only for console

## Summary of changes

saw some low-hanging codecov improvements. even if code coverage is
somewhat of a pointless game, might as well add tests where we can and
delete code if it's unused

Cargo.lock

@@ -3103,6 +3103,7 @@ dependencies = [
  "humantime-serde",
  "hyper",
  "itertools",
+ "md5",
  "metrics",
  "nix 0.26.2",
  "num-traits",
@@ -5764,6 +5765,7 @@ dependencies = [
  "serde",
  "serde_assert",
  "serde_json",
+ "serde_path_to_error",
  "serde_with",
  "signal-hook",
  "strum",

control_plane/src/pageserver.rs

@@ -407,6 +407,7 @@ impl PageServerNode {
                 .map(|x| x.parse::<bool>())
                 .transpose()
                 .context("Failed to parse 'gc_feedback' as bool")?,
+            heatmap_period: settings.remove("heatmap_period").map(|x| x.to_string()),
         };
 
         let request = models::TenantCreateRequest {
@@ -504,6 +505,7 @@ impl PageServerNode {
                     .map(|x| x.parse::<bool>())
                     .transpose()
                     .context("Failed to parse 'gc_feedback' as bool")?,
+                heatmap_period: settings.remove("heatmap_period").map(|x| x.to_string()),
             }
         };
 

libs/metrics/src/lib.rs

@@ -3,8 +3,11 @@
 //! Otherwise, we might not see all metrics registered via
 //! a default registry.
 #![deny(clippy::undocumented_unsafe_blocks)]
+
 use once_cell::sync::Lazy;
-use prometheus::core::{AtomicU64, Collector, GenericGauge, GenericGaugeVec};
+use prometheus::core::{
+    Atomic, AtomicU64, Collector, GenericCounter, GenericCounterVec, GenericGauge, GenericGaugeVec,
+};
 pub use prometheus::opts;
 pub use prometheus::register;
 pub use prometheus::Error;
@@ -132,3 +135,137 @@ fn get_rusage_stats() -> libc::rusage {
         rusage.assume_init()
     }
 }
+
+/// Create an [`IntCounterPairVec`] and registers to default registry.
+#[macro_export(local_inner_macros)]
+macro_rules! register_int_counter_pair_vec {
+    ($NAME1:expr, $HELP1:expr, $NAME2:expr, $HELP2:expr, $LABELS_NAMES:expr $(,)?) => {{
+        match (
+            $crate::register_int_counter_vec!($NAME1, $HELP1, $LABELS_NAMES),
+            $crate::register_int_counter_vec!($NAME2, $HELP2, $LABELS_NAMES),
+        ) {
+            (Ok(inc), Ok(dec)) => Ok($crate::IntCounterPairVec::new(inc, dec)),
+            (Err(e), _) | (_, Err(e)) => Err(e),
+        }
+    }};
+}
+/// Create an [`IntCounterPair`] and registers to default registry.
+#[macro_export(local_inner_macros)]
+macro_rules! register_int_counter_pair {
+    ($NAME1:expr, $HELP1:expr, $NAME2:expr, $HELP2:expr $(,)?) => {{
+        match (
+            $crate::register_int_counter!($NAME1, $HELP1),
+            $crate::register_int_counter!($NAME2, $HELP2),
+        ) {
+            (Ok(inc), Ok(dec)) => Ok($crate::IntCounterPair::new(inc, dec)),
+            (Err(e), _) | (_, Err(e)) => Err(e),
+        }
+    }};
+}
+
+/// A Pair of [`GenericCounterVec`]s. Like an [`GenericGaugeVec`] but will always observe changes
+pub struct GenericCounterPairVec<P: Atomic> {
+    inc: GenericCounterVec<P>,
+    dec: GenericCounterVec<P>,
+}
+
+/// A Pair of [`GenericCounter`]s. Like an [`GenericGauge`] but will always observe changes
+pub struct GenericCounterPair<P: Atomic> {
+    inc: GenericCounter<P>,
+    dec: GenericCounter<P>,
+}
+
+impl<P: Atomic> GenericCounterPairVec<P> {
+    pub fn new(inc: GenericCounterVec<P>, dec: GenericCounterVec<P>) -> Self {
+        Self { inc, dec }
+    }
+
+    /// `get_metric_with_label_values` returns the [`GenericCounterPair<P>`] for the given slice
+    /// of label values (same order as the VariableLabels in Desc). If that combination of
+    /// label values is accessed for the first time, a new [`GenericCounterPair<P>`] is created.
+    ///
+    /// An error is returned if the number of label values is not the same as the
+    /// number of VariableLabels in Desc.
+    pub fn get_metric_with_label_values(&self, vals: &[&str]) -> Result<GenericCounterPair<P>> {
+        Ok(GenericCounterPair {
+            inc: self.inc.get_metric_with_label_values(vals)?,
+            dec: self.dec.get_metric_with_label_values(vals)?,
+        })
+    }
+
+    /// `with_label_values` works as `get_metric_with_label_values`, but panics if an error
+    /// occurs.
+    pub fn with_label_values(&self, vals: &[&str]) -> GenericCounterPair<P> {
+        self.get_metric_with_label_values(vals).unwrap()
+    }
+}
+
+impl<P: Atomic> GenericCounterPair<P> {
+    pub fn new(inc: GenericCounter<P>, dec: GenericCounter<P>) -> Self {
+        Self { inc, dec }
+    }
+
+    /// Increment the gauge by 1, returning a guard that decrements by 1 on drop.
+    pub fn guard(&self) -> GenericCounterPairGuard<P> {
+        self.inc.inc();
+        GenericCounterPairGuard(self.dec.clone())
+    }
+
+    /// Increment the gauge by n, returning a guard that decrements by n on drop.
+    pub fn guard_by(&self, n: P::T) -> GenericCounterPairGuardBy<P> {
+        self.inc.inc_by(n);
+        GenericCounterPairGuardBy(self.dec.clone(), n)
+    }
+
+    /// Increase the gauge by 1.
+    #[inline]
+    pub fn inc(&self) {
+        self.inc.inc();
+    }
+
+    /// Decrease the gauge by 1.
+    #[inline]
+    pub fn dec(&self) {
+        self.dec.inc();
+    }
+
+    /// Add the given value to the gauge. (The value can be
+    /// negative, resulting in a decrement of the gauge.)
+    #[inline]
+    pub fn inc_by(&self, v: P::T) {
+        self.inc.inc_by(v);
+    }
+
+    /// Subtract the given value from the gauge. (The value can be
+    /// negative, resulting in an increment of the gauge.)
+    #[inline]
+    pub fn dec_by(&self, v: P::T) {
+        self.dec.inc_by(v);
+    }
+}
+
+/// Guard returned by [`GenericCounterPair::guard`]
+pub struct GenericCounterPairGuard<P: Atomic>(GenericCounter<P>);
+
+impl<P: Atomic> Drop for GenericCounterPairGuard<P> {
+    fn drop(&mut self) {
+        self.0.inc();
+    }
+}
+/// Guard returned by [`GenericCounterPair::guard_by`]
+pub struct GenericCounterPairGuardBy<P: Atomic>(GenericCounter<P>, P::T);
+
+impl<P: Atomic> Drop for GenericCounterPairGuardBy<P> {
+    fn drop(&mut self) {
+        self.0.inc_by(self.1);
+    }
+}
+
+/// A Pair of [`IntCounterVec`]s. Like an [`IntGaugeVec`] but will always observe changes
+pub type IntCounterPairVec = GenericCounterPairVec<AtomicU64>;
+
+/// A Pair of [`IntCounter`]s. Like an [`IntGauge`] but will always observe changes
+pub type IntCounterPair = GenericCounterPair<AtomicU64>;
+
+/// A guard for [`IntCounterPair`] that will decrement the gauge on drop
+pub type IntCounterPairGuard = GenericCounterPairGuard<AtomicU64>;

libs/pageserver_api/src/models.rs

@@ -237,6 +237,7 @@ pub struct TenantConfig {
     pub min_resident_size_override: Option<u64>,
     pub evictions_low_residence_duration_metric_threshold: Option<String>,
     pub gc_feedback: Option<bool>,
+    pub heatmap_period: Option<String>,
 }
 
 /// A flattened analog of a `pagesever::tenant::LocationMode`, which

libs/utils/Cargo.toml

@@ -50,6 +50,8 @@ const_format.workspace = true
 # why is it only here? no other crate should use it, streams are rarely needed.
 tokio-stream = { version = "0.1.14" }
 
+serde_path_to_error.workspace = true
+
 [dev-dependencies]
 byteorder.workspace = true
 bytes.workspace = true

libs/utils/src/http/json.rs

@@ -25,8 +25,12 @@ pub async fn json_request_or_empty_body<T: for<'de> Deserialize<'de>>(
     if body.remaining() == 0 {
         return Ok(None);
     }
-    serde_json::from_reader(body.reader())
-        .context("Failed to parse json request")
+
+    let mut deser = serde_json::de::Deserializer::from_reader(body.reader());
+
+    serde_path_to_error::deserialize(&mut deser)
+        // intentionally stringify because the debug version is not helpful in python logs
+        .map_err(|e| anyhow::anyhow!("Failed to parse json request: {e}"))
         .map(Some)
         .map_err(ApiError::BadRequest)
 }

libs/utils/src/logging.rs

@@ -1,6 +1,7 @@
 use std::str::FromStr;
 
 use anyhow::Context;
+use metrics::{IntCounter, IntCounterVec};
 use once_cell::sync::Lazy;
 use strum_macros::{EnumString, EnumVariantNames};
 
@@ -24,16 +25,48 @@ impl LogFormat {
     }
 }
 
-static TRACING_EVENT_COUNT: Lazy<metrics::IntCounterVec> = Lazy::new(|| {
-    metrics::register_int_counter_vec!(
+struct TracingEventCountMetric {
+    error: IntCounter,
+    warn: IntCounter,
+    info: IntCounter,
+    debug: IntCounter,
+    trace: IntCounter,
+}
+
+static TRACING_EVENT_COUNT_METRIC: Lazy<TracingEventCountMetric> = Lazy::new(|| {
+    let vec = metrics::register_int_counter_vec!(
         "libmetrics_tracing_event_count",
         "Number of tracing events, by level",
         &["level"]
     )
-    .expect("failed to define metric")
+    .expect("failed to define metric");
+    TracingEventCountMetric::new(vec)
 });
 
-struct TracingEventCountLayer(&'static metrics::IntCounterVec);
+impl TracingEventCountMetric {
+    fn new(vec: IntCounterVec) -> Self {
+        Self {
+            error: vec.with_label_values(&["error"]),
+            warn: vec.with_label_values(&["warn"]),
+            info: vec.with_label_values(&["info"]),
+            debug: vec.with_label_values(&["debug"]),
+            trace: vec.with_label_values(&["trace"]),
+        }
+    }
+
+    fn inc_for_level(&self, level: tracing::Level) {
+        let counter = match level {
+            tracing::Level::ERROR => &self.error,
+            tracing::Level::WARN => &self.warn,
+            tracing::Level::INFO => &self.info,
+            tracing::Level::DEBUG => &self.debug,
+            tracing::Level::TRACE => &self.trace,
+        };
+        counter.inc();
+    }
+}
+
+struct TracingEventCountLayer(&'static TracingEventCountMetric);
 
 impl<S> tracing_subscriber::layer::Layer<S> for TracingEventCountLayer
 where
@@ -44,15 +77,7 @@ where
         event: &tracing::Event<'_>,
         _ctx: tracing_subscriber::layer::Context<'_, S>,
     ) {
-        let level = event.metadata().level();
-        let level = match *level {
-            tracing::Level::ERROR => "error",
-            tracing::Level::WARN => "warn",
-            tracing::Level::INFO => "info",
-            tracing::Level::DEBUG => "debug",
-            tracing::Level::TRACE => "trace",
-        };
-        self.0.with_label_values(&[level]).inc();
+        self.0.inc_for_level(*event.metadata().level());
     }
 }
 
@@ -106,7 +131,9 @@ pub fn init(
         };
         log_layer.with_filter(rust_log_env_filter())
     });
-    let r = r.with(TracingEventCountLayer(&TRACING_EVENT_COUNT).with_filter(rust_log_env_filter()));
+    let r = r.with(
+        TracingEventCountLayer(&TRACING_EVENT_COUNT_METRIC).with_filter(rust_log_env_filter()),
+    );
     match tracing_error_layer_enablement {
         TracingErrorLayerEnablement::EnableWithRustLogFilter => r
             .with(tracing_error::ErrorLayer::default().with_filter(rust_log_env_filter()))
@@ -257,14 +284,14 @@ impl std::fmt::Debug for SecretString {
 mod tests {
     use metrics::{core::Opts, IntCounterVec};
 
-    use super::TracingEventCountLayer;
+    use crate::logging::{TracingEventCountLayer, TracingEventCountMetric};
 
     #[test]
     fn tracing_event_count_metric() {
         let counter_vec =
             IntCounterVec::new(Opts::new("testmetric", "testhelp"), &["level"]).unwrap();
-        let counter_vec = Box::leak(Box::new(counter_vec)); // make it 'static
-        let layer = TracingEventCountLayer(counter_vec);
+        let metric = Box::leak(Box::new(TracingEventCountMetric::new(counter_vec.clone())));
+        let layer = TracingEventCountLayer(metric);
         use tracing_subscriber::prelude::*;
 
         tracing::subscriber::with_default(tracing_subscriber::registry().with(layer), || {

libs/walproposer/src/walproposer.rs

@@ -436,9 +436,9 @@ mod tests {
                 event_mask: 0,
             }),
             expected_messages: vec![
-                // Greeting(ProposerGreeting { protocol_version: 2, pg_version: 160000, proposer_id: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], system_id: 0, timeline_id: 9e4c8f36063c6c6e93bc20d65a820f3d, tenant_id: 9e4c8f36063c6c6e93bc20d65a820f3d, tli: 1, wal_seg_size: 16777216 })
+                // Greeting(ProposerGreeting { protocol_version: 2, pg_version: 160001, proposer_id: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], system_id: 0, timeline_id: 9e4c8f36063c6c6e93bc20d65a820f3d, tenant_id: 9e4c8f36063c6c6e93bc20d65a820f3d, tli: 1, wal_seg_size: 16777216 })
                 vec![
-                    103, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 113, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                    103, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 1, 113, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 158, 76, 143, 54, 6, 60, 108, 110,
                     147, 188, 32, 214, 90, 130, 15, 61, 158, 76, 143, 54, 6, 60, 108, 110, 147,
                     188, 32, 214, 90, 130, 15, 61, 1, 0, 0, 0, 0, 0, 0, 1,
@@ -478,7 +478,7 @@ mod tests {
         // walproposer will panic when it finishes sync_safekeepers
         std::panic::catch_unwind(|| wp.start()).unwrap_err();
         // validate the resulting LSN
-        assert_eq!(receiver.recv()?, 1337);
+        assert_eq!(receiver.try_recv(), Ok(1337));
         Ok(())
         // drop() will free up resources here
     }

pageserver/Cargo.toml

@@ -36,6 +36,7 @@ humantime.workspace = true
 humantime-serde.workspace = true
 hyper.workspace = true
 itertools.workspace = true
+md5.workspace = true
 nix.workspace = true
 # hack to get the number of worker threads tokio uses
 num_cpus = { version = "1.15" }

pageserver/src/bin/pageserver.rs

@@ -14,7 +14,7 @@ use pageserver::control_plane_client::ControlPlaneClient;
 use pageserver::disk_usage_eviction_task::{self, launch_disk_usage_global_eviction_task};
 use pageserver::metrics::{STARTUP_DURATION, STARTUP_IS_LOADING};
 use pageserver::task_mgr::WALRECEIVER_RUNTIME;
-use pageserver::tenant::TenantSharedResources;
+use pageserver::tenant::{secondary, TenantSharedResources};
 use remote_storage::GenericRemoteStorage;
 use tokio::time::Instant;
 use tracing::*;
@@ -370,18 +370,13 @@ fn start_pageserver(
     // Top-level cancellation token for the process
     let shutdown_pageserver = tokio_util::sync::CancellationToken::new();
 
-    pageserver::PAGESERVER_SHUTDOWN_TOKEN
-        .set(shutdown_pageserver.clone())
-        .map_err(|_| ())
-        .expect("cannot be set already");
-
     // Set up remote storage client
     let remote_storage = create_remote_storage_client(conf)?;
 
     // Set up deletion queue
     let (deletion_queue, deletion_workers) = DeletionQueue::new(
         remote_storage.clone(),
-        ControlPlaneClient::new(conf, shutdown_pageserver.child_token()),
+        ControlPlaneClient::new(conf, &shutdown_pageserver),
         conf,
     );
     if let Some(deletion_workers) = deletion_workers {
@@ -425,12 +420,12 @@ fn start_pageserver(
             deletion_queue_client,
         },
         order,
-        shutdown_pageserver.child_token(),
+        shutdown_pageserver.clone(),
     ))?;
     let tenant_manager = Arc::new(tenant_manager);
 
     BACKGROUND_RUNTIME.spawn({
-        let shutdown_pageserver = shutdown_pageserver.child_token();
+        let shutdown_pageserver = shutdown_pageserver.clone();
         let drive_init = async move {
             // NOTE: unlike many futures in pageserver, this one is cancellation-safe
             let guard = scopeguard::guard_on_success((), |_| {
@@ -509,6 +504,17 @@ fn start_pageserver(
         }
     });
 
+    let secondary_controller = if let Some(remote_storage) = &remote_storage {
+        secondary::spawn_tasks(
+            tenant_manager.clone(),
+            remote_storage.clone(),
+            background_jobs_barrier.clone(),
+            shutdown_pageserver.clone(),
+        )
+    } else {
+        secondary::null_controller()
+    };
+
     // shared state between the disk-usage backed eviction background task and the http endpoint
     // that allows triggering disk-usage based eviction manually. note that the http endpoint
     // is still accessible even if background task is not configured as long as remote storage has
@@ -521,7 +527,6 @@ fn start_pageserver(
             remote_storage.clone(),
             disk_usage_eviction_state.clone(),
             background_jobs_barrier.clone(),
-            shutdown_pageserver.child_token(),
         )?;
     }
 
@@ -539,19 +544,17 @@ fn start_pageserver(
                 broker_client.clone(),
                 disk_usage_eviction_state,
                 deletion_queue.new_client(),
+                secondary_controller,
             )
             .context("Failed to initialize router state")?,
         );
-
-        let cancel = shutdown_pageserver.child_token();
-
         let router = http::make_router(router_state, launch_ts, http_auth.clone())?
             .build()
             .map_err(|err| anyhow!(err))?;
         let service = utils::http::RouterService::new(router).unwrap();
         let server = hyper::Server::from_tcp(http_listener)?
             .serve(service)
-            .with_graceful_shutdown(cancel.clone().cancelled_owned());
+            .with_graceful_shutdown(task_mgr::shutdown_watcher());
 
         task_mgr::spawn(
             MGMT_REQUEST_RUNTIME.handle(),
@@ -560,7 +563,6 @@ fn start_pageserver(
             None,
             "http endpoint listener",
             true,
-            cancel,
             async {
                 server.await?;
                 Ok(())
@@ -586,7 +588,6 @@ fn start_pageserver(
             None,
             "consumption metrics collection",
             true,
-            shutdown_pageserver.child_token(),
             async move {
                 // first wait until background jobs are cleared to launch.
                 //
@@ -635,7 +636,6 @@ fn start_pageserver(
             None,
             "libpq endpoint listener",
             true,
-            shutdown_pageserver.child_token(),
             async move {
                 page_service::libpq_listener_main(
                     conf,
@@ -669,8 +669,9 @@ fn start_pageserver(
                 signal.name()
             );
 
