From decd265c99a160d5d5c37332ef23c2c0898b40f9 Mon Sep 17 00:00:00 2001
From: Tristan Partin <tristan@neon.tech>
Date: Tue, 11 Mar 2025 17:18:09 -0500
Subject: [PATCH] Revert notify to 6.0.0 (#11162)

The upgrade to 8.0.0 caused severe performance regressions in the
start_postgres_ms metric, which measures the time it takes from execing
Postgres to the time Postgres marks itself as ready in the
postmaster.pid file. We use the notify crate to watch for changes in the
pgdata directory and the postmaster.pid file.

Signed-off-by: Tristan Partin <tristan@neon.tech>
---
 Cargo.lock                | 42 +++++++++++++++++++++------------------
 Cargo.toml                |  4 +++-
 workspace_hack/Cargo.toml |  6 ++----
 3 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 778ff19fec..d023d340d4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3254,11 +3254,11 @@ dependencies = [
 
 [[package]]
 name = "inotify"
-version = "0.11.0"
+version = "0.9.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f37dccff2791ab604f9babef0ba14fbe0be30bd368dc541e2b08d07c8aa908f3"
+checksum = "f8069d3ec154eb856955c1c0fbffefbf5f3c40a104ec912d4797314c1801abff"
 dependencies = [
- "bitflags 2.8.0",
+ "bitflags 1.3.2",
  "inotify-sys",
  "libc",
 ]
@@ -3732,6 +3732,18 @@ dependencies = [
  "adler2",
 ]
 
+[[package]]
+name = "mio"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
+dependencies = [
+ "libc",
+ "log",
+ "wasi 0.11.0+wasi-snapshot-preview1",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "mio"
 version = "1.0.3"
@@ -3739,7 +3751,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2886843bf800fba2e3377cff24abf6379b4c4d5c6681eaf9ea5b0d15090450bd"
 dependencies = [
  "libc",
- "log",
  "wasi 0.11.0+wasi-snapshot-preview1",
  "windows-sys 0.52.0",
 ]
@@ -3817,29 +3828,23 @@ checksum = "38bf9645c8b145698bb0b18a4637dcacbc421ea49bef2317e4fd8065a387cf21"
 
 [[package]]
 name = "notify"
-version = "8.0.0"
+version = "6.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fee8403b3d66ac7b26aee6e40a897d85dc5ce26f44da36b8b73e987cc52e943"
+checksum = "6205bd8bb1e454ad2e27422015fb5e4f2bcc7e08fa8f27058670d208324a4d2d"
 dependencies = [
  "bitflags 2.8.0",
+ "crossbeam-channel",
  "filetime",
  "fsevent-sys",
  "inotify",
  "kqueue",
  "libc",
  "log",
- "mio",
- "notify-types",
+ "mio 0.8.11",
  "walkdir",
- "windows-sys 0.59.0",
+ "windows-sys 0.48.0",
 ]
 
-[[package]]
-name = "notify-types"
-version = "2.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e0826a989adedc2a244799e823aece04662b66609d96af8dff7ac6df9a8925d"
-
 [[package]]
 name = "ntapi"
 version = "0.4.1"
@@ -4980,7 +4985,7 @@ checksum = "22505a5c94da8e3b7c2996394d1c933236c4d743e81a410bcca4e6989fc066a4"
 dependencies = [
  "bytes",
  "heck",
- "itertools 0.10.5",
+ "itertools 0.12.1",
  "log",
  "multimap",
  "once_cell",
@@ -5021,7 +5026,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "81bddcdb20abf9501610992b6759a4c888aef7d1a7247ef75e2404275ac24af1"
 dependencies = [
  "anyhow",
- "itertools 0.10.5",
+ "itertools 0.12.1",
  "proc-macro2",
  "quote",
  "syn 2.0.90",
@@ -7123,7 +7128,7 @@ dependencies = [
  "backtrace",
  "bytes",
  "libc",
- "mio",
+ "mio 1.0.3",
  "parking_lot 0.12.1",
  "pin-project-lite",
  "signal-hook-registry",
@@ -8387,7 +8392,6 @@ dependencies = [
  "hyper-util",
  "indexmap 1.9.3",
  "indexmap 2.0.1",
- "itertools 0.10.5",
  "itertools 0.12.1",
  "lazy_static",
  "libc",
diff --git a/Cargo.toml b/Cargo.toml
index c59c4c5435..4a32b6d95d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -126,7 +126,9 @@ measured = { version = "0.0.22", features=["lasso"] }
 measured-process = { version = "0.0.22" }
 memoffset = "0.9"
 nix = { version = "0.27", features = ["dir", "fs", "process", "socket", "signal", "poll"] }
-notify = "8.0.0"
+# Do not update to >= 7.0.0, at least. The update will have a significant impact
+# on compute startup metrics (start_postgres_ms), >= 25% degradation.
+notify = "6.0.0"
 num_cpus = "1.15"
 num-traits = "0.2.15"
 once_cell = "1.13"
diff --git a/workspace_hack/Cargo.toml b/workspace_hack/Cargo.toml
index 4a6ab6e745..183cc66ab9 100644
--- a/workspace_hack/Cargo.toml
+++ b/workspace_hack/Cargo.toml
@@ -47,8 +47,7 @@ hyper-dff4ba8e3ae991db = { package = "hyper", version = "1", features = ["full"]
 hyper-util = { version = "0.1", features = ["client-legacy", "http1", "http2", "server", "service"] }
 indexmap-dff4ba8e3ae991db = { package = "indexmap", version = "1", default-features = false, features = ["std"] }
 indexmap-f595c2ba2a3f28df = { package = "indexmap", version = "2", features = ["serde"] }
-itertools-5ef9efb8ec2df382 = { package = "itertools", version = "0.12" }
-itertools-93f6ce9d446188ac = { package = "itertools", version = "0.10" }
+itertools = { version = "0.12" }
 lazy_static = { version = "1", default-features = false, features = ["spin_no_std"] }
 libc = { version = "0.2", features = ["extra_traits", "use_std"] }
 log = { version = "0.4", default-features = false, features = ["std"] }
@@ -115,8 +114,7 @@ half = { version = "2", default-features = false, features = ["num-traits"] }
 hashbrown = { version = "0.14", features = ["raw"] }
 indexmap-dff4ba8e3ae991db = { package = "indexmap", version = "1", default-features = false, features = ["std"] }
 indexmap-f595c2ba2a3f28df = { package = "indexmap", version = "2", features = ["serde"] }
-itertools-5ef9efb8ec2df382 = { package = "itertools", version = "0.12" }
-itertools-93f6ce9d446188ac = { package = "itertools", version = "0.10" }
+itertools = { version = "0.12" }
 libc = { version = "0.2", features = ["extra_traits", "use_std"] }
 log = { version = "0.4", default-features = false, features = ["std"] }
 memchr = { version = "2" }