rec_start_lsn, &buf[XLOG_HDR_START_POS],
+					   sizeof rec_start_lsn);
+				rec_start_lsn = pg_ntoh64(rec_start_lsn);
+				rec_end_lsn = rec_start_lsn + len - XLOG_HDR_SIZE;
+
+				/* write WAL to disk */
+				XLogWalPropWrite(sk->wp, &buf[XLOG_HDR_SIZE], len - XLOG_HDR_SIZE, rec_start_lsn);
+
+				ereport(DEBUG1,
+						(errmsg("Recover message %X/%X length %d",
+								LSN_FORMAT_ARGS(rec_start_lsn), len)));
+				if (rec_end_lsn >= endpos)
+					break;
+			}
+		}
+		ereport(LOG,
+				(errmsg("end of replication stream at %X/%X: %m",
+						LSN_FORMAT_ARGS(rec_end_lsn))));
+		walrcv_disconnect(wrconn);
+
+		/* failed to receive all WAL till endpos */
+		if (rec_end_lsn < endpos)
+			return false;
+	}
+	else
+	{
+		ereport(LOG,
+				(errmsg("primary server contains no more WAL on requested timeline %u LSN %X/%08X",
+						timeline, (uint32) (startpos >> 32), (uint32) startpos)));
+		return false;
+	}
+
 	return true;
 }

@@ -1479,7 +1545,7 @@ walprop_pg_wal_reader_allocate(Safekeeper *sk)

 	snprintf(log_prefix, sizeof(log_prefix), WP_LOG_PREFIX "sk %s:%s nwr: ", sk->host, sk->port);
 	Assert(!sk->xlogreader);
-	sk->xlogreader = NeonWALReaderAllocate(wal_segment_size, sk->wp->propEpochStartLsn, log_prefix);
+	sk->xlogreader = NeonWALReaderAllocate(wal_segment_size, sk->wp->propEpochStartLsn, sk->wp, log_prefix);
 	if (sk->xlogreader == NULL)
 		wpg_log(FATAL, "failed to allocate xlog reader");
 }
@@ -1894,8 +1960,8 @@ CombineHotStanbyFeedbacks(HotStandbyFeedback *hs, WalProposer *wp)
 static void
 walprop_pg_process_safekeeper_feedback(WalProposer *wp, Safekeeper *sk)
 {
-	HotStandbyFeedback hsFeedback;
-	bool		needToAdvanceSlot = false;
+	HotStandbyFeedback	hsFeedback;
+	bool				needToAdvanceSlot = false;

 	if (wp->config->syncSafekeepers)
 		return;
@@ -2029,25 +2095,22 @@ GetLogRepRestartLSN(WalProposer *wp)
 	return lrRestartLsn;
 }

-void
-SetNeonCurrentClusterSize(uint64 size)
+void SetNeonCurrentClusterSize(uint64 size)
 {
 	pg_atomic_write_u64(&walprop_shared->currentClusterSize, size);
 }

-uint64
-GetNeonCurrentClusterSize(void)
+uint64 GetNeonCurrentClusterSize(void)
 {
 	return pg_atomic_read_u64(&walprop_shared->currentClusterSize);
 }
-uint64		GetNeonCurrentClusterSize(void);
+uint64 GetNeonCurrentClusterSize(void);