-            // This cancels the `shutdown_pageserver` cancellation tree and signals cancellation to
-            // all tasks in the system.
+            // This cancels the `shutdown_pageserver` cancellation tree.
+            // Right now that tree doesn't reach very far, and `task_mgr` is used instead.
+            // The plan is to change that over time.
             shutdown_pageserver.take();
             let bg_remote_storage = remote_storage.clone();
             let bg_deletion_queue = deletion_queue.clone();

pageserver/src/config.rs

@@ -70,6 +70,8 @@ pub mod defaults {
     pub const DEFAULT_SYNTHETIC_SIZE_CALCULATION_INTERVAL: &str = "10 min";
     pub const DEFAULT_BACKGROUND_TASK_MAXIMUM_DELAY: &str = "10s";
 
+    pub const DEFAULT_HEATMAP_UPLOAD_CONCURRENCY: usize = 8;
+
     ///
     /// Default built-in configuration file.
     ///
@@ -117,6 +119,8 @@ pub mod defaults {
 #evictions_low_residence_duration_metric_threshold = '{DEFAULT_EVICTIONS_LOW_RESIDENCE_DURATION_METRIC_THRESHOLD}'
 #gc_feedback = false
 
+#heatmap_upload_concurrency = {DEFAULT_HEATMAP_UPLOAD_CONCURRENCY}
+
 [remote_storage]
 
 "#
@@ -215,6 +219,10 @@ pub struct PageServerConf {
     /// If true, pageserver will make best-effort to operate without a control plane: only
     /// for use in major incidents.
     pub control_plane_emergency_mode: bool,
+
+    /// How many heatmap uploads may be done concurrency: lower values implicitly deprioritize
+    /// heatmap uploads vs. other remote storage operations.
+    pub heatmap_upload_concurrency: usize,
 }
 
 /// We do not want to store this in a PageServerConf because the latter may be logged
@@ -293,6 +301,8 @@ struct PageServerConfigBuilder {
     control_plane_api: BuilderValue<Option<Url>>,
     control_plane_api_token: BuilderValue<Option<SecretString>>,
     control_plane_emergency_mode: BuilderValue<bool>,
+
+    heatmap_upload_concurrency: BuilderValue<usize>,
 }
 
 impl Default for PageServerConfigBuilder {
@@ -361,6 +371,8 @@ impl Default for PageServerConfigBuilder {
             control_plane_api: Set(None),
             control_plane_api_token: Set(None),
             control_plane_emergency_mode: Set(false),
+
+            heatmap_upload_concurrency: Set(DEFAULT_HEATMAP_UPLOAD_CONCURRENCY),
         }
     }
 }
@@ -501,6 +513,10 @@ impl PageServerConfigBuilder {
         self.control_plane_emergency_mode = BuilderValue::Set(enabled)
     }
 
+    pub fn heatmap_upload_concurrency(&mut self, value: usize) {
+        self.heatmap_upload_concurrency = BuilderValue::Set(value)
+    }
+
     pub fn build(self) -> anyhow::Result<PageServerConf> {
         let concurrent_tenant_size_logical_size_queries = self
             .concurrent_tenant_size_logical_size_queries
@@ -595,6 +611,10 @@ impl PageServerConfigBuilder {
             control_plane_emergency_mode: self
                 .control_plane_emergency_mode
                 .ok_or(anyhow!("missing control_plane_emergency_mode"))?,
+
+            heatmap_upload_concurrency: self
+                .heatmap_upload_concurrency
+                .ok_or(anyhow!("missing heatmap_upload_concurrency"))?,
         })
     }
 }
@@ -828,7 +848,9 @@ impl PageServerConf {
                 },
                 "control_plane_emergency_mode" => {
                     builder.control_plane_emergency_mode(parse_toml_bool(key, item)?)
-
+                },
+                "heatmap_upload_concurrency" => {
+                    builder.heatmap_upload_concurrency(parse_toml_u64(key, item)? as usize)
                 },
                 _ => bail!("unrecognized pageserver option '{key}'"),
             }
@@ -896,6 +918,7 @@ impl PageServerConf {
             control_plane_api: None,
             control_plane_api_token: None,
             control_plane_emergency_mode: false,
+            heatmap_upload_concurrency: defaults::DEFAULT_HEATMAP_UPLOAD_CONCURRENCY,
         }
     }
 }
@@ -1120,7 +1143,8 @@ background_task_maximum_delay = '334 s'
                 )?,
                 control_plane_api: None,
                 control_plane_api_token: None,
-                control_plane_emergency_mode: false
+                control_plane_emergency_mode: false,
+                heatmap_upload_concurrency: defaults::DEFAULT_HEATMAP_UPLOAD_CONCURRENCY
             },
             "Correct defaults should be used when no config values are provided"
         );
@@ -1177,7 +1201,8 @@ background_task_maximum_delay = '334 s'
                 background_task_maximum_delay: Duration::from_secs(334),
                 control_plane_api: None,
                 control_plane_api_token: None,
-                control_plane_emergency_mode: false
+                control_plane_emergency_mode: false,
+                heatmap_upload_concurrency: defaults::DEFAULT_HEATMAP_UPLOAD_CONCURRENCY
             },
             "Should be able to parse all basic config values correctly"
         );

pageserver/src/consumption_metrics.rs

@@ -65,7 +65,6 @@ pub async fn collect_metrics(
         None,
         "synthetic size calculation",
         false,
-        cancel.child_token(),
         async move {
             calculate_synthetic_size_worker(
                 synthetic_size_calculation_interval,

pageserver/src/control_plane_client.rs

@@ -40,7 +40,7 @@ pub trait ControlPlaneGenerationsApi {
 impl ControlPlaneClient {
     /// A None return value indicates that the input `conf` object does not have control
     /// plane API enabled.
-    pub fn new(conf: &'static PageServerConf, cancel: CancellationToken) -> Option<Self> {
+    pub fn new(conf: &'static PageServerConf, cancel: &CancellationToken) -> Option<Self> {
         let mut url = match conf.control_plane_api.as_ref() {
             Some(u) => u.clone(),
             None => return None,
@@ -67,7 +67,7 @@ impl ControlPlaneClient {
             http_client: client.build().expect("Failed to construct HTTP client"),
             base_url: url,
             node_id: conf.id,
-            cancel,
+            cancel: cancel.clone(),
         })
     }
 

pageserver/src/disk_usage_eviction_task.rs

@@ -87,7 +87,6 @@ pub fn launch_disk_usage_global_eviction_task(
     storage: GenericRemoteStorage,
     state: Arc<State>,
     background_jobs_barrier: completion::Barrier,
-    cancel: CancellationToken,
 ) -> anyhow::Result<()> {
     let Some(task_config) = &conf.disk_usage_based_eviction else {
         info!("disk usage based eviction task not configured");
@@ -103,7 +102,6 @@ pub fn launch_disk_usage_global_eviction_task(
         None,
         "disk usage based eviction",
         false,
-        cancel,
         async move {
             let cancel = task_mgr::shutdown_token();
 

pageserver/src/http/openapi_spec.yml

@@ -992,8 +992,8 @@ paths:
           type: string
     post:
       description: |
-        Create a timeline. Returns new timeline id on success.\
-        If no new timeline id is specified in parameters, it would be generated. It's an error to recreate the same timeline.
+        Create a timeline. Returns new timeline id on success.
+        Recreating the same timeline will succeed if the parameters match the existing timeline.
         If no pg_version is specified, assume DEFAULT_PG_VERSION hardcoded in the pageserver.
       requestBody:
         content:
@@ -1405,6 +1405,8 @@ components:
           type: integer
         trace_read_requests:
           type: boolean
+        heatmap_period:
+          type: integer
     TenantConfigResponse:
       type: object
       properties:

pageserver/src/http/routes.rs

@@ -42,6 +42,7 @@ use crate::tenant::mgr::{
     GetTenantError, SetNewTenantConfigError, TenantManager, TenantMapError, TenantMapInsertError,
     TenantSlotError, TenantSlotUpsertError, TenantStateError,
 };
+use crate::tenant::secondary::SecondaryController;
 use crate::tenant::size::ModelInputs;
 use crate::tenant::storage_layer::LayerAccessStatsReset;
 use crate::tenant::timeline::CompactFlags;
@@ -75,9 +76,11 @@ pub struct State {
     broker_client: storage_broker::BrokerClientChannel,
     disk_usage_eviction_state: Arc<disk_usage_eviction_task::State>,
     deletion_queue_client: DeletionQueueClient,
+    secondary_controller: SecondaryController,
 }
 
 impl State {
+    #[allow(clippy::too_many_arguments)]
     pub fn new(
         conf: &'static PageServerConf,
         tenant_manager: Arc<TenantManager>,
@@ -86,6 +89,7 @@ impl State {
         broker_client: storage_broker::BrokerClientChannel,
         disk_usage_eviction_state: Arc<disk_usage_eviction_task::State>,
         deletion_queue_client: DeletionQueueClient,
+        secondary_controller: SecondaryController,
     ) -> anyhow::Result<Self> {
         let allowlist_routes = ["/v1/status", "/v1/doc", "/swagger.yml", "/metrics"]
             .iter()
@@ -100,6 +104,7 @@ impl State {
             broker_client,
             disk_usage_eviction_state,
             deletion_queue_client,
+            secondary_controller,
         })
     }
 
@@ -448,7 +453,7 @@ async fn timeline_create_handler(
                     .map_err(ApiError::InternalServerError)?;
                 json_response(StatusCode::CREATED, timeline_info)
             }
-            Err(tenant::CreateTimelineError::AlreadyExists) => {
+            Err(tenant::CreateTimelineError::Conflict | tenant::CreateTimelineError::AlreadyCreating) => {
                 json_response(StatusCode::CONFLICT, ())
             }
             Err(tenant::CreateTimelineError::AncestorLsn(err)) => {
@@ -1616,9 +1621,7 @@ async fn disk_usage_eviction_run(
         }
     }
 
-    let config = json_request::<Config>(&mut r)
-        .await
-        .map_err(|_| ApiError::BadRequest(anyhow::anyhow!("invalid JSON body")))?;
+    let config = json_request::<Config>(&mut r).await?;
 
     let usage = Usage {
         config,
@@ -1647,6 +1650,21 @@ async fn disk_usage_eviction_run(
     json_response(StatusCode::OK, res)
 }
 
+async fn secondary_upload_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")?;
+    state
+        .secondary_controller
+        .upload_tenant(tenant_shard_id)
+        .await
+        .map_err(ApiError::InternalServerError)?;
+
+    json_response(StatusCode::OK, ())
+}
+
 async fn handler_404(_: Request<Body>) -> Result<Response<Body>, ApiError> {
     json_response(
         StatusCode::NOT_FOUND,
@@ -1906,6 +1924,9 @@ pub fn make_router(
             "/v1/tenant/:tenant_shard_id/timeline/:timeline_id/layer/:layer_file_name",
             |r| api_handler(r, evict_timeline_layer_handler),
         )
+        .post("/v1/tenant/:tenant_shard_id/heatmap_upload", |r| {
+            api_handler(r, secondary_upload_handler)
+        })
         .put("/v1/disk_usage_eviction/run", |r| {
             api_handler(r, disk_usage_eviction_run)
         })

pageserver/src/lib.rs

@@ -49,22 +49,11 @@ pub const DELTA_FILE_MAGIC: u16 = 0x5A61;
 
 static ZERO_PAGE: bytes::Bytes = bytes::Bytes::from_static(&[0u8; 8192]);
 
-/// The main cancellation token for the process.
-///
-/// Should only ever be used to create child tokens.
-pub static PAGESERVER_SHUTDOWN_TOKEN: std::sync::OnceLock<tokio_util::sync::CancellationToken> =
-    std::sync::OnceLock::new();
-
 pub use crate::metrics::preinitialize_metrics;
 
 #[tracing::instrument(skip_all, fields(%exit_code))]
 pub async fn shutdown_pageserver(deletion_queue: Option<DeletionQueue>, exit_code: i32) {
     use std::time::Duration;
-
-    if let Some(token) = PAGESERVER_SHUTDOWN_TOKEN.get() {
-        token.cancel();
-    }
-
     // Shut down the libpq endpoint task. This prevents new connections from
     // being accepted.
     timed(

pageserver/src/metrics.rs

@@ -2,9 +2,10 @@ use enum_map::EnumMap;
 use metrics::metric_vec_duration::DurationResultObserver;
 use metrics::{
     register_counter_vec, register_gauge_vec, register_histogram, register_histogram_vec,
-    register_int_counter, register_int_counter_vec, register_int_gauge, register_int_gauge_vec,
-    register_uint_gauge, register_uint_gauge_vec, Counter, CounterVec, GaugeVec, Histogram,
-    HistogramVec, IntCounter, IntCounterVec, IntGauge, IntGaugeVec, UIntGauge, UIntGaugeVec,
+    register_int_counter, register_int_counter_pair_vec, register_int_counter_vec,
+    register_int_gauge, register_int_gauge_vec, register_uint_gauge, register_uint_gauge_vec,
+    Counter, CounterVec, GaugeVec, Histogram, HistogramVec, IntCounter, IntCounterPairVec,
+    IntCounterVec, IntGauge, IntGaugeVec, UIntGauge, UIntGaugeVec,
 };
 use once_cell::sync::Lazy;
 use pageserver_api::shard::TenantShardId;
@@ -1270,6 +1271,28 @@ pub(crate) static WAL_INGEST: Lazy<WalIngestMetrics> = Lazy::new(|| WalIngestMet
     )
     .expect("failed to define a metric"),
 });
+pub(crate) struct SecondaryModeMetrics {
+    pub(crate) upload_heatmap: IntCounter,
+    pub(crate) upload_heatmap_errors: IntCounter,
+    pub(crate) upload_heatmap_duration: Histogram,
+}
+pub(crate) static SECONDARY_MODE: Lazy<SecondaryModeMetrics> = Lazy::new(|| SecondaryModeMetrics {
+    upload_heatmap: register_int_counter!(
+        "pageserver_secondary_upload_heatmap",
+        "Number of heatmaps written to remote storage by attached tenants"
+    )
+    .expect("failed to define a metric"),
+    upload_heatmap_errors: register_int_counter!(
+        "pageserver_secondary_upload_heatmap_errors",
+        "Failures writing heatmap to remote storage"
+    )
+    .expect("failed to define a metric"),
+    upload_heatmap_duration: register_histogram!(
+        "pageserver_secondary_upload_heatmap_duration",
+        "Time to build and upload a heatmap, including any waiting inside the S3 client"
+    )
+    .expect("failed to define a metric"),
+});
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum RemoteOpKind {
@@ -1321,25 +1344,16 @@ pub(crate) static TENANT_TASK_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
     .expect("Failed to register tenant_task_events metric")
 });
 
-pub(crate) static BACKGROUND_LOOP_SEMAPHORE_WAIT_START_COUNT: Lazy<IntCounterVec> =
-    Lazy::new(|| {
-        register_int_counter_vec!(
-            "pageserver_background_loop_semaphore_wait_start_count",
-            "Counter for background loop concurrency-limiting semaphore acquire calls started",
-            &["task"],
-        )
-        .unwrap()
-    });
-
-pub(crate) static BACKGROUND_LOOP_SEMAPHORE_WAIT_FINISH_COUNT: Lazy<IntCounterVec> =
-    Lazy::new(|| {
-        register_int_counter_vec!(
-            "pageserver_background_loop_semaphore_wait_finish_count",
-            "Counter for background loop concurrency-limiting semaphore acquire calls finished",
-            &["task"],
-        )
-        .unwrap()
-    });
+pub(crate) static BACKGROUND_LOOP_SEMAPHORE_WAIT_GAUGE: Lazy<IntCounterPairVec> = Lazy::new(|| {
+    register_int_counter_pair_vec!(
+        "pageserver_background_loop_semaphore_wait_start_count",
+        "Counter for background loop concurrency-limiting semaphore acquire calls started",
+        "pageserver_background_loop_semaphore_wait_finish_count",
+        "Counter for background loop concurrency-limiting semaphore acquire calls finished",
+        &["task"],
+    )
+    .unwrap()
+});
 
 pub(crate) static BACKGROUND_LOOP_PERIOD_OVERRUN_COUNT: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(

pageserver/src/page_service.rs

@@ -166,7 +166,6 @@ pub async fn libpq_listener_main(
                     None,
                     "serving compute connection task",
                     false,
-                    cancel.child_token(),
                     page_service_conn_main(
                         conf,
                         broker_client.clone(),

pageserver/src/task_mgr.rs

@@ -258,6 +258,9 @@ pub enum TaskKind {
     /// See [`crate::disk_usage_eviction_task`].
     DiskUsageEviction,
 
+    /// See [`crate::tenant::secondary`].
+    SecondaryUploads,
+
     // Initial logical size calculation
     InitialLogicalSizeCalculation,
 
@@ -327,7 +330,6 @@ struct PageServerTask {
 /// Launch a new task
 /// Note: if shutdown_process_on_error is set to true failure
 ///   of the task will lead to shutdown of entire process
-#[allow(clippy::too_many_arguments)]
 pub fn spawn<F>(
     runtime: &tokio::runtime::Handle,
     kind: TaskKind,
@@ -335,13 +337,12 @@ pub fn spawn<F>(
     timeline_id: Option<TimelineId>,
     name: &str,
     shutdown_process_on_error: bool,
-    cancel: CancellationToken,
     future: F,
 ) -> PageserverTaskId
 where
     F: Future<Output = anyhow::Result<()>> + Send + 'static,
 {
-    // let cancel = CancellationToken::new();
+    let cancel = CancellationToken::new();
     let task_id = NEXT_TASK_ID.fetch_add(1, Ordering::Relaxed);
     let task = Arc::new(PageServerTask {
         task_id: PageserverTaskId(task_id),
@@ -563,9 +564,9 @@ pub fn shutdown_token() -> CancellationToken {
     let res = SHUTDOWN_TOKEN.try_with(|t| t.clone());
 
     if cfg!(test) {
+        // in tests this method is called from non-taskmgr spawned tasks, and that is all ok.
         res.unwrap_or_default()
     } else {
-        // tests need to call the same paths which need to use get the shutdown token
         res.expect("shutdown_token() called in an unexpected task or thread")
     }
 }

pageserver/src/tenant.rs

@@ -48,6 +48,7 @@ use self::mgr::GetActiveTenantError;
 use self::mgr::GetTenantError;
 use self::mgr::TenantsMap;
 use self::remote_timeline_client::RemoteTimelineClient;
+use self::timeline::uninit::TimelineExclusionError;
 use self::timeline::uninit::TimelineUninitMark;
 use self::timeline::uninit::UninitializedTimeline;
 use self::timeline::EvictionTaskTenantState;
@@ -87,7 +88,6 @@ use std::process::Stdio;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
 use std::sync::Arc;
-use std::sync::MutexGuard;
 use std::sync::{Mutex, RwLock};
 use std::time::{Duration, Instant};
 
@@ -144,6 +144,7 @@ pub mod storage_layer;
 pub mod config;
 pub mod delete;
 pub mod mgr;
+pub mod secondary;
 pub mod tasks;
 pub mod upload_queue;
 
@@ -248,6 +249,12 @@ pub struct Tenant {
     generation: Generation,
 
     timelines: Mutex<HashMap<TimelineId, Arc<Timeline>>>,
+
+    /// During timeline creation, we first insert the TimelineId to the
+    /// creating map, then `timelines`, then remove it from the creating map.
+    /// **Lock order**: if acquring both, acquire`timelines` before `timelines_creating`
+    timelines_creating: std::sync::Mutex<HashSet<TimelineId>>,
+
     // This mutex prevents creation of new timelines during GC.
     // Adding yet another mutex (in addition to `timelines`) is needed because holding
     // `timelines` mutex during all GC iteration
@@ -406,8 +413,10 @@ impl Debug for SetStoppingError {
 
 #[derive(thiserror::Error, Debug)]
 pub enum CreateTimelineError {
-    #[error("a timeline with the given ID already exists")]
-    AlreadyExists,
+    #[error("creation of timeline with the given ID is in progress")]
+    AlreadyCreating,
+    #[error("timeline already exists with different parameters")]
+    Conflict,
     #[error(transparent)]
     AncestorLsn(anyhow::Error),
     #[error("ancestor timeline is not active")]
@@ -486,7 +495,6 @@ impl Tenant {
             ancestor.clone(),
             resources,
             CreateTimelineCause::Load,
-            self.cancel.child_token(),
         )?;
         let disk_consistent_lsn = timeline.get_disk_consistent_lsn();
         anyhow::ensure!(
@@ -504,7 +512,7 @@ impl Tenant {
                 .remote_client
                 .as_ref()
                 .unwrap()
-                .init_upload_queue(index_part, timeline.cancel.child_token())?;
+                .init_upload_queue(index_part)?;
         } else if self.remote_storage.is_some() {
             // No data on the remote storage, but we have local metadata file. We can end up
             // here with timeline_create being interrupted before finishing index part upload.
@@ -512,7 +520,7 @@ impl Tenant {
             // If control plane retries timeline creation in the meantime, the mgmt API handler
             // for timeline creation will coalesce on the upload we queue here.
             let rtc = timeline.remote_client.as_ref().unwrap();
-            rtc.init_upload_queue_for_empty_remote(&metadata, timeline.cancel.child_token())?;
+            rtc.init_upload_queue_for_empty_remote(&metadata)?;
             rtc.schedule_index_upload_for_metadata_update(&metadata)?;
         }
 
@@ -606,12 +614,6 @@ impl Tenant {
         let tenant_clone = Arc::clone(&tenant);
 
         let ctx = ctx.detached_child(TaskKind::Attach, DownloadBehavior::Warn);
-        let cancel = crate::PAGESERVER_SHUTDOWN_TOKEN
-            .get()
-            .cloned()
-            .unwrap_or_default()
-            .child_token();
-
         task_mgr::spawn(
             &tokio::runtime::Handle::current(),
             TaskKind::Attach,
@@ -619,7 +621,6 @@ impl Tenant {
             None,
             "attach tenant",
             false,
-            cancel,
             async move {
                 // Ideally we should use Tenant::set_broken_no_wait, but it is not supposed to be used when tenant is in loading state.
                 let make_broken =
@@ -879,10 +880,8 @@ impl Tenant {
 
         // Walk through deleted timelines, resume deletion
         for (timeline_id, index_part, remote_timeline_client) in timelines_to_resume_deletions {
-            let cancel = self.cancel.child_token();
-
             remote_timeline_client
-                .init_upload_queue_stopped_to_continue_deletion(&index_part, cancel.child_token())
+                .init_upload_queue_stopped_to_continue_deletion(&index_part)
                 .context("init queue stopped")
                 .map_err(LoadLocalTimelineError::ResumeDeletion)?;
 
@@ -892,7 +891,6 @@ impl Tenant {
                 &index_part.metadata,
                 Some(remote_timeline_client),
                 self.deletion_queue_client.clone(),
-                cancel,
             )
             .await
             .context("resume_deletion")
@@ -1226,7 +1224,7 @@ impl Tenant {
                 timeline_id,
                 self.generation,
             );
-            let cancel_clone = cancel.child_token();
+            let cancel_clone = cancel.clone();
             part_downloads.spawn(
                 async move {
                     debug!("starting index part download");
@@ -1387,7 +1385,6 @@ impl Tenant {
                 &local_metadata,
                 None,
                 self.deletion_queue_client.clone(),
-                self.cancel.child_token(),
             )
             .await
             .context("resume deletion")
@@ -1469,7 +1466,7 @@ impl Tenant {
     /// For tests, use `DatadirModification::init_empty_test_timeline` + `commit` to setup the
     /// minimum amount of keys required to get a writable timeline.
     /// (Without it, `put` might fail due to `repartition` failing.)
-    pub async fn create_empty_timeline(
+    pub(crate) async fn create_empty_timeline(
         &self,
         new_timeline_id: TimelineId,
         initdb_lsn: Lsn,
@@ -1481,10 +1478,7 @@ impl Tenant {
             "Cannot create empty timelines on inactive tenant"
         );
 
-        let timeline_uninit_mark = {
-            let timelines = self.timelines.lock().unwrap();
-            self.create_timeline_uninit_mark(new_timeline_id, &timelines)?
-        };
+        let timeline_uninit_mark = self.create_timeline_uninit_mark(new_timeline_id)?;
         let new_metadata = TimelineMetadata::new(
             // Initialize disk_consistent LSN to 0, The caller must import some data to
             // make it valid, before calling finish_creation()
@@ -1561,7 +1555,7 @@ impl Tenant {
     /// If the caller specified the timeline ID to use (`new_timeline_id`), and timeline with
     /// the same timeline ID already exists, returns CreateTimelineError::AlreadyExists.
     #[allow(clippy::too_many_arguments)]
-    pub async fn create_timeline(
+    pub(crate) async fn create_timeline(
         &self,
         new_timeline_id: TimelineId,
         ancestor_timeline_id: Option<TimelineId>,
@@ -1582,26 +1576,51 @@ impl Tenant {
             .enter()
             .map_err(|_| CreateTimelineError::ShuttingDown)?;
 
-        if let Ok(existing) = self.get_timeline(new_timeline_id, false) {
-            debug!("timeline {new_timeline_id} already exists");
-
-            if let Some(remote_client) = existing.remote_client.as_ref() {
-                // Wait for uploads to complete, so that when we return Ok, the timeline
-                // is known to be durable on remote storage. Just like we do at the end of
-                // this function, after we have created the timeline ourselves.
-                //
-                // We only really care that the initial version of `index_part.json` has
-                // been uploaded. That's enough to remember that the timeline
-                // exists. However, there is no function to wait specifically for that so
-                // we just wait for all in-progress uploads to finish.
-                remote_client
-                    .wait_completion()
-                    .await
-                    .context("wait for timeline uploads to complete")?;
+        // Get exclusive access to the timeline ID: this ensures that it does not already exist,
+        // and that no other creation attempts will be allowed in while we are working.  The
+        // uninit_mark is a guard.
+        let uninit_mark = match self.create_timeline_uninit_mark(new_timeline_id) {
+            Ok(m) => m,
+            Err(TimelineExclusionError::AlreadyCreating) => {
+                // Creation is in progress, we cannot create it again, and we cannot
+                // check if this request matches the existing one, so caller must try
+                // again later.
+                return Err(CreateTimelineError::AlreadyCreating);
             }
+            Err(TimelineExclusionError::Other(e)) => {
+                return Err(CreateTimelineError::Other(e));
+            }
+            Err(TimelineExclusionError::AlreadyExists(existing)) => {
+                debug!("timeline {new_timeline_id} already exists");
 
-            return Err(CreateTimelineError::AlreadyExists);
-        }
+                // Idempotency: creating the same timeline twice is not an error, unless
+                // the second creation has different parameters.
+                if existing.get_ancestor_timeline_id() != ancestor_timeline_id
+                    || existing.pg_version != pg_version
+                    || (ancestor_start_lsn.is_some()
+                        && ancestor_start_lsn != Some(existing.get_ancestor_lsn()))
+                {
+                    return Err(CreateTimelineError::Conflict);
+                }
+
+                if let Some(remote_client) = existing.remote_client.as_ref() {
+                    // Wait for uploads to complete, so that when we return Ok, the timeline
+                    // is known to be durable on remote storage. Just like we do at the end of
+                    // this function, after we have created the timeline ourselves.
+                    //
+                    // We only really care that the initial version of `index_part.json` has
+                    // been uploaded. That's enough to remember that the timeline
+                    // exists. However, there is no function to wait specifically for that so
+                    // we just wait for all in-progress uploads to finish.
+                    remote_client
+                        .wait_completion()
+                        .await
+                        .context("wait for timeline uploads to complete")?;
+                }
+
+                return Ok(existing);
+            }
+        };
 
         let loaded_timeline = match ancestor_timeline_id {
             Some(ancestor_timeline_id) => {
@@ -1638,18 +1657,32 @@ impl Tenant {
                     ancestor_timeline.wait_lsn(*lsn, ctx).await?;
                 }
 
-                self.branch_timeline(&ancestor_timeline, new_timeline_id, ancestor_start_lsn, ctx)
-                    .await?
+                self.branch_timeline(
+                    &ancestor_timeline,
+                    new_timeline_id,
+                    ancestor_start_lsn,
+                    uninit_mark,
+                    ctx,
+                )
+                .await?
             }
             None => {
-                self.bootstrap_timeline(new_timeline_id, pg_version, load_existing_initdb, ctx)
-                    .await?
+                self.bootstrap_timeline(
+                    new_timeline_id,
+                    pg_version,
+                    load_existing_initdb,
+                    uninit_mark,
+                    ctx,
+                )
+                .await?
             }
         };
 
+        // At this point we have dropped our guard on [`Self::timelines_creating`], and
+        // the timeline is visible in [`Self::timelines`], but it is _not_ durable yet.  We must
+        // not send a success to the caller until it is.  The same applies to handling retries,
+        // see the handling of [`TimelineExclusionError::AlreadyExists`] above.
         if let Some(remote_client) = loaded_timeline.remote_client.as_ref() {
-            // Wait for the upload of the 'index_part.json` file to finish, so that when we return
-            // Ok, the timeline is durable in remote storage.
             let kind = ancestor_timeline_id
                 .map(|_| "branched")
                 .unwrap_or("bootstrapped");
@@ -2126,6 +2159,14 @@ impl Tenant {
             .attach_mode
             .clone()
     }
+
+    pub(crate) fn get_tenant_shard_id(&self) -> &TenantShardId {
+        &self.tenant_shard_id
+    }
+
+    pub(crate) fn get_generation(&self) -> Generation {
+        self.generation
+    }
 }
 
 /// Given a Vec of timelines and their ancestors (timeline_id, ancestor_id),
@@ -2264,6 +2305,18 @@ impl Tenant {
             .or(self.conf.default_tenant_conf.min_resident_size_override)
     }
 
+    pub fn get_heatmap_period(&self) -> Option<Duration> {
+        let tenant_conf = self.tenant_conf.read().unwrap().tenant_conf;
+        let heatmap_period = tenant_conf
+            .heatmap_period
+            .unwrap_or(self.conf.default_tenant_conf.heatmap_period);
+        if heatmap_period.is_zero() {
+            None
+        } else {
+            Some(heatmap_period)
+        }
+    }
+
     pub fn set_new_tenant_config(&self, new_tenant_conf: TenantConfOpt) {
         self.tenant_conf.write().unwrap().tenant_conf = new_tenant_conf;
         // Don't hold self.timelines.lock() during the notifies.
@@ -2302,7 +2355,6 @@ impl Tenant {
         ancestor: Option<Arc<Timeline>>,
         resources: TimelineResources,
         cause: CreateTimelineCause,
-        cancel: CancellationToken,
     ) -> anyhow::Result<Arc<Timeline>> {
         let state = match cause {
             CreateTimelineCause::Load => {
@@ -2331,7 +2383,7 @@ impl Tenant {
             resources,
             pg_version,
             state,
-            cancel,
+            self.cancel.child_token(),
         );
 
         Ok(timeline)
@@ -2404,12 +2456,6 @@ impl Tenant {
             }
         });
 
-        let cancel = crate::PAGESERVER_SHUTDOWN_TOKEN
-            .get()
-            .cloned()
-            .unwrap_or_default()
-            .child_token();
-
         Tenant {
             tenant_shard_id,
             shard_identity,
@@ -2420,6 +2466,7 @@ impl Tenant {
             loading_started_at: Instant::now(),
             tenant_conf: Arc::new(RwLock::new(attached_conf)),
             timelines: Mutex::new(HashMap::new()),
+            timelines_creating: Mutex::new(HashSet::new()),
             gc_cs: tokio::sync::Mutex::new(()),
             walredo_mgr,
             remote_storage,
@@ -2429,7 +2476,7 @@ impl Tenant {
             cached_synthetic_tenant_size: Arc::new(AtomicU64::new(0)),
             eviction_task_tenant_state: tokio::sync::Mutex::new(EvictionTaskTenantState::default()),
             delete_progress: Arc::new(tokio::sync::Mutex::new(DeleteTenantFlow::default())),
-            cancel,
+            cancel: CancellationToken::default(),
             gate: Gate::new(format!("Tenant<{tenant_shard_id}>")),
         }
     }
@@ -2811,8 +2858,9 @@ impl Tenant {
         start_lsn: Option<Lsn>,
         ctx: &RequestContext,
     ) -> Result<Arc<Timeline>, CreateTimelineError> {
+        let uninit_mark = self.create_timeline_uninit_mark(dst_id).unwrap();
         let tl = self
-            .branch_timeline_impl(src_timeline, dst_id, start_lsn, ctx)
+            .branch_timeline_impl(src_timeline, dst_id, start_lsn, uninit_mark, ctx)
             .await?;
         tl.set_state(TimelineState::Active);
         Ok(tl)
@@ -2826,9 +2874,10 @@ impl Tenant {
         src_timeline: &Arc<Timeline>,
         dst_id: TimelineId,
         start_lsn: Option<Lsn>,
+        timeline_uninit_mark: TimelineUninitMark<'_>,
         ctx: &RequestContext,
     ) -> Result<Arc<Timeline>, CreateTimelineError> {
-        self.branch_timeline_impl(src_timeline, dst_id, start_lsn, ctx)
+        self.branch_timeline_impl(src_timeline, dst_id, start_lsn, timeline_uninit_mark, ctx)
             .await
     }
 
@@ -2837,13 +2886,14 @@ impl Tenant {
         src_timeline: &Arc<Timeline>,
         dst_id: TimelineId,
         start_lsn: Option<Lsn>,
+        timeline_uninit_mark: TimelineUninitMark<'_>,
         _ctx: &RequestContext,
     ) -> Result<Arc<Timeline>, CreateTimelineError> {
         let src_id = src_timeline.timeline_id;
 
-        // First acquire the GC lock so that another task cannot advance the GC
-        // cutoff in 'gc_info', and make 'start_lsn' invalid, while we are
-        // creating the branch.
+        // We will validate our ancestor LSN in this function.  Acquire the GC lock so that
+        // this check cannot race with GC, and the ancestor LSN is guaranteed to remain
+        // valid while we are creating the branch.
         let _gc_cs = self.gc_cs.lock().await;
 
         // If no start LSN is specified, we branch the new timeline from the source timeline's last record LSN
@@ -2853,13 +2903,6 @@ impl Tenant {
             lsn
         });
 
-        // Create a placeholder for the new branch. This will error
-        // out if the new timeline ID is already in use.
-        let timeline_uninit_mark = {
-            let timelines = self.timelines.lock().unwrap();
-            self.create_timeline_uninit_mark(dst_id, &timelines)?
-        };
-
         // Ensure that `start_lsn` is valid, i.e. the LSN is within the PITR
         // horizon on the source timeline
         //
@@ -2951,21 +2994,38 @@ impl Tenant {
         Ok(new_timeline)
     }
 
-    /// - run initdb to init temporary instance and get bootstrap data
-    /// - after initialization completes, tar up the temp dir and upload it to S3.
-    ///
-    /// The caller is responsible for activating the returned timeline.
-    pub(crate) async fn bootstrap_timeline(
+    /// For unit tests, make this visible so that other modules can directly create timelines
+    #[cfg(test)]
+    pub(crate) async fn bootstrap_timeline_test(
         &self,
         timeline_id: TimelineId,
         pg_version: u32,
         load_existing_initdb: Option<TimelineId>,
         ctx: &RequestContext,
     ) -> anyhow::Result<Arc<Timeline>> {
-        let timeline_uninit_mark = {
-            let timelines = self.timelines.lock().unwrap();
-            self.create_timeline_uninit_mark(timeline_id, &timelines)?
-        };
+        let uninit_mark = self.create_timeline_uninit_mark(timeline_id).unwrap();
+        self.bootstrap_timeline(
+            timeline_id,
+            pg_version,
+            load_existing_initdb,
+            uninit_mark,
+            ctx,
+        )
+        .await
+    }
+
+    /// - run initdb to init temporary instance and get bootstrap data
+    /// - after initialization completes, tar up the temp dir and upload it to S3.
+    ///
+    /// The caller is responsible for activating the returned timeline.
+    async fn bootstrap_timeline(
+        &self,
+        timeline_id: TimelineId,
+        pg_version: u32,
+        load_existing_initdb: Option<TimelineId>,
+        timeline_uninit_mark: TimelineUninitMark<'_>,
+        ctx: &RequestContext,
+    ) -> anyhow::Result<Arc<Timeline>> {
         // create a `tenant/{tenant_id}/timelines/basebackup-{timeline_id}.{TEMP_FILE_SUFFIX}/`
         // temporary directory for basebackup files for the given timeline.
 
@@ -3046,8 +3106,9 @@ impl Tenant {
                     3,
                     u32::MAX,
                     "persist_initdb_tar_zst",
-                    // TODO: use a cancellation token (https://github.com/neondatabase/neon/issues/5066)
-                    backoff::Cancel::new(CancellationToken::new(), || unreachable!()),
+                    backoff::Cancel::new(self.cancel.clone(), || {
+                        anyhow::anyhow!("initdb upload cancelled")
+                    }),
                 )
                 .await?;
 
@@ -3162,22 +3223,19 @@ impl Tenant {
     /// at 'disk_consistent_lsn'. After any initial data has been imported, call
     /// `finish_creation` to insert the Timeline into the timelines map and to remove the
     /// uninit mark file.
-    async fn prepare_new_timeline(
-        &self,
+    async fn prepare_new_timeline<'a>(
+        &'a self,
         new_timeline_id: TimelineId,
         new_metadata: &TimelineMetadata,
-        uninit_mark: TimelineUninitMark,
+        uninit_mark: TimelineUninitMark<'a>,
         start_lsn: Lsn,
         ancestor: Option<Arc<Timeline>>,
     ) -> anyhow::Result<UninitializedTimeline> {
         let tenant_shard_id = self.tenant_shard_id;
 
         let resources = self.build_timeline_resources(new_timeline_id);
-
-        let cancel = self.cancel.child_token();
-
         if let Some(remote_client) = &resources.remote_client {
-            remote_client.init_upload_queue_for_empty_remote(new_metadata, cancel.child_token())?;
+            remote_client.init_upload_queue_for_empty_remote(new_metadata)?;
         }
 
         let timeline_struct = self
@@ -3187,7 +3245,6 @@ impl Tenant {
                 ancestor,
                 resources,
                 CreateTimelineCause::Load,
-                cancel,
             )
             .context("Failed to create timeline data structure")?;
 
@@ -3243,23 +3300,38 @@ impl Tenant {
     fn create_timeline_uninit_mark(
         &self,
         timeline_id: TimelineId,
-        timelines: &MutexGuard<HashMap<TimelineId, Arc<Timeline>>>,
-    ) -> anyhow::Result<TimelineUninitMark> {
+    ) -> Result<TimelineUninitMark, TimelineExclusionError> {
         let tenant_shard_id = self.tenant_shard_id;
 
-        anyhow::ensure!(
-            timelines.get(&timeline_id).is_none(),
-            "Timeline {tenant_shard_id}/{timeline_id} already exists in pageserver's memory"
-        );
-        let timeline_path = self.conf.timeline_path(&tenant_shard_id, &timeline_id);
-        anyhow::ensure!(
-            !timeline_path.exists(),
-            "Timeline {timeline_path} already exists, cannot create its uninit mark file",
-        );
-
         let uninit_mark_path = self
             .conf
             .timeline_uninit_mark_file_path(tenant_shard_id, timeline_id);
+        let timeline_path = self.conf.timeline_path(&tenant_shard_id, &timeline_id);
+
+        let uninit_mark = TimelineUninitMark::new(
+            self,
+            timeline_id,
+            uninit_mark_path.clone(),
+            timeline_path.clone(),
+        )?;
+
+        // At this stage, we have got exclusive access to in-memory state for this timeline ID
+        // for creation.
+        // A timeline directory should never exist on disk already:
+        // - a previous failed creation would have cleaned up after itself
+        // - a pageserver restart would clean up timeline directories that don't have valid remote state
+        //
+        // Therefore it is an unexpected internal error to encounter a timeline directory already existing here,
+        // this error may indicate a bug in cleanup on failed creations.
+        if timeline_path.exists() {
+            return Err(TimelineExclusionError::Other(anyhow::anyhow!(
+                "Timeline directory already exists! This is a bug."
+            )));
+        }
+
+        // Create the on-disk uninit mark _after_ the in-memory acquisition of the tenant ID: guarantees
+        // that during process runtime, colliding creations will be caught in-memory without getting
+        // as far as failing to write a file.
         fs::OpenOptions::new()
             .write(true)
             .create_new(true)
@@ -3273,8 +3345,6 @@ impl Tenant {
                 format!("Failed to crate uninit mark for timeline {tenant_shard_id}/{timeline_id}")
             })?;
 