 static const walproposer_api walprop_pg = {
 	.get_shmem_state = walprop_pg_get_shmem_state,
 	.start_streaming = walprop_pg_start_streaming,
 	.get_flush_rec_ptr = walprop_pg_get_flush_rec_ptr,
-	.update_donor = walprop_pg_update_donor,
 	.get_current_timestamp = walprop_pg_get_current_timestamp,
 	.conn_error_message = walprop_error_message,
 	.conn_status = walprop_status,
--- a/pgxn/neon/walsender_hooks.c
+++ b/pgxn/neon/walsender_hooks.c
@@ -1,172 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * walsender_hooks.c
- *
- * Implements XLogReaderRoutine in terms of NeonWALReader. Allows for
- * fetching WAL from safekeepers, which normal xlogreader can't do.
- *
- *-------------------------------------------------------------------------
- */
-#include "walsender_hooks.h"
-#include "postgres.h"
-#include "fmgr.h"
-#include "access/xlogdefs.h"
-#include "replication/walsender.h"
-#include "access/xlog.h"
-#include "access/xlog_internal.h"
-#include "access/xlogreader.h"
-#include "miscadmin.h"
-#include "utils/wait_event.h"
-#include "utils/guc.h"
-#include "postmaster/interrupt.h"
-
-#include "neon_walreader.h"
-#include "walproposer.h"
-
-static NeonWALReader *wal_reader = NULL;
-extern XLogRecPtr WalSndWaitForWal(XLogRecPtr loc);
-extern bool GetDonorShmem(XLogRecPtr *donor_lsn);
-
-static XLogRecPtr
-NeonWALReadWaitForWAL(XLogRecPtr loc)
-{
-	while (!NeonWALReaderUpdateDonor(wal_reader))
-	{
-		pg_usleep(1000);
-		CHECK_FOR_INTERRUPTS();
-	}
-
-	return WalSndWaitForWal(loc);
-}
-
-static int
-NeonWALPageRead(
-				XLogReaderState *xlogreader,
-				XLogRecPtr targetPagePtr,
-				int reqLen,
-				XLogRecPtr targetRecPtr,
-				char *readBuf)
-{
-	XLogRecPtr	rem_lsn;
-
-	/* Wait for flush pointer to advance past our request */
-	XLogRecPtr	flushptr = NeonWALReadWaitForWAL(targetPagePtr + reqLen);
-	int			count;
-
-	if (flushptr < targetPagePtr + reqLen)
-		return -1;
-
-	/* Read at most XLOG_BLCKSZ bytes */
-	if (targetPagePtr + XLOG_BLCKSZ <= flushptr)
-		count = XLOG_BLCKSZ;
-	else
-		count = flushptr - targetPagePtr;
-
-	/*
-	 * Sometimes walsender requests non-monotonic sequences of WAL. If that's
-	 * the case, we have to reset streaming from remote at the correct
-	 * position. For example, walsender may try to verify the segment header
-	 * when trying to read in the middle of it.
-	 */
-	rem_lsn = NeonWALReaderGetRemLsn(wal_reader);
-	if (rem_lsn != InvalidXLogRecPtr && targetPagePtr != rem_lsn)
-	{
-		NeonWALReaderResetRemote(wal_reader);
-	}
-
-	for (;;)
-	{
-		NeonWALReadResult res = NeonWALRead(
-											wal_reader,
-											readBuf,
-											targetPagePtr,
-											count,
-											walprop_pg_get_timeline_id());
-
-		if (res == NEON_WALREAD_SUCCESS)
-		{
-			/*