-        let uninit_mark = TimelineUninitMark::new(uninit_mark_path, timeline_path);
-
         Ok(uninit_mark)
     }
 
@@ -3717,6 +3787,7 @@ pub(crate) mod harness {
                     tenant_conf.evictions_low_residence_duration_metric_threshold,
                 ),
                 gc_feedback: Some(tenant_conf.gc_feedback),
+                heatmap_period: Some(tenant_conf.heatmap_period),
             }
         }
     }
@@ -4023,13 +4094,7 @@ mod tests {
             .await
         {
             Ok(_) => panic!("duplicate timeline creation should fail"),
-            Err(e) => assert_eq!(
-                e.to_string(),
-                format!(
-                    "Timeline {}/{} already exists in pageserver's memory",
-                    tenant.tenant_shard_id, TIMELINE_ID
-                )
-            ),
+            Err(e) => assert_eq!(e.to_string(), "Already exists".to_string()),
         }
 
         Ok(())

pageserver/src/tenant/config.rs

@@ -334,6 +334,11 @@ pub struct TenantConf {
     #[serde(with = "humantime_serde")]
     pub evictions_low_residence_duration_metric_threshold: Duration,
     pub gc_feedback: bool,
+
+    /// If non-zero, the period between uploads of a heatmap from attached tenants.  This
+    /// may be disabled if a Tenant will not have secondary locations: only secondary
+    /// locations will use the heatmap uploaded by attached locations.
+    pub heatmap_period: Duration,
 }
 
 /// Same as TenantConf, but this struct preserves the information about
@@ -414,6 +419,11 @@ pub struct TenantConfOpt {
     #[serde(skip_serializing_if = "Option::is_none")]
     #[serde(default)]
     pub gc_feedback: Option<bool>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(with = "humantime_serde")]
+    #[serde(default)]
+    pub heatmap_period: Option<Duration>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
@@ -482,6 +492,7 @@ impl TenantConfOpt {
                 .evictions_low_residence_duration_metric_threshold
                 .unwrap_or(global_conf.evictions_low_residence_duration_metric_threshold),
             gc_feedback: self.gc_feedback.unwrap_or(global_conf.gc_feedback),
+            heatmap_period: self.heatmap_period.unwrap_or(global_conf.heatmap_period),
         }
     }
 }
@@ -519,6 +530,7 @@ impl Default for TenantConf {
             )
             .expect("cannot parse default evictions_low_residence_duration_metric_threshold"),
             gc_feedback: false,
+            heatmap_period: Duration::ZERO,
         }
     }
 }

pageserver/src/tenant/delete.rs

@@ -460,12 +460,6 @@ impl DeleteTenantFlow {
     ) {
         let tenant_shard_id = tenant.tenant_shard_id;
 
-        let cancel = crate::PAGESERVER_SHUTDOWN_TOKEN
-            .get()
-            .cloned()
-            .unwrap_or_default()
-            .child_token();
-
         task_mgr::spawn(
             task_mgr::BACKGROUND_RUNTIME.handle(),
             TaskKind::TimelineDeletionWorker,
@@ -473,7 +467,6 @@ impl DeleteTenantFlow {
             None,
             "tenant_delete",
             false,
-            cancel,
             async move {
                 if let Err(err) =
                     Self::background(guard, conf, remote_storage, tenants, &tenant).await

pageserver/src/tenant/mgr.rs

@@ -283,7 +283,7 @@ async fn init_load_generations(
             "Emergency mode!  Tenants will be attached unsafely using their last known generation"
         );
         emergency_generations(tenant_confs)
-    } else if let Some(client) = ControlPlaneClient::new(conf, cancel.child_token()) {
+    } else if let Some(client) = ControlPlaneClient::new(conf, cancel) {
         info!("Calling control plane API to re-attach tenants");
         // If we are configured to use the control plane API, then it is the source of truth for what tenants to load.
         match client.re_attach().await {
@@ -807,6 +807,12 @@ pub(crate) async fn set_new_tenant_config(
 }
 
 impl TenantManager {
+    /// Convenience function so that anyone with a TenantManager can get at the global configuration, without
+    /// having to pass it around everywhere as a separate object.
+    pub(crate) fn get_conf(&self) -> &'static PageServerConf {
+        self.conf
+    }
+
     /// Gets the attached tenant from the in-memory data, erroring if it's absent, in secondary mode, or is not fitting to the query.
     /// `active_only = true` allows to query only tenants that are ready for operations, erroring on other kinds of tenants.
     pub(crate) fn get_attached_tenant_shard(
@@ -1087,6 +1093,20 @@ impl TenantManager {
 
         Ok(())
     }
+
+    pub(crate) fn get_attached_active_tenant_shards(&self) -> Vec<Arc<Tenant>> {
+        let locked = self.tenants.read().unwrap();
+        match &*locked {
+            TenantsMap::Initializing => Vec::new(),
+            TenantsMap::Open(map) | TenantsMap::ShuttingDown(map) => map
+                .values()
+                .filter_map(|slot| {
+                    slot.get_attached()
+                        .and_then(|t| if t.is_active() { Some(t.clone()) } else { None })
+                })
+                .collect(),
+        }
+    }
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -1352,11 +1372,6 @@ pub(crate) async fn detach_tenant(
     // 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;
-    let cancel = crate::PAGESERVER_SHUTDOWN_TOKEN
-        .get()
-        .cloned()
-        .unwrap_or_default()
-        .child_token();
     task_mgr::spawn(
         task_mgr::BACKGROUND_RUNTIME.handle(),
         TaskKind::MgmtRequest,
@@ -1364,7 +1379,6 @@ pub(crate) async fn detach_tenant(
         None,
         "tenant_files_delete",
         false,
-        cancel,
         async move {
             fs::remove_dir_all(tmp_path.as_path())
                 .await
@@ -2092,7 +2106,6 @@ pub(crate) async fn immediate_gc(
         Some(timeline_id),
         &format!("timeline_gc_handler garbage collection run for tenant {tenant_shard_id} timeline {timeline_id}"),
         false,
-        tenant.cancel.child_token(),
         async move {
             fail::fail_point!("immediate_gc_task_pre");
 

pageserver/src/tenant/remote_timeline_client.rs

@@ -180,7 +180,7 @@
 //! [`Tenant::timeline_init_and_sync`]: super::Tenant::timeline_init_and_sync
 //! [`Timeline::load_layer_map`]: super::Timeline::load_layer_map
 
-mod download;
+pub(crate) mod download;
 pub mod index;
 mod upload;
 
@@ -357,13 +357,9 @@ impl RemoteTimelineClient {
     /// Initialize the upload queue for a remote storage that already received
     /// an index file upload, i.e., it's not empty.
     /// The given `index_part` must be the one on the remote.
-    pub fn init_upload_queue(
-        &self,
-        index_part: &IndexPart,
-        cancel: CancellationToken,
-    ) -> anyhow::Result<()> {
+    pub fn init_upload_queue(&self, index_part: &IndexPart) -> anyhow::Result<()> {
         let mut upload_queue = self.upload_queue.lock().unwrap();
-        upload_queue.initialize_with_current_remote_index_part(index_part, cancel)?;
+        upload_queue.initialize_with_current_remote_index_part(index_part)?;
         self.update_remote_physical_size_gauge(Some(index_part));
         info!(
             "initialized upload queue from remote index with {} layer files",
@@ -377,10 +373,9 @@ impl RemoteTimelineClient {
     pub fn init_upload_queue_for_empty_remote(
         &self,
         local_metadata: &TimelineMetadata,
-        cancel: CancellationToken,
     ) -> anyhow::Result<()> {
         let mut upload_queue = self.upload_queue.lock().unwrap();
-        upload_queue.initialize_empty_remote(local_metadata, cancel)?;
+        upload_queue.initialize_empty_remote(local_metadata)?;
         self.update_remote_physical_size_gauge(None);
         info!("initialized upload queue as empty");
         Ok(())
@@ -391,7 +386,6 @@ impl RemoteTimelineClient {
     pub fn init_upload_queue_stopped_to_continue_deletion(
         &self,
         index_part: &IndexPart,
-        cancel: CancellationToken,
     ) -> anyhow::Result<()> {
         // FIXME: consider newtype for DeletedIndexPart.
         let deleted_at = index_part.deleted_at.ok_or(anyhow::anyhow!(
@@ -400,7 +394,7 @@ impl RemoteTimelineClient {
 
         {
             let mut upload_queue = self.upload_queue.lock().unwrap();
-            upload_queue.initialize_with_current_remote_index_part(index_part, cancel)?;
+            upload_queue.initialize_with_current_remote_index_part(index_part)?;
             self.update_remote_physical_size_gauge(Some(index_part));
         }
         // also locks upload queue, without dropping the guard above it will be a deadlock
@@ -1233,7 +1227,6 @@ impl RemoteTimelineClient {
                 Some(self.timeline_id),
                 "remote upload",
                 false,
-                upload_queue.cancel.child_token(),
                 async move {
                     self_rc.perform_upload_task(task).await;
                     Ok(())
@@ -1568,13 +1561,6 @@ impl RemoteTimelineClient {
                         dangling_files: HashMap::default(),
                         shutting_down: false,
                         shutdown_ready: Arc::new(tokio::sync::Semaphore::new(0)),
-                        // TODO: this is the only place where we cannot reasonably continue the
-                        // tree
-                        cancel: crate::PAGESERVER_SHUTDOWN_TOKEN
-                            .get()
-                            .cloned()
-                            .unwrap_or_default()
-                            .child_token(),
                     };
 
                     let upload_queue = std::mem::replace(
@@ -1618,6 +1604,23 @@ impl RemoteTimelineClient {
             }
         }
     }
+
+    pub(crate) fn get_layers_metadata(
+        &self,
+        layers: Vec<LayerFileName>,
+    ) -> anyhow::Result<Vec<Option<LayerFileMetadata>>> {
+        let q = self.upload_queue.lock().unwrap();
+        let q = match &*q {
+            UploadQueue::Stopped(_) | UploadQueue::Uninitialized => {
+                anyhow::bail!("queue is in state {}", q.as_str())
+            }
+            UploadQueue::Initialized(inner) => inner,
+        };
+
+        let decorated = layers.into_iter().map(|l| q.latest_files.get(&l).cloned());
+
+        Ok(decorated.collect())
+    }
 }
 
 pub fn remote_timelines_path(tenant_shard_id: &TenantShardId) -> RemotePath {
@@ -1673,6 +1676,13 @@ pub fn remote_index_path(
     .expect("Failed to construct path")
 }
 
+pub const HEATMAP_BASENAME: &str = "heatmap-v1.json";
+
+pub(crate) fn remote_heatmap_path(tenant_shard_id: &TenantShardId) -> RemotePath {
+    RemotePath::from_string(&format!("tenants/{tenant_shard_id}/{HEATMAP_BASENAME}"))
+        .expect("Failed to construct path")
+}
+
 /// Given the key of an index, parse out the generation part of the name
 pub fn parse_remote_index_path(path: RemotePath) -> Option<Generation> {
     let file_name = match path.get_path().file_name() {

pageserver/src/tenant/remote_timeline_client/upload.rs

@@ -4,8 +4,9 @@ use anyhow::{bail, Context};
 use camino::Utf8Path;
 use fail::fail_point;
 use pageserver_api::shard::TenantShardId;
-use std::io::ErrorKind;
+use std::io::{ErrorKind, SeekFrom};
 use tokio::fs::{self, File};
+use tokio::io::AsyncSeekExt;
 
 use super::Generation;
 use crate::{
@@ -119,11 +120,14 @@ pub(crate) async fn upload_initdb_dir(
     storage: &GenericRemoteStorage,
     tenant_id: &TenantId,
     timeline_id: &TimelineId,
-    initdb_tar_zst: File,
+    mut initdb_tar_zst: File,
     size: u64,
 ) -> anyhow::Result<()> {
     tracing::trace!("uploading initdb dir");
 
+    // We might have read somewhat into the file already in the prior retry attempt
+    initdb_tar_zst.seek(SeekFrom::Start(0)).await?;
+
     let file = tokio_util::io::ReaderStream::with_capacity(initdb_tar_zst, super::BUFFER_SIZE);
 
     let remote_path = remote_initdb_archive_path(tenant_id, timeline_id);

pageserver/src/tenant/secondary.rs

@@ -0,0 +1,104 @@
+pub mod heatmap;
+mod heatmap_uploader;
+
+use std::sync::Arc;
+
+use crate::task_mgr::{self, TaskKind, BACKGROUND_RUNTIME};
+
+use self::heatmap_uploader::heatmap_uploader_task;
+
+use super::mgr::TenantManager;
+
+use pageserver_api::shard::TenantShardId;
+use remote_storage::GenericRemoteStorage;
+
+use tokio_util::sync::CancellationToken;
+use utils::completion::Barrier;
+
+enum UploadCommand {
+    Upload(TenantShardId),
+}
+
+struct CommandRequest<T> {
+    payload: T,
+    response_tx: tokio::sync::oneshot::Sender<CommandResponse>,
+}
+
+struct CommandResponse {
+    result: anyhow::Result<()>,
+}
+
+/// The SecondaryController is a pseudo-rpc client for administrative control of secondary mode downloads,
+/// and heatmap uploads.  This is not a hot data path: it's primarily a hook for tests,
+/// where we want to immediately upload/download for a particular tenant.  In normal operation
+/// uploads & downloads are autonomous and not driven by this interface.
+pub struct SecondaryController {
+    upload_req_tx: tokio::sync::mpsc::Sender<CommandRequest<UploadCommand>>,
+}
+
+impl SecondaryController {
+    async fn dispatch<T>(
+        &self,
+        queue: &tokio::sync::mpsc::Sender<CommandRequest<T>>,
+        payload: T,
+    ) -> anyhow::Result<()> {
+        let (response_tx, response_rx) = tokio::sync::oneshot::channel();
+
+        queue
+            .send(CommandRequest {
+                payload,
+                response_tx,
+            })
+            .await
+            .map_err(|_| anyhow::anyhow!("Receiver shut down"))?;
+
+        let response = response_rx
+            .await
+            .map_err(|_| anyhow::anyhow!("Request dropped"))?;
+
+        response.result
+    }
+
+    pub async fn upload_tenant(&self, tenant_shard_id: TenantShardId) -> anyhow::Result<()> {
+        self.dispatch(&self.upload_req_tx, UploadCommand::Upload(tenant_shard_id))
+            .await
+    }
+}
+
+pub fn spawn_tasks(
+    tenant_manager: Arc<TenantManager>,
+    remote_storage: GenericRemoteStorage,
+    background_jobs_can_start: Barrier,
+    cancel: CancellationToken,
+) -> SecondaryController {
+    let (upload_req_tx, upload_req_rx) =
+        tokio::sync::mpsc::channel::<CommandRequest<UploadCommand>>(16);
+
+    task_mgr::spawn(
+        BACKGROUND_RUNTIME.handle(),
+        TaskKind::SecondaryUploads,
+        None,
+        None,
+        "heatmap uploads",
+        false,
+        async move {
+            heatmap_uploader_task(
+                tenant_manager,
+                remote_storage,
+                upload_req_rx,
+                background_jobs_can_start,
+                cancel,
+            )
+            .await
+        },
+    );
+
+    SecondaryController { upload_req_tx }
+}
+
+/// For running with remote storage disabled: a SecondaryController that is connected to nothing.
+pub fn null_controller() -> SecondaryController {
+    let (upload_req_tx, _upload_req_rx) =
+        tokio::sync::mpsc::channel::<CommandRequest<UploadCommand>>(16);
+    SecondaryController { upload_req_tx }
+}

pageserver/src/tenant/secondary/heatmap.rs

@@ -0,0 +1,64 @@
+use std::time::SystemTime;
+
+use crate::tenant::{
+    remote_timeline_client::index::IndexLayerMetadata, storage_layer::LayerFileName,
+};
+
+use serde::{Deserialize, Serialize};
+use serde_with::{serde_as, DisplayFromStr, TimestampSeconds};
+
+use utils::{generation::Generation, id::TimelineId};
+
+#[derive(Serialize, Deserialize)]
+pub(super) struct HeatMapTenant {
+    /// Generation of the attached location that uploaded the heatmap: this is not required
+    /// for correctness, but acts as a hint to secondary locations in order to detect thrashing
+    /// in the unlikely event that two attached locations are both uploading conflicting heatmaps.
+    pub(super) generation: Generation,
+
+    pub(super) timelines: Vec<HeatMapTimeline>,
+}
+
+#[serde_as]
+#[derive(Serialize, Deserialize)]
+pub(crate) struct HeatMapTimeline {
+    #[serde_as(as = "DisplayFromStr")]
+    pub(super) timeline_id: TimelineId,
+
+    pub(super) layers: Vec<HeatMapLayer>,
+}
+
+#[serde_as]
+#[derive(Serialize, Deserialize)]
+pub(crate) struct HeatMapLayer {
+    pub(super) name: LayerFileName,
+    pub(super) metadata: IndexLayerMetadata,
+
+    #[serde_as(as = "TimestampSeconds<i64>")]
+    pub(super) access_time: SystemTime,
+    // TODO: an actual 'heat' score that would let secondary locations prioritize downloading
+    // the hottest layers, rather than trying to simply mirror whatever layers are on-disk on the primary.
+}
+
+impl HeatMapLayer {
+    pub(crate) fn new(
+        name: LayerFileName,
+        metadata: IndexLayerMetadata,
+        access_time: SystemTime,
+    ) -> Self {
+        Self {
+            name,
+            metadata,
+            access_time,
+        }
+    }
+}
+
+impl HeatMapTimeline {
+    pub(crate) fn new(timeline_id: TimelineId, layers: Vec<HeatMapLayer>) -> Self {
+        Self {
+            timeline_id,
+            layers,
+        }
+    }
+}