-			 * Setting ws_tli is required by the XLogReaderRoutine, it is used
-			 * for segment name generation in error reports.
-			 *
-			 * ReadPageInternal updates ws_segno after calling cb on its own
-			 * and XLogReaderRoutine description doesn't require it, but
-			 * WALRead sets, let's follow it.
-			 */
-			xlogreader->seg.ws_tli = NeonWALReaderGetSegment(wal_reader)->ws_tli;
-			xlogreader->seg.ws_segno = NeonWALReaderGetSegment(wal_reader)->ws_segno;
-
-			/*
-			 * ws_file doesn't exist in case of remote read, and isn't used by
-			 * xlogreader except by WALRead on which we don't rely anyway.
-			 */
-			return count;
-		}
-		if (res == NEON_WALREAD_ERROR)
-		{
-			elog(ERROR, "[walsender] Failed to read WAL (req_lsn=%X/%X, len=%d): %s",
-				 LSN_FORMAT_ARGS(targetPagePtr),
-				 reqLen,
-				 NeonWALReaderErrMsg(wal_reader));
-			return -1;
-		}
-
-		/*
-		 * Res is WOULDBLOCK, so we wait on the socket, recreating event set
-		 * if necessary
-		 */
-		{
-
-			pgsocket	sock = NeonWALReaderSocket(wal_reader);
-			uint32_t	reader_events = NeonWALReaderEvents(wal_reader);
-			long		timeout_ms = 1000;
-
-			ResetLatch(MyLatch);
-			CHECK_FOR_INTERRUPTS();
-			if (ConfigReloadPending)
-			{
-				ConfigReloadPending = false;
-				ProcessConfigFile(PGC_SIGHUP);
-			}
-
-			WaitLatchOrSocket(
-							  MyLatch,
-							  WL_LATCH_SET | WL_EXIT_ON_PM_DEATH | reader_events,
-							  sock,
-							  timeout_ms,
-							  WAIT_EVENT_WAL_SENDER_MAIN);
-		}
-	}
-}
-
-static void
-NeonWALReadSegmentOpen(XLogReaderState *xlogreader, XLogSegNo nextSegNo, TimeLineID *tli_p)
-{
-	neon_wal_segment_open(wal_reader, nextSegNo, tli_p);
-	xlogreader->seg.ws_file = NeonWALReaderGetSegment(wal_reader)->ws_file;
-}
-
-static void
-NeonWALReadSegmentClose(XLogReaderState *xlogreader)
-{
-	neon_wal_segment_close(wal_reader);
-	xlogreader->seg.ws_file = NeonWALReaderGetSegment(wal_reader)->ws_file;
-}
-
-void
-NeonOnDemandXLogReaderRoutines(XLogReaderRoutine *xlr)
-{
-	if (!wal_reader)
-	{
-		XLogRecPtr	epochStartLsn = pg_atomic_read_u64(&GetWalpropShmemState()->propEpochStartLsn);
-
-		if (epochStartLsn == 0)
-		{
-			elog(ERROR, "Unable to start walsender when propEpochStartLsn is 0!");
-		}
-		wal_reader = NeonWALReaderAllocate(wal_segment_size, epochStartLsn, "[walsender] ");
-	}
-	xlr->page_read = NeonWALPageRead;
-	xlr->segment_open = NeonWALReadSegmentOpen;
-	xlr->segment_close = NeonWALReadSegmentClose;
-}
--- a/pgxn/neon/walsender_hooks.h
+++ b/pgxn/neon/walsender_hooks.h
@@ -1,7 +0,0 @@
-#ifndef __WALSENDER_HOOKS_H__
-#define __WALSENDER_HOOKS_H__
-
-struct XLogReaderRoutine;
-void		NeonOnDemandXLogReaderRoutines(struct XLogReaderRoutine *xlr);
-
-#endif
--- a/pgxn/neon_test_utils/Makefile
+++ b/pgxn/neon_test_utils/Makefile
@@ -7,7 +7,7 @@ OBJS = \
 	neontest.o