pageserver/src/tenant/secondary/heatmap_uploader.rs

@@ -0,0 +1,582 @@
+use std::{
+    collections::HashMap,
+    sync::{Arc, Weak},
+    time::{Duration, Instant},
+};
+
+use crate::{
+    metrics::SECONDARY_MODE,
+    tenant::{
+        config::AttachmentMode, mgr::TenantManager, remote_timeline_client::remote_heatmap_path,
+        secondary::CommandResponse, span::debug_assert_current_span_has_tenant_id, Tenant,
+    },
+};
+
+use md5;
+use pageserver_api::shard::TenantShardId;
+use remote_storage::GenericRemoteStorage;
+
+use tokio::task::JoinSet;
+use tokio_util::sync::CancellationToken;
+use tracing::instrument;
+use utils::{backoff, completion::Barrier};
+
+use super::{heatmap::HeatMapTenant, CommandRequest, UploadCommand};
+
+/// Period between heatmap uploader walking Tenants to look for work to do.
+/// If any tenants have a heatmap upload period lower than this, it will be adjusted
+/// downward to match.
+const DEFAULT_SCHEDULING_INTERVAL: Duration = Duration::from_millis(60000);
+const MIN_SCHEDULING_INTERVAL: Duration = Duration::from_millis(1000);
+
+struct WriteInProgress {
+    barrier: Barrier,
+}
+
+struct UploadPending {
+    tenant: Arc<Tenant>,
+    last_digest: Option<md5::Digest>,
+}
+
+struct WriteComplete {
+    tenant_shard_id: TenantShardId,
+    completed_at: Instant,
+    digest: Option<md5::Digest>,
+    next_upload: Option<Instant>,
+}
+
+/// The heatmap uploader keeps a little bit of per-tenant state, mainly to remember
+/// when we last did a write.  We only populate this after doing at least one
+/// write for a tenant -- this avoids holding state for tenants that have
+/// uploads disabled.
+
+struct UploaderTenantState {
+    // This Weak only exists to enable culling idle instances of this type
+    // when the Tenant has been deallocated.
+    tenant: Weak<Tenant>,
+
+    /// Digest of the serialized heatmap that we last successfully uploaded
+    ///
+    /// md5 is generally a bad hash.  We use it because it's convenient for interop with AWS S3's ETag,
+    /// which is also an md5sum.
+    last_digest: Option<md5::Digest>,
+
+    /// When the last upload attempt completed (may have been successful or failed)
+    last_upload: Option<Instant>,
+
+    /// When should we next do an upload?  None means never.
+    next_upload: Option<Instant>,
+}
+
+/// This type is owned by a single task ([`heatmap_uploader_task`]) which runs an event
+/// handling loop and mutates it as needed: there are no locks here, because that event loop
+/// can hold &mut references to this type throughout.
+struct HeatmapUploader {
+    tenant_manager: Arc<TenantManager>,
+    remote_storage: GenericRemoteStorage,
+    cancel: CancellationToken,
+
+    tenants: HashMap<TenantShardId, UploaderTenantState>,
+
+    /// Tenants with work to do, for which tasks should be spawned as soon as concurrency
+    /// limits permit it.
+    tenants_pending: std::collections::VecDeque<UploadPending>,
+
+    /// Tenants for which a task in `tasks` has been spawned.
+    tenants_uploading: HashMap<TenantShardId, WriteInProgress>,
+
+    tasks: JoinSet<()>,
+
+    /// Channel for our child tasks to send results to: we use a channel for results rather than
+    /// just getting task results via JoinSet because we need the channel's recv() "sleep until something
+    /// is available" semantic, rather than JoinSet::join_next()'s "sleep until next thing is available _or_ I'm empty"
+    /// behavior.
+    task_result_tx: tokio::sync::mpsc::UnboundedSender<WriteComplete>,
+    task_result_rx: tokio::sync::mpsc::UnboundedReceiver<WriteComplete>,
+
+    concurrent_uploads: usize,
+
+    scheduling_interval: Duration,
+}
+
+/// The uploader task runs a loop that periodically wakes up and schedules tasks for
+/// tenants that require an upload, or handles any commands that have been sent into
+/// `command_queue`.  No I/O is done in this loop: that all happens in the tasks we
+/// spawn.
+///
+/// Scheduling iterations are somewhat infrequent.  However, each one will enqueue
+/// all tenants that require an upload, and in between scheduling iterations we will
+/// continue to spawn new tasks for pending tenants, as our concurrency limit permits.
+///
+/// While we take a CancellationToken here, it is subordinate to the CancellationTokens
+/// of tenants: i.e. we expect all Tenants to have been shut down before we are shut down, otherwise
+/// we might block waiting on a Tenant.
+pub(super) async fn heatmap_uploader_task(
+    tenant_manager: Arc<TenantManager>,
+    remote_storage: GenericRemoteStorage,
+    mut command_queue: tokio::sync::mpsc::Receiver<CommandRequest<UploadCommand>>,
+    background_jobs_can_start: Barrier,
+    cancel: CancellationToken,
+) -> anyhow::Result<()> {
+    let concurrent_uploads = tenant_manager.get_conf().heatmap_upload_concurrency;
+
+    let (result_tx, result_rx) = tokio::sync::mpsc::unbounded_channel();
+
+    let mut uploader = HeatmapUploader {
+        tenant_manager,
+        remote_storage,
+        cancel: cancel.clone(),
+        tasks: JoinSet::new(),
+        tenants: HashMap::new(),
+        tenants_pending: std::collections::VecDeque::new(),
+        tenants_uploading: HashMap::new(),
+        task_result_tx: result_tx,
+        task_result_rx: result_rx,
+        concurrent_uploads,
+        scheduling_interval: DEFAULT_SCHEDULING_INTERVAL,
+    };
+
+    tracing::info!("Waiting for background_jobs_can start...");
+    background_jobs_can_start.wait().await;
+    tracing::info!("background_jobs_can is ready, proceeding.");
+
+    while !cancel.is_cancelled() {
+        // Look for new work: this is relatively expensive because we have to go acquire the lock on
+        // the tenant manager to retrieve tenants, and then iterate over them to figure out which ones
+        // require an upload.
+        uploader.schedule_iteration().await?;
+
+        // Between scheduling iterations, we will:
+        //  - Drain any complete tasks and spawn pending tasks
+        //  - Handle incoming administrative commands
+        //  - Check our cancellation token
+        let next_scheduling_iteration = Instant::now()
+            .checked_add(uploader.scheduling_interval)
+            .unwrap_or_else(|| {
+                tracing::warn!(
+                    "Scheduling interval invalid ({}s), running immediately!",
+                    uploader.scheduling_interval.as_secs_f64()
+                );
+                Instant::now()
+            });
+        loop {
+            tokio::select! {
+                _ = cancel.cancelled() => {
+                    // We do not simply drop the JoinSet, in order to have an orderly shutdown without cancellation.
+                    tracing::info!("Heatmap uploader joining tasks");
+                    while let Some(_r) = uploader.tasks.join_next().await {};
+                    tracing::info!("Heatmap uploader terminating");
+
+                    break;
+                },
+                _ = tokio::time::sleep(next_scheduling_iteration.duration_since(Instant::now())) => {
+                    tracing::debug!("heatmap_uploader_task: woke for scheduling interval");
+                    break;},
+                cmd = command_queue.recv() => {
+                    tracing::debug!("heatmap_uploader_task: woke for command queue");
+                    let cmd = match cmd {
+                        Some(c) =>c,
+                        None => {
+                            // SecondaryController was destroyed, and this has raced with
+                            // our CancellationToken
+                            tracing::info!("Heatmap uploader terminating");
+                            cancel.cancel();
+                            break;
+                        }
+                    };
+
+                    let CommandRequest{
+                        response_tx,
+                        payload
+                    } = cmd;
+                    uploader.handle_command(payload, response_tx);
+                },
+                _ = uploader.process_next_completion() => {
+                    if !cancel.is_cancelled() {
+                        uploader.spawn_pending();
+                    }
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+impl HeatmapUploader {
+    /// Periodic execution phase: inspect all attached tenants and schedule any work they require.
+    async fn schedule_iteration(&mut self) -> anyhow::Result<()> {
+        // Cull any entries in self.tenants whose Arc<Tenant> is gone
+        self.tenants
+            .retain(|_k, v| v.tenant.upgrade().is_some() && v.next_upload.is_some());
+
+        // The priority order of previously scheduled work may be invalidated by current state: drop
+        // all pending work (it will be re-scheduled if still needed)
+        self.tenants_pending.clear();
+
+        // Used a fixed 'now' through the following loop, for efficiency and fairness.
+        let now = Instant::now();
+
+        // While iterating over the potentially-long list of tenants, we will periodically yield
+        // to avoid blocking executor.
+        const YIELD_ITERATIONS: usize = 1000;
+
+        // Iterate over tenants looking for work to do.
+        let tenants = self.tenant_manager.get_attached_active_tenant_shards();
+        for (i, tenant) in tenants.into_iter().enumerate() {
+            // Process is shutting down, drop out
+            if self.cancel.is_cancelled() {
+                return Ok(());
+            }
+
+            // Skip tenants that already have a write in flight
+            if self
+                .tenants_uploading
+                .contains_key(tenant.get_tenant_shard_id())
+            {
+                continue;
+            }
+
+            self.maybe_schedule_upload(&now, tenant);
+
+            if i + 1 % YIELD_ITERATIONS == 0 {
+                tokio::task::yield_now().await;
+            }
+        }
+
+        // Spawn tasks for as many of our pending tenants as we can.
+        self.spawn_pending();
+
+        Ok(())
+    }
+
+    ///
+    /// Cancellation: this method is cancel-safe.
+    async fn process_next_completion(&mut self) {
+        match self.task_result_rx.recv().await {
+            Some(r) => {
+                self.on_completion(r);
+            }
+            None => {
+                unreachable!("Result sender is stored on Self");
+            }
+        }
+    }
+
+    /// The 'maybe' refers to the tenant's state: whether it is configured
+    /// for heatmap uploads at all, and whether sufficient time has passed
+    /// since the last upload.
+    fn maybe_schedule_upload(&mut self, now: &Instant, tenant: Arc<Tenant>) {
+        match tenant.get_heatmap_period() {
+            None => {
+                // Heatmaps are disabled for this tenant
+                return;
+            }
+            Some(period) => {
+                // If any tenant has asked for uploads more frequent than our scheduling interval,
+                // reduce it to match so that we can keep up.  This is mainly useful in testing, where
+                // we may set rather short intervals.
+                if period < self.scheduling_interval {
+                    self.scheduling_interval = std::cmp::max(period, MIN_SCHEDULING_INTERVAL);
+                }
+            }
+        }
+
+        // Stale attachments do not upload anything: if we are in this state, there is probably some
+        // other attachment in mode Single or Multi running on another pageserver, and we don't
+        // want to thrash and overwrite their heatmap uploads.
+        if tenant.get_attach_mode() == AttachmentMode::Stale {
+            return;
+        }
+
+        // Create an entry in self.tenants if one doesn't already exist: this will later be updated
+        // with the completion time in on_completion.
+        let state = self
+            .tenants
+            .entry(*tenant.get_tenant_shard_id())
+            .or_insert_with(|| UploaderTenantState {
+                tenant: Arc::downgrade(&tenant),
+                last_upload: None,
+                next_upload: Some(Instant::now()),
+                last_digest: None,
+            });
+
+        // Decline to do the upload if insufficient time has passed
+        if state.next_upload.map(|nu| &nu > now).unwrap_or(false) {
+            return;
+        }
+
+        let last_digest = state.last_digest;
+        self.tenants_pending.push_back(UploadPending {
+            tenant,
+            last_digest,
+        })
+    }
+
+    fn spawn_pending(&mut self) {
+        while !self.tenants_pending.is_empty()
+            && self.tenants_uploading.len() < self.concurrent_uploads
+        {
+            // unwrap: loop condition includes !is_empty()
+            let pending = self.tenants_pending.pop_front().unwrap();
+            self.spawn_upload(pending.tenant, pending.last_digest);
+        }
+    }
+
+    fn spawn_upload(&mut self, tenant: Arc<Tenant>, last_digest: Option<md5::Digest>) {
+        let remote_storage = self.remote_storage.clone();
+        let tenant_shard_id = *tenant.get_tenant_shard_id();
+        let (completion, barrier) = utils::completion::channel();
+        let result_tx = self.task_result_tx.clone();
+        self.tasks.spawn(async move {
+            // Guard for the barrier in [`WriteInProgress`]
+            let _completion = completion;
+
+            let started_at = Instant::now();
+            let digest = match upload_tenant_heatmap(remote_storage, &tenant, last_digest).await {
+                Ok(UploadHeatmapOutcome::Uploaded(digest)) => {
+                    let duration = Instant::now().duration_since(started_at);
+                    SECONDARY_MODE
+                        .upload_heatmap_duration
+                        .observe(duration.as_secs_f64());
+                    SECONDARY_MODE.upload_heatmap.inc();
+                    Some(digest)
+                }
+                Ok(UploadHeatmapOutcome::NoChange | UploadHeatmapOutcome::Skipped) => last_digest,
+                Err(UploadHeatmapError::Upload(e)) => {
+                    tracing::warn!(
+                        "Failed to upload heatmap for tenant {}: {e:#}",
+                        tenant.get_tenant_shard_id(),
+                    );
+                    let duration = Instant::now().duration_since(started_at);
+                    SECONDARY_MODE
+                        .upload_heatmap_duration
+                        .observe(duration.as_secs_f64());
+                    SECONDARY_MODE.upload_heatmap_errors.inc();
+                    last_digest
+                }
+                Err(UploadHeatmapError::Cancelled) => {
+                    tracing::info!("Cancelled heatmap upload, shutting down");
+                    last_digest
+                }
+            };
+
+            let now = Instant::now();
+            let next_upload = tenant
+                .get_heatmap_period()
+                .and_then(|period| now.checked_add(period));
+
+            result_tx
+                .send(WriteComplete {
+                    tenant_shard_id: *tenant.get_tenant_shard_id(),
+                    completed_at: now,
+                    digest,
+                    next_upload,
+                })
+                .ok();
+        });
+
+        self.tenants_uploading
+            .insert(tenant_shard_id, WriteInProgress { barrier });
+    }
+
+    #[instrument(skip_all, fields(tenant_id=%completion.tenant_shard_id.tenant_id, shard_id=%completion.tenant_shard_id.shard_slug()))]
+    fn on_completion(&mut self, completion: WriteComplete) {
+        tracing::debug!("Heatmap upload completed");
+        let WriteComplete {
+            tenant_shard_id,
+            completed_at,
+            digest,
+            next_upload,
+        } = completion;
+        self.tenants_uploading.remove(&tenant_shard_id);
+        use std::collections::hash_map::Entry;
+        match self.tenants.entry(tenant_shard_id) {
+            Entry::Vacant(_) => {
+                // Tenant state was dropped, nothing to update.
+            }
+            Entry::Occupied(mut entry) => {
+                entry.get_mut().last_upload = Some(completed_at);
+                entry.get_mut().last_digest = digest;
+                entry.get_mut().next_upload = next_upload
+            }
+        }
+    }
+
+    fn handle_command(
+        &mut self,
+        command: UploadCommand,
+        response_tx: tokio::sync::oneshot::Sender<CommandResponse>,
+    ) {
+        match command {
+            UploadCommand::Upload(tenant_shard_id) => {
+                // If an upload was ongoing for this tenant, let it finish first.
+                let barrier = if let Some(writing_state) =
+                    self.tenants_uploading.get(&tenant_shard_id)
+                {
+                    tracing::info!(
+                        tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(),
+                        "Waiting for heatmap write to complete");
+                    writing_state.barrier.clone()
+                } else {
+                    // Spawn the upload then immediately wait for it.  This will block processing of other commands and
+                    // starting of other background work.
+                    tracing::info!(
+                        tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(),
+                        "Starting heatmap write on command");
+                    let tenant = match self
+                        .tenant_manager
+                        .get_attached_tenant_shard(tenant_shard_id, true)
+                    {
+                        Ok(t) => t,
+                        Err(e) => {
+                            // Drop result of send: we don't care if caller dropped their receiver
+                            drop(response_tx.send(CommandResponse {
+                                result: Err(e.into()),
+                            }));
+                            return;
+                        }
+                    };
+                    self.spawn_upload(tenant, None);
+                    let writing_state = self
+                        .tenants_uploading
+                        .get(&tenant_shard_id)
+                        .expect("We just inserted this");
+                    tracing::info!(
+                        tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(),
+                        "Waiting for heatmap upload to complete");
+
+                    writing_state.barrier.clone()
+                };
+
+                // This task does no I/O: it only listens for a barrier's completion and then
+                // sends to the command response channel.  It is therefore safe to spawn this without
+                // any gates/task_mgr hooks.
+                tokio::task::spawn(async move {
+                    barrier.wait().await;
+
+                    tracing::info!(
+                        tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(),
+                        "Heatmap upload complete");
+
+                    // Drop result of send: we don't care if caller dropped their receiver
+                    drop(response_tx.send(CommandResponse { result: Ok(()) }))
+                });
+            }
+        }
+    }
+}
+
+enum UploadHeatmapOutcome {
+    /// We successfully wrote to remote storage, with this digest.
+    Uploaded(md5::Digest),
+    /// We did not upload because the heatmap digest was unchanged since the last upload
+    NoChange,
+    /// We skipped the upload for some reason, such as tenant/timeline not ready
+    Skipped,
+}
+
+#[derive(thiserror::Error, Debug)]
+enum UploadHeatmapError {
+    #[error("Cancelled")]
+    Cancelled,
+
+    #[error(transparent)]
+    Upload(#[from] anyhow::Error),
+}
+
+/// The inner upload operation.  This will skip if `last_digest` is Some and matches the digest
+/// of the object we would have uploaded.
+#[instrument(skip_all, fields(tenant_id = %tenant.get_tenant_shard_id().tenant_id, shard_id = %tenant.get_tenant_shard_id().shard_slug()))]
+async fn upload_tenant_heatmap(
+    remote_storage: GenericRemoteStorage,
+    tenant: &Arc<Tenant>,
+    last_digest: Option<md5::Digest>,
+) -> Result<UploadHeatmapOutcome, UploadHeatmapError> {
+    debug_assert_current_span_has_tenant_id();
+
+    let generation = tenant.get_generation();
+    if generation.is_none() {
+        // We do not expect this: generations were implemented before heatmap uploads.  However,
+        // handle it so that we don't have to make the generation in the heatmap an Option<>
+        // (Generation::none is not serializable)
+        tracing::warn!("Skipping heatmap upload for tenant with generation==None");
+        return Ok(UploadHeatmapOutcome::Skipped);
+    }
+
+    let mut heatmap = HeatMapTenant {
+        timelines: Vec::new(),
+        generation,
+    };
+    let timelines = tenant.timelines.lock().unwrap().clone();
+
+    let tenant_cancel = tenant.cancel.clone();
+
+    // Ensure that Tenant::shutdown waits for any upload in flight: this is needed because otherwise
+    // when we delete a tenant, we might race with an upload in flight and end up leaving a heatmap behind
+    // in remote storage.
+    let _guard = match tenant.gate.enter() {
+        Ok(g) => g,
+        Err(_) => {
+            tracing::info!("Skipping heatmap upload for tenant which is shutting down");
+            return Err(UploadHeatmapError::Cancelled);
+        }
+    };
+
+    for (timeline_id, timeline) in timelines {
+        let heatmap_timeline = timeline.generate_heatmap().await;
+        match heatmap_timeline {
+            None => {
+                tracing::debug!(
+                    "Skipping heatmap upload because timeline {timeline_id} is not ready"
+                );
+                return Ok(UploadHeatmapOutcome::Skipped);
+            }
+            Some(heatmap_timeline) => {
+                heatmap.timelines.push(heatmap_timeline);
+            }
+        }
+    }
+
+    // Serialize the heatmap
+    let bytes = serde_json::to_vec(&heatmap).map_err(|e| anyhow::anyhow!(e))?;
+    let size = bytes.len();
+
+    // Drop out early if nothing changed since our last upload
+    let digest = md5::compute(&bytes);
+    if Some(digest) == last_digest {
+        return Ok(UploadHeatmapOutcome::NoChange);
+    }
+
+    let path = remote_heatmap_path(tenant.get_tenant_shard_id());
+
+    // Write the heatmap.
+    tracing::debug!("Uploading {size} byte heatmap to {path}");
+    if let Err(e) = backoff::retry(
+        || async {
+            let bytes = futures::stream::once(futures::future::ready(Ok(bytes::Bytes::from(
+                bytes.clone(),
+            ))));
+            remote_storage
+                .upload_storage_object(bytes, size, &path)
+                .await
+        },
+        |_| false,
+        3,
+        u32::MAX,
+        "Uploading heatmap",
+        backoff::Cancel::new(tenant_cancel.clone(), || anyhow::anyhow!("Shutting down")),
+    )
+    .await
+    {
+        if tenant_cancel.is_cancelled() {
+            return Err(UploadHeatmapError::Cancelled);
+        } else {
+            return Err(e.into());
+        }
+    }
+
+    tracing::info!("Successfully uploaded {size} byte heatmap to {path}");
+
+    Ok(UploadHeatmapOutcome::Uploaded(digest))
+}

pageserver/src/tenant/storage_layer/layer.rs

@@ -457,6 +457,8 @@ struct LayerInner {
     /// For loaded layers, this may be some other value if the tenant has undergone
     /// a shard split since the layer was originally written.
     shard: ShardIndex,
+
+    last_evicted_at: std::sync::Mutex<Option<std::time::Instant>>,
 }
 
 impl std::fmt::Display for LayerInner {
@@ -587,6 +589,7 @@ impl LayerInner {
             consecutive_failures: AtomicUsize::new(0),
             generation,
             shard,
+            last_evicted_at: std::sync::Mutex::default(),
         }
     }
 
@@ -722,6 +725,14 @@ impl LayerInner {
                     permit
                 };
 
+                let since_last_eviction =
+                    self.last_evicted_at.lock().unwrap().map(|ts| ts.elapsed());
+                if let Some(since_last_eviction) = since_last_eviction {
+                    // FIXME: this will not always be recorded correctly until #6028 (the no
+                    // download needed branch above)
+                    LAYER_IMPL_METRICS.record_redownloaded_after(since_last_eviction);
+                }
+
                 let res = Arc::new(DownloadedLayer {
                     owner: Arc::downgrade(self),
                     kind: tokio::sync::OnceCell::default(),
@@ -841,7 +852,6 @@ impl LayerInner {
             Some(self.desc.timeline_id),
             &task_name,
             false,
-            timeline.cancel.child_token(),
             async move {
 
                 let client = timeline
@@ -861,21 +871,6 @@ impl LayerInner {
                         Ok(())
                     }
                     Err(e) => {
-                        let consecutive_failures =
-                            this.consecutive_failures.fetch_add(1, Ordering::Relaxed);
-
-                        let backoff = utils::backoff::exponential_backoff_duration_seconds(
-                            consecutive_failures.min(u32::MAX as usize) as u32,
-                            1.5,
-                            60.0,
-                        );
-                        let backoff = std::time::Duration::from_secs_f64(backoff);
-
-                        tokio::select! {
-                            _ = tokio::time::sleep(backoff) => {},
-                            _ = crate::task_mgr::shutdown_token().cancelled_owned() => {},
-                        };
-
                         Err(e)
                     }
                 };
@@ -923,7 +918,24 @@ impl LayerInner {
 
                 Ok(permit)
             }
-            Ok((Err(_), _permit)) => Err(DownloadError::DownloadFailed),
+            Ok((Err(e), _permit)) => {
+                // FIXME: this should be with the spawned task and be cancellation sensitive
+                //
+                // while we should not need this, this backoff has turned out to be useful with
+                // a bug of unexpectedly deleted remote layer file (#5787).
+                let consecutive_failures =
+                    self.consecutive_failures.fetch_add(1, Ordering::Relaxed);
+                tracing::error!(consecutive_failures, "layer file download failed: {e:#}");
+                let backoff = utils::backoff::exponential_backoff_duration_seconds(
+                    consecutive_failures.min(u32::MAX as usize) as u32,
+                    1.5,
+                    60.0,
+                );
+                let backoff = std::time::Duration::from_secs_f64(backoff);
+
+                tokio::time::sleep(backoff).await;
+                Err(DownloadError::DownloadFailed)
+            }
             Err(_gone) => Err(DownloadError::DownloadCancelled),
         }
     }
@@ -1116,6 +1128,8 @@ impl LayerInner {
         // we are still holding the permit, so no new spawn_download_and_wait can happen
         drop(self.status.send(Status::Evicted));
 
+        *self.last_evicted_at.lock().unwrap() = Some(std::time::Instant::now());
+
         res
     }
 
@@ -1420,6 +1434,7 @@ pub(crate) struct LayerImplMetrics {
 
     rare_counters: enum_map::EnumMap<RareEvent, IntCounter>,
     inits_cancelled: metrics::core::GenericCounter<metrics::core::AtomicU64>,
+    redownload_after: metrics::Histogram,
 }
 
 impl Default for LayerImplMetrics {
@@ -1495,6 +1510,26 @@ impl Default for LayerImplMetrics {
         )
         .unwrap();
 
+        let redownload_after = {
+            let minute = 60.0;
+            let hour = 60.0 * minute;
+            metrics::register_histogram!(
+                "pageserver_layer_redownloaded_after",
+                "Time between evicting and re-downloading.",
+                vec![
+                    10.0,
+                    30.0,
+                    minute,
+                    5.0 * minute,
+                    15.0 * minute,
+                    30.0 * minute,
+                    hour,
+                    12.0 * hour,
+                ]
+            )
+            .unwrap()
+        };
+
         Self {
             started_evictions,
             completed_evictions,
@@ -1506,6 +1541,7 @@ impl Default for LayerImplMetrics {
 
             rare_counters,
             inits_cancelled,
+            redownload_after,
         }
     }
 }
@@ -1573,6 +1609,10 @@ impl LayerImplMetrics {
     fn inc_init_cancelled(&self) {
         self.inits_cancelled.inc()
     }
+
+    fn record_redownloaded_after(&self, duration: std::time::Duration) {
+        self.redownload_after.observe(duration.as_secs_f64())
+    }
 }
 
 #[derive(enum_map::Enum)]

pageserver/src/tenant/tasks.rs

@@ -54,17 +54,14 @@ impl BackgroundLoopKind {
     }
 }
 
+/// Cancellation safe.
 pub(crate) async fn concurrent_background_tasks_rate_limit_permit(
     loop_kind: BackgroundLoopKind,
     _ctx: &RequestContext,
 ) -> impl Drop {
-    crate::metrics::BACKGROUND_LOOP_SEMAPHORE_WAIT_START_COUNT
+    let _guard = crate::metrics::BACKGROUND_LOOP_SEMAPHORE_WAIT_GAUGE
         .with_label_values(&[loop_kind.as_static_str()])
-        .inc();
-
-    scopeguard::defer!(
-        crate::metrics::BACKGROUND_LOOP_SEMAPHORE_WAIT_FINISH_COUNT.with_label_values(&[loop_kind.as_static_str()]).inc();
-    );
+        .guard();
 
     match CONCURRENT_BACKGROUND_TASKS.acquire().await {
         Ok(permit) => permit,
@@ -85,7 +82,6 @@ pub fn start_background_loops(
         None,
         &format!("compactor for tenant {tenant_shard_id}"),
         false,
-        tenant.cancel.child_token(),
         {
             let tenant = Arc::clone(tenant);
             let background_jobs_can_start = background_jobs_can_start.cloned();
@@ -109,7 +105,6 @@ pub fn start_background_loops(
         None,
         &format!("garbage collector for tenant {tenant_shard_id}"),
         false,
-        tenant.cancel.child_token(),
         {
             let tenant = Arc::clone(tenant);
             let background_jobs_can_start = background_jobs_can_start.cloned();

pageserver/src/tenant/timeline.rs

@@ -98,8 +98,9 @@ use self::logical_size::LogicalSize;
 use self::walreceiver::{WalReceiver, WalReceiverConf};
 
 use super::config::TenantConf;
-use super::remote_timeline_client::index::IndexPart;
+use super::remote_timeline_client::index::{IndexLayerMetadata, IndexPart};
 use super::remote_timeline_client::RemoteTimelineClient;
+use super::secondary::heatmap::{HeatMapLayer, HeatMapTimeline};
 use super::{debug_assert_current_span_has_tenant_and_timeline_id, AttachedTenantConf};
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
@@ -445,6 +446,12 @@ pub(crate) enum CompactFlags {
     ForceRepartition,
 }
 
+impl std::fmt::Debug for Timeline {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "Timeline<{}>", self.timeline_id)
+    }
+}
+
 /// Public interface functions
 impl Timeline {
     /// Get the LSN where this branch was created
@@ -1397,7 +1404,6 @@ impl Timeline {
             Some(self.timeline_id),
             "layer flush task",
             false,
-            self.cancel.child_token(),
             async move {
                 let _guard = guard;
                 let background_ctx = RequestContext::todo_child(TaskKind::LayerFlushTask, DownloadBehavior::Error);
@@ -1749,7 +1755,6 @@ impl Timeline {
             Some(self.timeline_id),
             "initial size calculation",
             false,
-            self.cancel.child_token(),
             // NB: don't log errors here, task_mgr will do that.
             async move {
                 let cancel = task_mgr::shutdown_token();
@@ -1795,6 +1800,9 @@ impl Timeline {
                     permit = wait_for_permit => {
                         (Some(permit), StartCircumstances::AfterBackgroundTasksRateLimit)
                     }
+                    _ = self_ref.cancel.cancelled() => {
+                        return Err(BackgroundCalculationError::Cancelled);
+                    }
                     _ = cancel.cancelled() => {
                         return Err(BackgroundCalculationError::Cancelled);
                     },
@@ -1920,7 +1928,6 @@ impl Timeline {
             Some(self.timeline_id),
             "ondemand logical size calculation",
             false,
-            self.cancel.child_token(),
             async move {
                 let res = self_clone
                     .logical_size_calculation_task(lsn, cause, &ctx)
@@ -2063,6 +2070,55 @@ impl Timeline {
 
         None
     }
+
+    /// The timeline heatmap is a hint to secondary locations from the primary location,
+    /// indicating which layers are currently on-disk on the primary.
+    ///
+    /// None is returned if the Timeline is in a state where uploading a heatmap
+    /// doesn't make sense, such as shutting down or initializing.  The caller
+    /// should treat this as a cue to simply skip doing any heatmap uploading
+    /// for this timeline.
+    pub(crate) async fn generate_heatmap(&self) -> Option<HeatMapTimeline> {
+        let eviction_info = self.get_local_layers_for_disk_usage_eviction().await;
+
+        let remote_client = match &self.remote_client {
+            Some(c) => c,
+            None => return None,
+        };
+
+        let layer_file_names = eviction_info
+            .resident_layers
+            .iter()
+            .map(|l| l.layer.layer_desc().filename())
+            .collect::<Vec<_>>();
+
+        let decorated = match remote_client.get_layers_metadata(layer_file_names) {
+            Ok(d) => d,
+            Err(_) => {
+                // Getting metadata only fails on Timeline in bad state.
+                return None;
+            }
+        };
+
+        let heatmap_layers = std::iter::zip(
+            eviction_info.resident_layers.into_iter(),
+            decorated.into_iter(),
+        )
+        .filter_map(|(layer, remote_info)| {
+            remote_info.map(|remote_info| {
+                HeatMapLayer::new(
+                    layer.layer.layer_desc().filename(),
+                    IndexLayerMetadata::from(remote_info),
+                    layer.last_activity_ts,
+                )
+            })
+        });
+
+        Some(HeatMapTimeline::new(
+            self.timeline_id,
+            heatmap_layers.collect(),
+        ))
+    }
 }
 
 type TraversalId = String;
@@ -4153,7 +4209,6 @@ impl Timeline {
             Some(self.timeline_id),
             "download all remote layers task",
             false,
-            self.cancel.child_token(),
             async move {
                 self_clone.download_all_remote_layers(request).await;
                 let mut status_guard = self_clone.download_all_remote_layers_task_info.write().unwrap();

pageserver/src/tenant/timeline/delete.rs

@@ -6,7 +6,6 @@ use std::{
 use anyhow::Context;
 use pageserver_api::{models::TimelineState, shard::TenantShardId};
 use tokio::sync::OwnedMutexGuard;
-use tokio_util::sync::CancellationToken;
 use tracing::{debug, error, info, instrument, warn, Instrument, Span};
 use utils::{crashsafe, fs_ext, id::TimelineId};
 
@@ -407,7 +406,6 @@ impl DeleteTimelineFlow {
         local_metadata: &TimelineMetadata,
         remote_client: Option<RemoteTimelineClient>,
         deletion_queue_client: DeletionQueueClient,
-        cancel: CancellationToken,
     ) -> anyhow::Result<()> {
         // Note: here we even skip populating layer map. Timeline is essentially uninitialized.
         // RemoteTimelineClient is the only functioning part.
@@ -423,7 +421,6 @@ impl DeleteTimelineFlow {
                 // Important. We dont pass ancestor above because it can be missing.
                 // Thus we need to skip the validation here.
                 CreateTimelineCause::Delete,
-                cancel,
             )
             .context("create_timeline_struct")?;
 
@@ -535,7 +532,6 @@ impl DeleteTimelineFlow {
             Some(timeline_id),
             "timeline_delete",
             false,
-            tenant.cancel.child_token(),
             async move {
                 if let Err(err) = Self::background(guard, conf, &tenant, &timeline).await {
                     error!("Error: {err:#}");

pageserver/src/tenant/timeline/eviction_task.rs

@@ -67,7 +67,6 @@ impl Timeline {
                 self.tenant_shard_id, self.timeline_id
             ),
             false,
-            self.cancel.child_token(),
             async move {
                 let cancel = task_mgr::shutdown_token();
                 tokio::select! {
@@ -167,6 +166,7 @@ impl Timeline {
         let _permit = tokio::select! {
             permit = acquire_permit => permit,
             _ = cancel.cancelled() => return ControlFlow::Break(()),
+            _ = self.cancel.cancelled() => return ControlFlow::Break(()),
         };
 
         // If we evict layers but keep cached values derived from those layers, then

pageserver/src/tenant/timeline/uninit.rs

@@ -19,14 +19,14 @@ use super::Timeline;
 pub struct UninitializedTimeline<'t> {
     pub(crate) owning_tenant: &'t Tenant,
     timeline_id: TimelineId,
-    raw_timeline: Option<(Arc<Timeline>, TimelineUninitMark)>,
+    raw_timeline: Option<(Arc<Timeline>, TimelineUninitMark<'t>)>,
 }
 
 impl<'t> UninitializedTimeline<'t> {
     pub(crate) fn new(
         owning_tenant: &'t Tenant,
         timeline_id: TimelineId,
-        raw_timeline: Option<(Arc<Timeline>, TimelineUninitMark)>,
+        raw_timeline: Option<(Arc<Timeline>, TimelineUninitMark<'t>)>,
     ) -> Self {
         Self {
             owning_tenant,
@@ -169,18 +169,55 @@ pub(crate) fn cleanup_timeline_directory(uninit_mark: TimelineUninitMark) {
 ///
 /// XXX: it's important to create it near the timeline dir, not inside it to ensure timeline dir gets removed first.
 #[must_use]
-pub(crate) struct TimelineUninitMark {
+pub(crate) struct TimelineUninitMark<'t> {
+    owning_tenant: &'t Tenant,
+    timeline_id: TimelineId,
     uninit_mark_deleted: bool,
     uninit_mark_path: Utf8PathBuf,
     pub(crate) timeline_path: Utf8PathBuf,
 }
 
-impl TimelineUninitMark {
-    pub(crate) fn new(uninit_mark_path: Utf8PathBuf, timeline_path: Utf8PathBuf) -> Self {
-        Self {
-            uninit_mark_deleted: false,
-            uninit_mark_path,
-            timeline_path,
+/// Errors when acquiring exclusive access to a timeline ID for creation
+#[derive(thiserror::Error, Debug)]
+pub(crate) enum TimelineExclusionError {
+    #[error("Already exists")]
+    AlreadyExists(Arc<Timeline>),
+    #[error("Already creating")]
+    AlreadyCreating,
+
+    // e.g. I/O errors, or some failure deep in postgres initdb
+    #[error(transparent)]
+    Other(#[from] anyhow::Error),
+}
+
+impl<'t> TimelineUninitMark<'t> {
+    pub(crate) fn new(
+        owning_tenant: &'t Tenant,
+        timeline_id: TimelineId,
+        uninit_mark_path: Utf8PathBuf,
+        timeline_path: Utf8PathBuf,
+    ) -> Result<Self, TimelineExclusionError> {
+        // Lock order: this is the only place we take both locks.  During drop() we only
+        // lock creating_timelines
+        let timelines = owning_tenant.timelines.lock().unwrap();
+        let mut creating_timelines: std::sync::MutexGuard<
+            '_,
+            std::collections::HashSet<TimelineId>,
+        > = owning_tenant.timelines_creating.lock().unwrap();
+
+        if let Some(existing) = timelines.get(&timeline_id) {
+            Err(TimelineExclusionError::AlreadyExists(existing.clone()))
+        } else if creating_timelines.contains(&timeline_id) {
+            Err(TimelineExclusionError::AlreadyCreating)
+        } else {
+            creating_timelines.insert(timeline_id);
+            Ok(Self {
+                owning_tenant,
+                timeline_id,
+                uninit_mark_deleted: false,
+                uninit_mark_path,
+                timeline_path,
+            })
         }
     }
 
@@ -207,7 +244,7 @@ impl TimelineUninitMark {
     }
 }
 
-impl Drop for TimelineUninitMark {
+impl Drop for TimelineUninitMark<'_> {
     fn drop(&mut self) {
         if !self.uninit_mark_deleted {
             if self.timeline_path.exists() {
@@ -226,5 +263,11 @@ impl Drop for TimelineUninitMark {
                 }
             }
         }
+
+        self.owning_tenant
+            .timelines_creating
+            .lock()
+            .unwrap()
+            .remove(&self.timeline_id);
     }
 }

pageserver/src/tenant/timeline/walreceiver.rs

@@ -87,7 +87,6 @@ impl WalReceiver {
             Some(timeline_id),
             &format!("walreceiver for timeline {tenant_shard_id}/{timeline_id}"),
             false,
-            timeline.cancel.child_token(),
             async move {
                 debug_assert_current_span_has_tenant_and_timeline_id();
                 debug!("WAL receiver manager started, connecting to broker");

pageserver/src/tenant/timeline/walreceiver/walreceiver_connection.rs

@@ -167,7 +167,6 @@ pub(super) async fn handle_walreceiver_connection(
         Some(timeline.timeline_id),
         "walreceiver connection",
         false,
-        cancellation.clone(),
         async move {
             debug_assert_current_span_has_tenant_and_timeline_id();
 

pageserver/src/tenant/upload_queue.rs

@@ -8,7 +8,6 @@ use std::fmt::Debug;
 
 use chrono::NaiveDateTime;
 use std::sync::Arc;
-use tokio_util::sync::CancellationToken;
 use tracing::info;
 use utils::lsn::AtomicLsn;
 
@@ -99,8 +98,6 @@ pub(crate) struct UploadQueueInitialized {
     /// wait on until one of them stops the queue. The semaphore is closed when
     /// `RemoteTimelineClient::launch_queued_tasks` encounters `UploadOp::Shutdown`.
     pub(crate) shutdown_ready: Arc<tokio::sync::Semaphore>,
-
-    pub(crate) cancel: CancellationToken,
 }
 
 impl UploadQueueInitialized {
@@ -133,7 +130,6 @@ impl UploadQueue {
     pub(crate) fn initialize_empty_remote(
         &mut self,
         metadata: &TimelineMetadata,
-        cancel: CancellationToken,
     ) -> anyhow::Result<&mut UploadQueueInitialized> {
         match self {
             UploadQueue::Uninitialized => (),
@@ -162,7 +158,6 @@ impl UploadQueue {
             dangling_files: HashMap::new(),
             shutting_down: false,
             shutdown_ready: Arc::new(tokio::sync::Semaphore::new(0)),
-            cancel,
         };
 
         *self = UploadQueue::Initialized(state);
@@ -172,7 +167,6 @@ impl UploadQueue {
     pub(crate) fn initialize_with_current_remote_index_part(
         &mut self,
         index_part: &IndexPart,
-        cancel: CancellationToken,
     ) -> anyhow::Result<&mut UploadQueueInitialized> {
         match self {
             UploadQueue::Uninitialized => (),
@@ -213,7 +207,6 @@ impl UploadQueue {
             dangling_files: HashMap::new(),
             shutting_down: false,
             shutdown_ready: Arc::new(tokio::sync::Semaphore::new(0)),
-            cancel,
         };
 