 EXTENSION = neon_test_utils
-DATA = neon_test_utils--1.1.sql
+DATA = neon_test_utils--1.0.sql
 PGFILEDESC = "neon_test_utils - helpers for neon testing and debugging"

 PG_CONFIG = pg_config
--- a/pgxn/neon_test_utils/neon_test_utils--1.0.sql
+++ b/pgxn/neon_test_utils/neon_test_utils--1.0.sql
@@ -31,12 +31,12 @@ AS 'MODULE_PATHNAME', 'clear_buffer_cache'
 LANGUAGE C STRICT
 PARALLEL UNSAFE;

-CREATE FUNCTION get_raw_page_at_lsn(relname text, forkname text, blocknum int8, request_lsn pg_lsn, not_modified_since pg_lsn)
+CREATE FUNCTION get_raw_page_at_lsn(relname text, forkname text, blocknum int8, lsn pg_lsn)
 RETURNS bytea
 AS 'MODULE_PATHNAME', 'get_raw_page_at_lsn'
 LANGUAGE C PARALLEL UNSAFE;

-CREATE FUNCTION get_raw_page_at_lsn(tbspc oid, db oid, relfilenode oid, forknum int8, blocknum int8, request_lsn pg_lsn, not_modified_since pg_lsn)
+CREATE FUNCTION get_raw_page_at_lsn(tbspc oid, db oid, relfilenode oid, forknum int8, blocknum int8, lsn pg_lsn)
 RETURNS bytea
 AS 'MODULE_PATHNAME', 'get_raw_page_at_lsn_ex'
 LANGUAGE C PARALLEL UNSAFE;
--- a/pgxn/neon_test_utils/neon_test_utils.control
+++ b/pgxn/neon_test_utils/neon_test_utils.control
@@ -1,6 +1,6 @@
 # neon_test_utils extension
 comment = 'helpers for neon testing and debugging'
-default_version = '1.1'
+default_version = '1.0'
 module_pathname = '$libdir/neon_test_utils'
 relocatable = true
 trusted = true
--- a/pgxn/neon_test_utils/neontest.c
+++ b/pgxn/neon_test_utils/neontest.c
@@ -48,10 +48,10 @@ PG_FUNCTION_INFO_V1(neon_xlogflush);
 */
 #if PG_MAJORVERSION_NUM < 16
 typedef void (*neon_read_at_lsn_type) (NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-									   XLogRecPtr request_lsn, XLogRecPtr not_modified_since, char *buffer);
+									   XLogRecPtr request_lsn, bool request_latest, char *buffer);
 #else
 typedef void (*neon_read_at_lsn_type) (NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-									   XLogRecPtr request_lsn, XLogRecPtr not_modified_since, void *buffer);
+									   XLogRecPtr request_lsn, bool request_latest, void *buffer);
 #endif

 static neon_read_at_lsn_type neon_read_at_lsn_ptr;
@@ -299,11 +299,8 @@ get_raw_page_at_lsn(PG_FUNCTION_ARGS)
 	text	   *forkname;
 	uint32		blkno;

-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
-
-	if (PG_NARGS() != 5)
-		elog(ERROR, "unexpected number of arguments in SQL function signature");
+	bool		request_latest = PG_ARGISNULL(3);
+	uint64		read_lsn = request_latest ? GetXLogInsertRecPtr() : PG_GETARG_INT64(3);

 	if (PG_ARGISNULL(0) || PG_ARGISNULL(1) || PG_ARGISNULL(2))
 		PG_RETURN_NULL();
@@ -312,9 +309,6 @@ get_raw_page_at_lsn(PG_FUNCTION_ARGS)
 	forkname = PG_GETARG_TEXT_PP(1);
 	blkno = PG_GETARG_UINT32(2);

-	request_lsn = PG_ARGISNULL(3) ? GetXLogInsertRecPtr() : PG_GETARG_LSN(3);
-	not_modified_since = PG_ARGISNULL(4) ? request_lsn : PG_GETARG_LSN(4);
-
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
@@ -367,7 +361,7 @@ get_raw_page_at_lsn(PG_FUNCTION_ARGS)
 	SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
 	raw_page_data = VARDATA(raw_page);

-	neon_read_at_lsn(InfoFromRelation(rel), forknum, blkno, request_lsn, not_modified_since, raw_page_data);
+	neon_read_at_lsn(InfoFromRelation(rel), forknum, blkno, read_lsn, request_latest, raw_page_data);

 	relation_close(rel, AccessShareLock);

@@ -386,9 +380,6 @@ get_raw_page_at_lsn_ex(PG_FUNCTION_ARGS)
 {
 	char	   *raw_page_data;

-	if (PG_NARGS() != 7)
-		elog(ERROR, "unexpected number of arguments in SQL function signature");
-
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
@@ -412,20 +403,18 @@ get_raw_page_at_lsn_ex(PG_FUNCTION_ARGS)
 		};

 		ForkNumber	forknum = PG_GETARG_UINT32(3);
+
 		uint32		blkno = PG_GETARG_UINT32(4);
-		XLogRecPtr	request_lsn;
-		XLogRecPtr	not_modified_since;
+		bool		request_latest = PG_ARGISNULL(5);
+		uint64		read_lsn = request_latest ? GetXLogInsertRecPtr() : PG_GETARG_INT64(5);

 		/* Initialize buffer to copy to */
 		bytea	   *raw_page = (bytea *) palloc(BLCKSZ + VARHDRSZ);

-		request_lsn = PG_ARGISNULL(5) ? GetXLogInsertRecPtr() : PG_GETARG_LSN(5);
-		not_modified_since = PG_ARGISNULL(6) ? request_lsn : PG_GETARG_LSN(6);
-
 		SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
 		raw_page_data = VARDATA(raw_page);

-		neon_read_at_lsn(rinfo, forknum, blkno, request_lsn, not_modified_since, raw_page_data);
+		neon_read_at_lsn(rinfo, forknum, blkno, read_lsn, request_latest, raw_page_data);
 		PG_RETURN_BYTEA_P(raw_page);
 	}
 }
--- a/proxy/Cargo.toml
+++ b/proxy/Cargo.toml
@@ -9,8 +9,6 @@ default = []
 testing = []

 [dependencies]
-workspace_hack.workspace = true
-
 anyhow.workspace = true
 async-compression.workspace = true
 async-trait.workspace = true
@@ -48,7 +46,6 @@ lasso = { workspace = true, features = ["multi-threaded"] }
 md5.workspace = true
 measured = { workspace = true, features = ["lasso"] }
 metrics.workspace = true
-moka = { version = "0.12.7", features = ["future"] }
 once_cell.workspace = true
 opentelemetry.workspace = true
 parking_lot.workspace = true
@@ -62,8 +59,8 @@ prometheus.workspace = true
 rand.workspace = true
 regex.workspace = true
 remote_storage = { version = "0.1", path = "../libs/remote_storage/" }
-reqwest.workspace = true
-reqwest-middleware = { workspace = true, features = ["json"] }
+reqwest = { workspace = true, features = ["json"] }
+reqwest-middleware.workspace = true
 reqwest-retry.workspace = true
 reqwest-tracing.workspace = true
 routerify.workspace = true
@@ -87,7 +84,6 @@ tokio-postgres.workspace = true
 tokio-rustls.workspace = true
 tokio-util.workspace = true
 tokio = { workspace = true, features = ["signal"] }
-tower-service.workspace = true
 tracing-opentelemetry.workspace = true
 tracing-subscriber.workspace = true
 tracing-utils.workspace = true
@@ -103,6 +99,8 @@ postgres-native-tls.workspace = true
 postgres-protocol.workspace = true
 redis.workspace = true

+workspace_hack.workspace = true
+
 [dev-dependencies]
 camino-tempfile.workspace = true
 fallible-iterator.workspace = true
--- a/proxy/src/auth/backend.rs
+++ b/proxy/src/auth/backend.rs
@@ -69,10 +69,8 @@ pub enum BackendType<'a, T, D> {
    Link(MaybeOwned<'a, url::ApiUrl>, D),
 }

-#[cfg(test)]
-#[async_trait::async_trait]
 pub trait TestBackend: Send + Sync + 'static {
-    async fn wake_compute(&self) -> Result<CachedNodeInfo, console::errors::WakeComputeError>;
+    fn wake_compute(&self) -> Result<CachedNodeInfo, console::errors::WakeComputeError>;
    fn get_allowed_ips_and_secret(
        &self,
    ) -> Result<(CachedAllowedIps, Option<CachedRoleSecret>), console::errors::GetAuthInfoError>;
@@ -155,13 +153,7 @@ pub struct ComputeUserInfo {

 impl ComputeUserInfo {
    pub fn endpoint_cache_key(&self) -> EndpointCacheKey {
-        let id = EndpointIdInt::from(&self.endpoint);
-        let key = EndpointCacheKey::from(id);
-        if self.options.is_empty() {
-            key
-        } else {
-            key.with_options(self.options.to_string())
-        }
+        self.options.get_cache_key(&self.endpoint)
    }
 }

@@ -351,7 +343,7 @@ async fn auth_quirks(
        Err(e) => {
            if e.is_auth_failed() {
                // The password could have been changed, so we invalidate the cache.
-                cached_entry.invalidate().await;
+                cached_entry.invalidate();
            }
            Err(e)
        }
--- a/proxy/src/auth/credentials.rs
+++ b/proxy/src/auth/credentials.rs
@@ -292,7 +292,7 @@ mod tests {
            ComputeUserInfoMaybeEndpoint::parse(&mut ctx, &options, sni, common_names.as_ref())?;
        assert_eq!(user_info.user, "john_doe");
        assert_eq!(user_info.endpoint_id.as_deref(), Some("foo"));
-        assert_eq!(user_info.options.to_string(), "");
+        assert_eq!(user_info.options.get_cache_key("foo"), "foo");