         *self = UploadQueue::Initialized(state);

pageserver/src/walingest.rs

@@ -2191,7 +2191,7 @@ mod tests {
             .load()
             .await;
         let tline = tenant
-            .bootstrap_timeline(TIMELINE_ID, pg_version, None, &ctx)
+            .bootstrap_timeline_test(TIMELINE_ID, pg_version, None, &ctx)
             .await
             .unwrap();
 

proxy/src/bin/proxy.rs

@@ -7,6 +7,8 @@ use proxy::console;
 use proxy::console::provider::AllowedIpsCache;
 use proxy::console::provider::NodeInfoCache;
 use proxy::http;
+use proxy::rate_limiter::EndpointRateLimiter;
+use proxy::rate_limiter::RateBucketInfo;
 use proxy::rate_limiter::RateLimiterConfig;
 use proxy::usage_metrics;
 
@@ -14,6 +16,7 @@ use anyhow::bail;
 use proxy::config::{self, ProxyConfig};
 use proxy::serverless;
 use std::pin::pin;
+use std::sync::Arc;
 use std::{borrow::Cow, net::SocketAddr};
 use tokio::net::TcpListener;
 use tokio::task::JoinSet;
@@ -113,8 +116,11 @@ struct ProxyCliArgs {
     #[clap(long, default_value = "15s", value_parser = humantime::parse_duration)]
     rate_limiter_timeout: tokio::time::Duration,
     /// Endpoint rate limiter max number of requests per second.
-    #[clap(long, default_value_t = 300)]
-    endpoint_rps_limit: u32,
+    ///
+    /// Provided in the form '<Requests Per Second>@<Bucket Duration Size>'.
+    /// Can be given multiple times for different bucket sizes.
+    #[clap(long, default_values_t = RateBucketInfo::DEFAULT_SET)]
+    endpoint_rps_limit: Vec<RateBucketInfo>,
     /// Initial limit for dynamic rate limiter. Makes sense only if `rate_limit_algorithm` is *not* `None`.
     #[clap(long, default_value_t = 100)]
     initial_limit: usize,
@@ -157,6 +163,8 @@ async fn main() -> anyhow::Result<()> {
     let proxy_listener = TcpListener::bind(proxy_address).await?;
     let cancellation_token = CancellationToken::new();
 
+    let endpoint_rate_limiter = Arc::new(EndpointRateLimiter::new(&config.endpoint_rps_limit));
+
     // client facing tasks. these will exit on error or on cancellation
     // cancellation returns Ok(())
     let mut client_tasks = JoinSet::new();
@@ -164,6 +172,7 @@ async fn main() -> anyhow::Result<()> {
         config,
         proxy_listener,
         cancellation_token.clone(),
+        endpoint_rate_limiter.clone(),
     ));
 
     // TODO: rename the argument to something like serverless.
@@ -177,6 +186,7 @@ async fn main() -> anyhow::Result<()> {
             config,
             serverless_listener,
             cancellation_token.clone(),
+            endpoint_rate_limiter.clone(),
         ));
     }
 
@@ -311,6 +321,10 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
     let authentication_config = AuthenticationConfig {
         scram_protocol_timeout: args.scram_protocol_timeout,
     };
+
+    let mut endpoint_rps_limit = args.endpoint_rps_limit.clone();
+    RateBucketInfo::validate(&mut endpoint_rps_limit)?;
+
     let config = Box::leak(Box::new(ProxyConfig {
         tls_config,
         auth_backend,
@@ -320,8 +334,35 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
         authentication_config,
         require_client_ip: args.require_client_ip,
         disable_ip_check_for_http: args.disable_ip_check_for_http,
-        endpoint_rps_limit: args.endpoint_rps_limit,
+        endpoint_rps_limit,
     }));
 
     Ok(config)
 }
+
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use clap::Parser;
+    use proxy::rate_limiter::RateBucketInfo;
+
+    #[test]
+    fn parse_endpoint_rps_limit() {
+        let config = super::ProxyCliArgs::parse_from([
+            "proxy",
+            "--endpoint-rps-limit",
+            "100@1s",
+            "--endpoint-rps-limit",
+            "20@30s",
+        ]);
+
+        assert_eq!(
+            config.endpoint_rps_limit,
+            vec![
+                RateBucketInfo::new(100, Duration::from_secs(1)),
+                RateBucketInfo::new(20, Duration::from_secs(30)),
+            ]
+        );
+    }
+}

proxy/src/compute.rs

@@ -1,9 +1,13 @@
 use crate::{
-    auth::parse_endpoint_param, cancellation::CancelClosure, console::errors::WakeComputeError,
-    error::UserFacingError, proxy::neon_option,
+    auth::parse_endpoint_param,
+    cancellation::CancelClosure,
+    console::errors::WakeComputeError,
+    error::UserFacingError,
+    proxy::{neon_option, NUM_DB_CONNECTIONS_GAUGE},
 };
 use futures::{FutureExt, TryFutureExt};
 use itertools::Itertools;
+use metrics::IntCounterPairGuard;
 use pq_proto::StartupMessageParams;
 use std::{io, net::SocketAddr, time::Duration};
 use thiserror::Error;
@@ -223,6 +227,8 @@ pub struct PostgresConnection {
     pub params: std::collections::HashMap<String, String>,
     /// Query cancellation token.
     pub cancel_closure: CancelClosure,
+
+    _guage: IntCounterPairGuard,
 }
 
 impl ConnCfg {
@@ -231,6 +237,7 @@ impl ConnCfg {
         &self,
         allow_self_signed_compute: bool,
         timeout: Duration,
+        proto: &'static str,
     ) -> Result<PostgresConnection, ConnectionError> {
         let (socket_addr, stream, host) = self.connect_raw(timeout).await?;
 
@@ -264,6 +271,7 @@ impl ConnCfg {
             stream,
             params,
             cancel_closure,
+            _guage: NUM_DB_CONNECTIONS_GAUGE.with_label_values(&[proto]).guard(),
         };
 
         Ok(connection)

proxy/src/config.rs

@@ -1,4 +1,4 @@
-use crate::auth;
+use crate::{auth, rate_limiter::RateBucketInfo};
 use anyhow::{bail, ensure, Context, Ok};
 use rustls::{sign, Certificate, PrivateKey};
 use sha2::{Digest, Sha256};
@@ -20,7 +20,7 @@ pub struct ProxyConfig {
     pub authentication_config: AuthenticationConfig,
     pub require_client_ip: bool,
     pub disable_ip_check_for_http: bool,
-    pub endpoint_rps_limit: u32,
+    pub endpoint_rps_limit: Vec<RateBucketInfo>,
 }
 
 #[derive(Debug)]

proxy/src/http.rs

@@ -4,14 +4,12 @@
 
 pub mod health_server;
 
-use std::{sync::Arc, time::Duration};
+use std::time::Duration;
 
-use futures::FutureExt;
 pub use reqwest::{Request, Response, StatusCode};
 pub use reqwest_middleware::{ClientWithMiddleware, Error};
 pub use reqwest_retry::{policies::ExponentialBackoff, RetryTransientMiddleware};
 use tokio::time::Instant;
-use tracing::trace;
 
 use crate::{proxy::CONSOLE_REQUEST_LATENCY, rate_limiter, url::ApiUrl};
 use reqwest_middleware::RequestBuilder;
@@ -21,7 +19,7 @@ use reqwest_middleware::RequestBuilder;
 /// We deliberately don't want to replace this with a public static.
 pub fn new_client(rate_limiter_config: rate_limiter::RateLimiterConfig) -> ClientWithMiddleware {
     let client = reqwest::ClientBuilder::new()
-        .dns_resolver(Arc::new(GaiResolver::default()))
+        .http2_prior_knowledge()
         .connection_verbose(true)
         .build()
         .expect("Failed to create http client");
@@ -34,7 +32,6 @@ pub fn new_client(rate_limiter_config: rate_limiter::RateLimiterConfig) -> Clien
 
 pub fn new_client_with_timeout(default_timout: Duration) -> ClientWithMiddleware {
     let timeout_client = reqwest::ClientBuilder::new()
-        .dns_resolver(Arc::new(GaiResolver::default()))
         .connection_verbose(true)
         .timeout(default_timout)
         .build()
@@ -100,37 +97,6 @@ impl Endpoint {
     }
 }
 
-/// https://docs.rs/reqwest/0.11.18/src/reqwest/dns/gai.rs.html
-use hyper::{
-    client::connect::dns::{GaiResolver as HyperGaiResolver, Name},
-    service::Service,
-};
-use reqwest::dns::{Addrs, Resolve, Resolving};
-#[derive(Debug)]
-pub struct GaiResolver(HyperGaiResolver);
-
-impl Default for GaiResolver {
-    fn default() -> Self {
-        Self(HyperGaiResolver::new())
-    }
-}
-
-impl Resolve for GaiResolver {
-    fn resolve(&self, name: Name) -> Resolving {
-        let this = &mut self.0.clone();
-        let start = Instant::now();
-        Box::pin(
-            Service::<Name>::call(this, name.clone()).map(move |result| {
-                let resolve_duration = start.elapsed();
-                trace!(duration = ?resolve_duration, addr = %name, "resolve host complete");
-                result
-                    .map(|addrs| -> Addrs { Box::new(addrs) })
-                    .map_err(|err| -> Box<dyn std::error::Error + Send + Sync> { Box::new(err) })
-            }),
-        )
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

proxy/src/proxy.rs

@@ -9,7 +9,7 @@ use crate::{
     console::{self, errors::WakeComputeError, messages::MetricsAuxInfo, Api},
     http::StatusCode,
     protocol2::WithClientIp,
-    rate_limiter::{EndpointRateLimiter, RateBucketInfo},
+    rate_limiter::EndpointRateLimiter,
     stream::{PqStream, Stream},
     usage_metrics::{Ids, USAGE_METRICS},
 };
@@ -17,7 +17,10 @@ use anyhow::{bail, Context};
 use async_trait::async_trait;
 use futures::TryFutureExt;
 use itertools::Itertools;
-use metrics::{exponential_buckets, register_int_counter_vec, IntCounterVec};
+use metrics::{
+    exponential_buckets, register_int_counter_pair_vec, register_int_counter_vec,
+    IntCounterPairVec, IntCounterVec,
+};
 use once_cell::sync::{Lazy, OnceCell};
 use pq_proto::{BeMessage as Be, FeStartupPacket, StartupMessageParams};
 use prometheus::{
@@ -44,17 +47,10 @@ const RETRY_WAIT_EXPONENT_BASE: f64 = std::f64::consts::SQRT_2;
 const ERR_INSECURE_CONNECTION: &str = "connection is insecure (try using `sslmode=require`)";
 const ERR_PROTO_VIOLATION: &str = "protocol violation";
 
-pub static NUM_DB_CONNECTIONS_OPENED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
+pub static NUM_DB_CONNECTIONS_GAUGE: Lazy<IntCounterPairVec> = Lazy::new(|| {
+    register_int_counter_pair_vec!(
         "proxy_opened_db_connections_total",
         "Number of opened connections to a database.",
-        &["protocol"],
-    )
-    .unwrap()
-});
-
-pub static NUM_DB_CONNECTIONS_CLOSED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
         "proxy_closed_db_connections_total",
         "Number of closed connections to a database.",
         &["protocol"],
@@ -62,17 +58,10 @@ pub static NUM_DB_CONNECTIONS_CLOSED_COUNTER: Lazy<IntCounterVec> = Lazy::new(||
     .unwrap()
 });
 
-pub static NUM_CLIENT_CONNECTION_OPENED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
+pub static NUM_CLIENT_CONNECTION_GAUGE: Lazy<IntCounterPairVec> = Lazy::new(|| {
+    register_int_counter_pair_vec!(
         "proxy_opened_client_connections_total",
         "Number of opened connections from a client.",
-        &["protocol"],
-    )
-    .unwrap()
-});
-
-pub static NUM_CLIENT_CONNECTION_CLOSED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
         "proxy_closed_client_connections_total",
         "Number of closed connections from a client.",
         &["protocol"],
@@ -80,17 +69,10 @@ pub static NUM_CLIENT_CONNECTION_CLOSED_COUNTER: Lazy<IntCounterVec> = Lazy::new
     .unwrap()
 });
 
-pub static NUM_CONNECTIONS_ACCEPTED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
+pub static NUM_CONNECTION_REQUESTS_GAUGE: Lazy<IntCounterPairVec> = Lazy::new(|| {
+    register_int_counter_pair_vec!(
         "proxy_accepted_connections_total",
         "Number of client connections accepted.",
-        &["protocol"],
-    )
-    .unwrap()
-});
-
-pub static NUM_CONNECTIONS_CLOSED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
         "proxy_closed_connections_total",
         "Number of client connections closed.",
         &["protocol"],
@@ -297,6 +279,7 @@ pub async fn task_main(
     config: &'static ProxyConfig,
     listener: tokio::net::TcpListener,
     cancellation_token: CancellationToken,
+    endpoint_rate_limiter: Arc<EndpointRateLimiter>,
 ) -> anyhow::Result<()> {
     scopeguard::defer! {
         info!("proxy has shut down");
@@ -308,10 +291,6 @@ pub async fn task_main(
 
     let connections = tokio_util::task::task_tracker::TaskTracker::new();
     let cancel_map = Arc::new(CancelMap::default());
-    let endpoint_rate_limiter = Arc::new(EndpointRateLimiter::new([RateBucketInfo::new(
-        config.endpoint_rps_limit,
-        time::Duration::from_secs(1),
-    )]));
 
     while let Some(accept_result) =
         run_until_cancelled(listener.accept(), &cancellation_token).await
@@ -431,16 +410,12 @@ pub async fn handle_client<S: AsyncRead + AsyncWrite + Unpin>(
     );
 
     let proto = mode.protocol_label();
-    NUM_CLIENT_CONNECTION_OPENED_COUNTER
+    let _client_gauge = NUM_CLIENT_CONNECTION_GAUGE
         .with_label_values(&[proto])
-        .inc();
-    NUM_CONNECTIONS_ACCEPTED_COUNTER
+        .guard();
+    let _request_gauge = NUM_CONNECTION_REQUESTS_GAUGE
         .with_label_values(&[proto])
-        .inc();
-    scopeguard::defer! {
-        NUM_CLIENT_CONNECTION_CLOSED_COUNTER.with_label_values(&[proto]).inc();
-        NUM_CONNECTIONS_CLOSED_COUNTER.with_label_values(&[proto]).inc();
-    }
+        .guard();
 
     let tls = config.tls_config.as_ref();
 
@@ -587,12 +562,13 @@ pub fn invalidate_cache(node_info: console::CachedNodeInfo) -> compute::ConnCfg
 async fn connect_to_compute_once(
     node_info: &console::CachedNodeInfo,
     timeout: time::Duration,
+    proto: &'static str,
 ) -> Result<PostgresConnection, compute::ConnectionError> {
     let allow_self_signed_compute = node_info.allow_self_signed_compute;
 
     node_info
         .config
-        .connect(allow_self_signed_compute, timeout)
+        .connect(allow_self_signed_compute, timeout, proto)
         .await
 }
 
@@ -613,6 +589,7 @@ pub trait ConnectMechanism {
 pub struct TcpMechanism<'a> {
     /// KV-dictionary with PostgreSQL connection params.
     pub params: &'a StartupMessageParams,
+    pub proto: &'static str,
 }
 
 #[async_trait]
@@ -626,7 +603,7 @@ impl ConnectMechanism for TcpMechanism<'_> {
         node_info: &console::CachedNodeInfo,
         timeout: time::Duration,
     ) -> Result<PostgresConnection, Self::Error> {
-        connect_to_compute_once(node_info, timeout).await
+        connect_to_compute_once(node_info, timeout, self.proto).await
     }
 
     fn update_connect_config(&self, config: &mut compute::ConnCfg) {
@@ -1031,7 +1008,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin> Client<'_, S> {
 
         let aux = node_info.aux.clone();
         let mut node = connect_to_compute(
-            &TcpMechanism { params },
+            &TcpMechanism { params, proto },
             node_info,
             &extra,
             &creds,
@@ -1040,13 +1017,6 @@ impl<S: AsyncRead + AsyncWrite + Unpin> Client<'_, S> {
         .or_else(|e| stream.throw_error(e))
         .await?;
 
-        NUM_DB_CONNECTIONS_OPENED_COUNTER
-            .with_label_values(&[proto])
-            .inc();
-        scopeguard::defer! {
-            NUM_DB_CONNECTIONS_CLOSED_COUNTER.with_label_values(&[proto]).inc();
-        }
-
         prepare_client_connection(&node, session, &mut stream).await?;
         // Before proxy passing, forward to compute whatever data is left in the
         // PqStream input buffer. Normally there is none, but our serverless npm

proxy/src/rate_limiter/aimd.rs

@@ -33,39 +33,6 @@ impl Aimd {
             min_utilisation_threshold: config.aimd_min_utilisation_threshold,
         }
     }
-
-    pub fn decrease_factor(self, factor: f32) -> Self {
-        assert!((0.5..1.0).contains(&factor));
-        Self {
-            decrease_factor: factor,
-            ..self
-        }
-    }
-
-    pub fn increase_by(self, increase: usize) -> Self {
-        assert!(increase > 0);
-        Self {
-            increase_by: increase,
-            ..self
-        }
-    }
-
-    pub fn with_max_limit(self, max: usize) -> Self {
-        assert!(max > 0);
-        Self {
-            max_limit: max,
-            ..self
-        }
-    }
-
-    /// A threshold below which the limit won't be increased. 0.5 = 50%.
-    pub fn with_min_utilisation_threshold(self, min_util: f32) -> Self {
-        assert!(min_util > 0. && min_util < 1.);
-        Self {
-            min_utilisation_threshold: min_util,
-            ..self
-        }
-    }
 }
 
 #[async_trait]

proxy/src/rate_limiter/limiter.rs

@@ -1,10 +1,16 @@
-use std::sync::{
-    atomic::{AtomicUsize, Ordering},
-    Arc,
+use std::{
+    collections::hash_map::RandomState,
+    hash::BuildHasher,
+    sync::{
+        atomic::{AtomicUsize, Ordering},
+        Arc, Mutex,
+    },
 };
 
+use anyhow::bail;
 use dashmap::DashMap;
-use rand::{thread_rng, Rng};
+use itertools::Itertools;
+use rand::{rngs::StdRng, Rng, SeedableRng};
 use smol_str::SmolStr;
 use tokio::sync::{Mutex as AsyncMutex, Semaphore, SemaphorePermit};
 use tokio::time::{timeout, Duration, Instant};
@@ -26,14 +32,11 @@ use super::{
 // saw SNI, before doing TLS handshake. User-side error messages in that case
 // does not look very nice (`SSL SYSCALL error: Undefined error: 0`), so for now
 // I went with a more expensive way that yields user-friendlier error messages.
-//
-// TODO: add a better bucketing here, e.g. not more than 300 requests per second,
-//       and not more than 1000 requests per 10 seconds, etc. Short bursts of reconnects
-//       are normal during redeployments, so we should not block them.
-pub struct EndpointRateLimiter {
-    map: DashMap<SmolStr, Vec<RateBucket>>,
-    info: Vec<RateBucketInfo>,
+pub struct EndpointRateLimiter<Rand = StdRng, Hasher = RandomState> {
+    map: DashMap<SmolStr, Vec<RateBucket>, Hasher>,
+    info: &'static [RateBucketInfo],
     access_count: AtomicUsize,
+    rand: Mutex<Rand>,
 }
 