        Ok(())
    }
@@ -451,8 +451,8 @@ mod tests {
            ComputeUserInfoMaybeEndpoint::parse(&mut ctx, &options, sni, common_names.as_ref())?;
        assert_eq!(user_info.endpoint_id.as_deref(), Some("project"));
        assert_eq!(
-            user_info.options.to_string(),
-            "endpoint_type:read_write lsn:0/2"
+            user_info.options.get_cache_key("project"),
+            "project endpoint_type:read_write lsn:0/2"
        );

        Ok(())
--- a/proxy/src/bin/pg_sni_router.rs
+++ b/proxy/src/bin/pg_sni_router.rs
@@ -279,7 +279,7 @@ async fn handle_client(

    // doesn't yet matter as pg-sni-router doesn't report analytics logs
    ctx.set_success();
-    ctx.log_connect();
+    ctx.log();

    // Starting from here we only proxy the client's traffic.
    info!("performing the proxy pass...");
--- a/proxy/src/bin/proxy.rs
+++ b/proxy/src/bin/proxy.rs
@@ -118,11 +118,8 @@ struct ProxyCliArgs {
    #[clap(long, default_value = config::CacheOptions::CACHE_DEFAULT_OPTIONS)]
    wake_compute_cache: String,
    /// lock for `wake_compute` api method. example: "shards=32,permits=4,epoch=10m,timeout=1s". (use `permits=0` to disable).
-    #[clap(long, default_value = config::ConcurrencyLockOptions::DEFAULT_OPTIONS_WAKE_COMPUTE_LOCK)]
+    #[clap(long, default_value = config::WakeComputeLockOptions::DEFAULT_OPTIONS_WAKE_COMPUTE_LOCK)]
    wake_compute_lock: String,
-    /// lock for `connect_compute` api method. example: "shards=32,permits=4,epoch=10m,timeout=1s". (use `permits=0` to disable).
-    #[clap(long, default_value = config::ConcurrencyLockOptions::DEFAULT_OPTIONS_CONNECT_COMPUTE_LOCK)]
-    connect_compute_lock: String,
    /// Allow self-signed certificates for compute nodes (for testing)
    #[clap(long, default_value_t = false, value_parser = clap::builder::BoolishValueParser::new(), action = clap::ArgAction::Set)]
    allow_self_signed_compute: bool,
@@ -532,21 +529,24 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
                endpoint_cache_config,
            )));

-            let config::ConcurrencyLockOptions {
+            let config::WakeComputeLockOptions {
                shards,
                permits,
                epoch,
                timeout,
            } = args.wake_compute_lock.parse()?;
            info!(permits, shards, ?epoch, "Using NodeLocks (wake_compute)");
-            let locks = Box::leak(Box::new(console::locks::ApiLocks::new(
-                "wake_compute_lock",
-                permits,
-                shards,
-                timeout,
-                epoch,
-                &Metrics::get().wake_compute_lock,
-            )?));
+            let locks = Box::leak(Box::new(
+                console::locks::ApiLocks::new(
+                    "wake_compute_lock",
+                    permits,
+                    shards,
+                    timeout,
+                    epoch,
+                    &Metrics::get().wake_compute_lock,
+                )
+                .unwrap(),
+            ));
            tokio::spawn(locks.garbage_collect_worker());

            let url = args.auth_endpoint.parse()?;
@@ -572,23 +572,6 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
            auth::BackendType::Link(MaybeOwned::Owned(url), ())
        }
    };
-
-    let config::ConcurrencyLockOptions {
-        shards,
-        permits,
-        epoch,
-        timeout,
-    } = args.connect_compute_lock.parse()?;
-    info!(permits, shards, ?epoch, "Using NodeLocks (connect_compute)");
-    let connect_compute_locks = console::locks::ApiLocks::new(
-        "connect_compute_lock",
-        permits,
-        shards,
-        timeout,
-        epoch,
-        &Metrics::get().proxy.connect_compute_lock,
-    )?;
-
    let http_config = HttpConfig {
        request_timeout: args.sql_over_http.sql_over_http_timeout,
        pool_options: GlobalConnPoolOptions {
@@ -624,14 +607,11 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
        region: args.region.clone(),
        aws_region: args.aws_region.clone(),
        wake_compute_retry_config: config::RetryConfig::parse(&args.wake_compute_retry)?,
-        connect_compute_locks,
        connect_to_compute_retry_config: config::RetryConfig::parse(
            &args.connect_to_compute_retry,
        )?,
    }));

-    tokio::spawn(config.connect_compute_locks.garbage_collect_worker());
-
    Ok(config)
 }

--- a/proxy/src/cache.rs
+++ b/proxy/src/cache.rs
@@ -1,5 +1,7 @@
 pub mod common;
 pub mod endpoints;
 pub mod project_info;
+mod timed_lru;

 pub use common::{Cache, Cached};
+pub use timed_lru::TimedLru;
--- a/proxy/src/cache/common.rs
+++ b/proxy/src/cache/common.rs
@@ -3,28 +3,35 @@ use std::ops::{Deref, DerefMut};
 /// A generic trait which exposes types of cache's key and value,
 /// as well as the notion of cache entry invalidation.
 /// This is useful for [`Cached`].
-#[allow(async_fn_in_trait)]
 pub trait Cache {
+    /// Entry's key.
+    type Key;
+
+    /// Entry's value.
+    type Value;
+
    /// Used for entry invalidation.
-    type LookupInfo;
+    type LookupInfo<Key>;

    /// Invalidate an entry using a lookup info.
    /// We don't have an empty default impl because it's error-prone.
-    async fn invalidate(&self, _: &Self::LookupInfo);
+    fn invalidate(&self, _: &Self::LookupInfo<Self::Key>);
 }

 impl<C: Cache> Cache for &C {
-    type LookupInfo = C::LookupInfo;
+    type Key = C::Key;
+    type Value = C::Value;
+    type LookupInfo<Key> = C::LookupInfo<Key>;

-    async fn invalidate(&self, info: &Self::LookupInfo) {
-        C::invalidate(self, info).await
+    fn invalidate(&self, info: &Self::LookupInfo<Self::Key>) {
+        C::invalidate(self, info)
    }
 }

 /// Wrapper for convenient entry invalidation.
-pub struct Cached<C: Cache, V> {
+pub struct Cached<C: Cache, V = <C as Cache>::Value> {
    /// Cache + lookup info.
-    pub token: Option<(C, C::LookupInfo)>,
+    pub token: Option<(C, C::LookupInfo<C::Key>)>,

    /// The value itself.
    pub value: V,
@@ -47,9 +54,9 @@ impl<C: Cache, V> Cached<C, V> {
    }

    /// Drop this entry from a cache if it's still there.
-    pub async fn invalidate(self) -> V {
+    pub fn invalidate(self) -> V {
        if let Some((cache, info)) = &self.token {
-            cache.invalidate(info).await;
+            cache.invalidate(info);
        }
        self.value
    }
@@ -73,16 +80,3 @@ impl<C: Cache, V> DerefMut for Cached<C, V> {
        &mut self.value
    }
 }
-
-impl<K, V, S> Cache for moka::future::Cache<K, V, S>
-where
-    K: std::hash::Hash + Eq + Send + Sync + 'static,
-    V: Clone + Send + Sync + 'static,
-    S: std::hash::BuildHasher + Clone + Send + Sync + 'static,
-{
-    type LookupInfo = K;
-
-    async fn invalidate(&self, key: &Self::LookupInfo) {
-        moka::future::Cache::invalidate(self, key).await
-    }
-}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
John Spray	9c097aa75f	Revised fragmentation logic	2024-04-25 18:15:26 +01:00
John Spray	1330a60d27	pull key diff into helper	2024-04-25 18:05:59 +01:00
John Spray	5c1135afcd	tests: add test_sharding_compaction	2024-04-25 18:05:59 +01:00
John Spray	4316f0fab2	Tidy up old size code	2024-04-25 18:05:59 +01:00
John Spray	987bfa23e1	pageserver: use shard-aware partitioning in tiered compaction	2024-04-25 18:04:23 +01:00
John Spray	43ec37adf6	pageserver: shard-aware keyspace partitioning	2024-04-25 18:04:23 +01:00