 #[derive(Clone, Copy)]
@@ -60,27 +63,85 @@ impl RateBucket {
     }
 }
 
+#[derive(Clone, Copy, PartialEq)]
 pub struct RateBucketInfo {
-    interval: Duration,
+    pub interval: Duration,
     // requests per interval
-    max_rpi: u32,
+    pub max_rpi: u32,
+}
+
+impl std::fmt::Display for RateBucketInfo {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let rps = self.max_rpi * 1000 / self.interval.as_millis() as u32;
+        write!(f, "{rps}@{}", humantime::format_duration(self.interval))
+    }
+}
+
+impl std::fmt::Debug for RateBucketInfo {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{self}")
+    }
+}
+
+impl std::str::FromStr for RateBucketInfo {
+    type Err = anyhow::Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let Some((max_rps, interval)) = s.split_once('@') else {
+            bail!("invalid rate info")
+        };
+        let max_rps = max_rps.parse()?;
+        let interval = humantime::parse_duration(interval)?;
+        Ok(Self::new(max_rps, interval))
+    }
 }
 
 impl RateBucketInfo {
-    pub fn new(max_rps: u32, interval: Duration) -> Self {
+    pub const DEFAULT_SET: [Self; 3] = [
+        Self::new(300, Duration::from_secs(1)),
+        Self::new(200, Duration::from_secs(60)),
+        Self::new(100, Duration::from_secs(600)),
+    ];
+
+    pub fn validate(info: &mut [Self]) -> anyhow::Result<()> {
+        info.sort_unstable_by_key(|info| info.interval);
+        let invalid = info
+            .iter()
+            .tuple_windows()
+            .find(|(a, b)| a.max_rpi > b.max_rpi);
+        if let Some((a, b)) = invalid {
+            bail!(
+                "invalid endpoint RPS limits. {b} allows fewer requests per bucket than {a} ({} vs {})",
+                b.max_rpi,
+                a.max_rpi,
+            );
+        }
+
+        Ok(())
+    }
+
+    pub const fn new(max_rps: u32, interval: Duration) -> Self {
         Self {
             interval,
-            max_rpi: max_rps * 1000 / interval.as_millis() as u32,
+            max_rpi: max_rps * interval.as_millis() as u32 / 1000,
         }
     }
 }
 
 impl EndpointRateLimiter {
-    pub fn new(info: impl IntoIterator<Item = RateBucketInfo>) -> Self {
+    pub fn new(info: &'static [RateBucketInfo]) -> Self {
+        Self::new_with_rand_and_hasher(info, StdRng::from_entropy(), RandomState::new())
+    }
+}
+
+impl<R: Rng, S: BuildHasher + Clone> EndpointRateLimiter<R, S> {
+    fn new_with_rand_and_hasher(info: &'static [RateBucketInfo], rand: R, hasher: S) -> Self {
+        info!(buckets = ?info, "endpoint rate limiter");
         Self {
-            info: info.into_iter().collect(),
-            map: DashMap::with_shard_amount(64),
+            info,
+            map: DashMap::with_hasher_and_shard_amount(hasher, 64),
             access_count: AtomicUsize::new(1), // start from 1 to avoid GC on the first request
+            rand: Mutex::new(rand),
         }
     }
 
@@ -107,7 +168,7 @@ impl EndpointRateLimiter {
 
         let should_allow_request = entry
             .iter_mut()
-            .zip(&self.info)
+            .zip(self.info)
             .all(|(bucket, info)| bucket.should_allow_request(info, now));
 
         if should_allow_request {
@@ -127,7 +188,9 @@ impl EndpointRateLimiter {
             self.map.len()
         );
         let n = self.map.shards().len();
-        let shard = thread_rng().gen_range(0..n);
+        // this lock is ok as the periodic cycle of do_gc makes this very unlikely to collide
+        // (impossible, infact, unless we have 2048 threads)
+        let shard = self.rand.lock().unwrap().gen_range(0..n);
         self.map.shards()[shard].write().clear();
     }
 }
@@ -170,7 +233,6 @@ pub struct Token<'t> {
 #[derive(Debug, Clone, Copy)]
 pub struct LimiterState {
     limit: usize,
-    available: usize,
     in_flight: usize,
 }
 
@@ -348,11 +410,7 @@ impl Limiter {
     pub fn state(&self) -> LimiterState {
         let limit = self.limits.load(Ordering::Relaxed);
         let in_flight = self.in_flight.load(Ordering::Relaxed);
-        LimiterState {
-            limit,
-            available: limit.saturating_sub(in_flight),
-            in_flight,
-        }
+        LimiterState { limit, in_flight }
     }
 }
 
@@ -365,13 +423,6 @@ impl<'t> Token<'t> {
         }
     }
 
-    #[cfg(test)]
-    pub fn set_latency(&mut self, latency: Duration) {
-        use std::ops::Sub;
-
-        self.start = Instant::now().sub(latency);
-    }
-
     pub fn forget(&mut self) {
         if let Some(permit) = self.permit.take() {
             permit.forget();
@@ -390,10 +441,6 @@ impl LimiterState {
     pub fn limit(&self) -> usize {
         self.limit
     }
-    /// The amount of concurrency available to use.
-    pub fn available(&self) -> usize {
-        self.available
-    }
     /// The number of jobs in flight.
     pub fn in_flight(&self) -> usize {
         self.in_flight
@@ -441,12 +488,16 @@ impl reqwest_middleware::Middleware for Limiter {
 
 #[cfg(test)]
 mod tests {
-    use std::{pin::pin, task::Context, time::Duration};
+    use std::{hash::BuildHasherDefault, pin::pin, task::Context, time::Duration};
 
     use futures::{task::noop_waker_ref, Future};
+    use rand::SeedableRng;
+    use rustc_hash::FxHasher;
+    use smol_str::SmolStr;
+    use tokio::time;
 
-    use super::{Limiter, Outcome};
-    use crate::rate_limiter::RateLimitAlgorithm;
+    use super::{EndpointRateLimiter, Limiter, Outcome};
+    use crate::rate_limiter::{RateBucketInfo, RateLimitAlgorithm};
 
     #[tokio::test]
     async fn it_works() {
@@ -555,4 +606,105 @@ mod tests {
         limiter.release(token1, None).await;
         limiter.release(token2, None).await;
     }
+
+    #[test]
+    fn rate_bucket_rpi() {
+        let rate_bucket = RateBucketInfo::new(50, Duration::from_secs(5));
+        assert_eq!(rate_bucket.max_rpi, 50 * 5);
+
+        let rate_bucket = RateBucketInfo::new(50, Duration::from_millis(500));
+        assert_eq!(rate_bucket.max_rpi, 50 / 2);
+    }
+
+    #[test]
+    fn rate_bucket_parse() {
+        let rate_bucket: RateBucketInfo = "100@10s".parse().unwrap();
+        assert_eq!(rate_bucket.interval, Duration::from_secs(10));
+        assert_eq!(rate_bucket.max_rpi, 100 * 10);
+        assert_eq!(rate_bucket.to_string(), "100@10s");
+
+        let rate_bucket: RateBucketInfo = "100@1m".parse().unwrap();
+        assert_eq!(rate_bucket.interval, Duration::from_secs(60));
+        assert_eq!(rate_bucket.max_rpi, 100 * 60);
+        assert_eq!(rate_bucket.to_string(), "100@1m");
+    }
+
+    #[test]
+    fn default_rate_buckets() {
+        let mut defaults = RateBucketInfo::DEFAULT_SET;
+        RateBucketInfo::validate(&mut defaults[..]).unwrap();
+    }
+
+    #[test]
+    #[should_panic = "invalid endpoint RPS limits. 10@10s allows fewer requests per bucket than 300@1s (100 vs 300)"]
+    fn rate_buckets_validate() {
+        let mut rates: Vec<RateBucketInfo> = ["300@1s", "10@10s"]
+            .into_iter()
+            .map(|s| s.parse().unwrap())
+            .collect();
+        RateBucketInfo::validate(&mut rates).unwrap();
+    }
+
+    #[tokio::test]
+    async fn test_rate_limits() {
+        let mut rates: Vec<RateBucketInfo> = ["100@1s", "20@30s"]
+            .into_iter()
+            .map(|s| s.parse().unwrap())
+            .collect();
+        RateBucketInfo::validate(&mut rates).unwrap();
+        let limiter = EndpointRateLimiter::new(Vec::leak(rates));
+
+        let endpoint = SmolStr::from("ep-my-endpoint-1234");
+
+        time::pause();
+
+        for _ in 0..100 {
+            assert!(limiter.check(endpoint.clone()));
+        }
+        // more connections fail
+        assert!(!limiter.check(endpoint.clone()));
+
+        // fail even after 500ms as it's in the same bucket
+        time::advance(time::Duration::from_millis(500)).await;
+        assert!(!limiter.check(endpoint.clone()));
+
+        // after a full 1s, 100 requests are allowed again
+        time::advance(time::Duration::from_millis(500)).await;
+        for _ in 1..6 {
+            for _ in 0..100 {
+                assert!(limiter.check(endpoint.clone()));
+            }
+            time::advance(time::Duration::from_millis(1000)).await;
+        }
+
+        // more connections after 600 will exceed the 20rps@30s limit
+        assert!(!limiter.check(endpoint.clone()));
+
+        // will still fail before the 30 second limit
+        time::advance(time::Duration::from_millis(30_000 - 6_000 - 1)).await;
+        assert!(!limiter.check(endpoint.clone()));
+
+        // after the full 30 seconds, 100 requests are allowed again
+        time::advance(time::Duration::from_millis(1)).await;
+        for _ in 0..100 {
+            assert!(limiter.check(endpoint.clone()));
+        }
+    }
+
+    #[tokio::test]
+    async fn test_rate_limits_gc() {
+        // fixed seeded random/hasher to ensure that the test is not flaky
+        let rand = rand::rngs::StdRng::from_seed([1; 32]);
+        let hasher = BuildHasherDefault::<FxHasher>::default();
+
+        let limiter = EndpointRateLimiter::new_with_rand_and_hasher(
+            &RateBucketInfo::DEFAULT_SET,
+            rand,
+            hasher,
+        );
+        for i in 0..1_000_000 {
+            limiter.check(format!("{i}").into());
+        }
+        assert!(limiter.map.len() < 150_000);
+    }
 }

proxy/src/serverless.rs

@@ -8,14 +8,14 @@ mod websocket;
 
 use anyhow::bail;
 use hyper::StatusCode;
+use metrics::IntCounterPairGuard;
 pub use reqwest_middleware::{ClientWithMiddleware, Error};
 pub use reqwest_retry::{policies::ExponentialBackoff, RetryTransientMiddleware};
-use tokio::time;
 use tokio_util::task::TaskTracker;
 
 use crate::protocol2::{ProxyProtocolAccept, WithClientIp};
-use crate::proxy::{NUM_CLIENT_CONNECTION_CLOSED_COUNTER, NUM_CLIENT_CONNECTION_OPENED_COUNTER};
-use crate::rate_limiter::{EndpointRateLimiter, RateBucketInfo};
+use crate::proxy::NUM_CLIENT_CONNECTION_GAUGE;
+use crate::rate_limiter::EndpointRateLimiter;
 use crate::{cancellation::CancelMap, config::ProxyConfig};
 use futures::StreamExt;
 use hyper::{
@@ -39,16 +39,13 @@ pub async fn task_main(
     config: &'static ProxyConfig,
     ws_listener: TcpListener,
     cancellation_token: CancellationToken,
+    endpoint_rate_limiter: Arc<EndpointRateLimiter>,
 ) -> anyhow::Result<()> {
     scopeguard::defer! {
         info!("websocket server has shut down");
     }
 
     let conn_pool = conn_pool::GlobalConnPool::new(config);
-    let endpoint_rate_limiter = Arc::new(EndpointRateLimiter::new([RateBucketInfo::new(
-        config.endpoint_rps_limit,
-        time::Duration::from_secs(1),
-    )]));
 
     // shutdown the connection pool
     tokio::spawn({
@@ -153,22 +150,17 @@ pub async fn task_main(
 
 struct MetricService<S> {
     inner: S,
+    _gauge: IntCounterPairGuard,
 }
 
 impl<S> MetricService<S> {
     fn new(inner: S) -> MetricService<S> {
-        NUM_CLIENT_CONNECTION_OPENED_COUNTER
-            .with_label_values(&["http"])
-            .inc();
-        MetricService { inner }
-    }
-}
-
-impl<S> Drop for MetricService<S> {
-    fn drop(&mut self) {
-        NUM_CLIENT_CONNECTION_CLOSED_COUNTER
-            .with_label_values(&["http"])
-            .inc();
+        MetricService {
+            inner,
+            _gauge: NUM_CLIENT_CONNECTION_GAUGE
+                .with_label_values(&["http"])
+                .guard(),
+        }
     }
 }
 
@@ -252,7 +244,7 @@ async fn request_handler(
             .header("Access-Control-Allow-Origin", "*")
             .header(
                 "Access-Control-Allow-Headers",
-                "Neon-Connection-String, Neon-Raw-Text-Output, Neon-Array-Mode, Neon-Pool-Opt-In",
+                "Neon-Connection-String, Neon-Raw-Text-Output, Neon-Array-Mode, Neon-Pool-Opt-In, Neon-Batch-Read-Only, Neon-Batch-Isolation-Level",
             )
             .header("Access-Control-Max-Age", "86400" /* 24 hours */)
             .status(StatusCode::OK) // 204 is also valid, but see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/OPTIONS#status_code

proxy/src/serverless/conn_pool.rs

@@ -24,10 +24,7 @@ use tokio_postgres::{AsyncMessage, ReadyForQueryStatus};
 use crate::{
     auth::{self, backend::ComputeUserInfo, check_peer_addr_is_in_list},
     console,
-    proxy::{
-        neon_options, LatencyTimer, NUM_DB_CONNECTIONS_CLOSED_COUNTER,
-        NUM_DB_CONNECTIONS_OPENED_COUNTER,
-    },
+    proxy::{neon_options, LatencyTimer, NUM_DB_CONNECTIONS_GAUGE},
     usage_metrics::{Ids, MetricCounter, USAGE_METRICS},
 };
 use crate::{compute, config};
@@ -477,6 +474,11 @@ async fn connect_to_compute_once(
         .connect_timeout(timeout)
         .connect(tokio_postgres::NoTls)
         .await?;
+
+    let conn_gauge = NUM_DB_CONNECTIONS_GAUGE
+        .with_label_values(&["http"])
+        .guard();
+
     tracing::Span::current().record("pid", &tracing::field::display(client.get_process_id()));
 
     let (tx, mut rx) = tokio::sync::watch::channel(session);
@@ -492,10 +494,7 @@ async fn connect_to_compute_once(
 
     tokio::spawn(
         async move {
-            NUM_DB_CONNECTIONS_OPENED_COUNTER.with_label_values(&["http"]).inc();
-            scopeguard::defer! {
-                NUM_DB_CONNECTIONS_CLOSED_COUNTER.with_label_values(&["http"]).inc();
-            }
+            let _conn_gauge = conn_gauge;
             poll_fn(move |cx| {
                 if matches!(rx.has_changed(), Ok(true)) {
                     session = *rx.borrow_and_update();

proxy/src/serverless/sql_over_http.rs

@@ -29,7 +29,7 @@ use utils::http::error::ApiError;
 use utils::http::json::json_response;
 
 use crate::config::HttpConfig;
-use crate::proxy::{NUM_CONNECTIONS_ACCEPTED_COUNTER, NUM_CONNECTIONS_CLOSED_COUNTER};
+use crate::proxy::NUM_CONNECTION_REQUESTS_GAUGE;
 
 use super::conn_pool::ConnInfo;
 use super::conn_pool::GlobalConnPool;
@@ -303,12 +303,9 @@ async fn handle_inner(
     session_id: uuid::Uuid,
     peer_addr: IpAddr,
 ) -> anyhow::Result<Response<Body>> {
-    NUM_CONNECTIONS_ACCEPTED_COUNTER
+    let _request_gauge = NUM_CONNECTION_REQUESTS_GAUGE
         .with_label_values(&["http"])
-        .inc();
-    scopeguard::defer! {
-        NUM_CONNECTIONS_CLOSED_COUNTER.with_label_values(&["http"]).inc();
-    }
+        .guard();
 
     //
     // Determine the destination and connection params

proxy/src/serverless/websocket.rs

@@ -27,15 +27,15 @@ use sync_wrapper::SyncWrapper;
 pin_project! {
     /// This is a wrapper around a [`WebSocketStream`] that
     /// implements [`AsyncRead`] and [`AsyncWrite`].
-    pub struct WebSocketRw {
+    pub struct WebSocketRw<S = Upgraded> {
         #[pin]
-        stream: SyncWrapper<WebSocketStream<Upgraded>>,
+        stream: SyncWrapper<WebSocketStream<S>>,
         bytes: Bytes,
     }
 }
 
-impl WebSocketRw {
-    pub fn new(stream: WebSocketStream<Upgraded>) -> Self {
+impl<S> WebSocketRw<S> {
+    pub fn new(stream: WebSocketStream<S>) -> Self {
         Self {
             stream: stream.into(),
             bytes: Bytes::new(),
@@ -43,7 +43,7 @@ impl WebSocketRw {
     }
 }
 
-impl AsyncWrite for WebSocketRw {
+impl<S: AsyncRead + AsyncWrite + Unpin> AsyncWrite for WebSocketRw<S> {
     fn poll_write(
         self: Pin<&mut Self>,
         cx: &mut Context<'_>,
@@ -69,7 +69,7 @@ impl AsyncWrite for WebSocketRw {
     }
 }
 
-impl AsyncRead for WebSocketRw {
+impl<S: AsyncRead + AsyncWrite + Unpin> AsyncRead for WebSocketRw<S> {
     fn poll_read(
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
@@ -86,7 +86,7 @@ impl AsyncRead for WebSocketRw {
     }
 }
 
-impl AsyncBufRead for WebSocketRw {
+impl<S: AsyncRead + AsyncWrite + Unpin> AsyncBufRead for WebSocketRw<S> {
     fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<&[u8]>> {
         // Please refer to poll_fill_buf's documentation.
         const EOF: Poll<io::Result<&[u8]>> = Poll::Ready(Ok(&[]));
@@ -151,3 +151,60 @@ pub async fn serve_websocket(
     .await?;
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use std::pin::pin;
+
+    use futures::{SinkExt, StreamExt};
+    use hyper_tungstenite::{
+        tungstenite::{protocol::Role, Message},
+        WebSocketStream,
+    };
+    use tokio::{
+        io::{duplex, AsyncReadExt, AsyncWriteExt},
+        task::JoinSet,
+    };
+
+    use super::WebSocketRw;
+
+    #[tokio::test]
+    async fn websocket_stream_wrapper_happy_path() {
+        let (stream1, stream2) = duplex(1024);
+
+        let mut js = JoinSet::new();
+
+        js.spawn(async move {
+            let mut client = WebSocketStream::from_raw_socket(stream1, Role::Client, None).await;
+
+            client
+                .send(Message::Binary(b"hello world".to_vec()))
+                .await
+                .unwrap();
+
+            let message = client.next().await.unwrap().unwrap();
+            assert_eq!(message, Message::Binary(b"websockets are cool".to_vec()));
+
+            client.close(None).await.unwrap();
+        });
+
+        js.spawn(async move {
+            let mut rw = pin!(WebSocketRw::new(
+                WebSocketStream::from_raw_socket(stream2, Role::Server, None).await
+            ));
+
+            let mut buf = vec![0; 1024];
+            let n = rw.read(&mut buf).await.unwrap();
+            assert_eq!(&buf[..n], b"hello world");
+
+            rw.write_all(b"websockets are cool").await.unwrap();
+            rw.flush().await.unwrap();
+
+            let n = rw.read_to_end(&mut buf).await.unwrap();
+            assert_eq!(n, 0);
+        });
+
+        js.join_next().await.unwrap().unwrap();
+        js.join_next().await.unwrap().unwrap();
+    }
+}

safekeeper/src/handler.rs

@@ -11,7 +11,7 @@ use tracing::{debug, info, info_span, Instrument};
 use crate::auth::check_permission;
 use crate::json_ctrl::{handle_json_ctrl, AppendLogicalMessage};
 
-use crate::metrics::{TrafficMetrics, PG_QUERIES_FINISHED, PG_QUERIES_RECEIVED};
+use crate::metrics::{TrafficMetrics, PG_QUERIES_GAUGE};
 use crate::safekeeper::Term;
 use crate::timeline::TimelineError;
 use crate::wal_service::ConnectionId;
@@ -210,10 +210,7 @@ impl<IO: AsyncRead + AsyncWrite + Unpin + Send> postgres_backend::Handler<IO>
         let cmd = parse_cmd(query_string)?;
         let cmd_str = cmd_to_string(&cmd);
 
-        PG_QUERIES_RECEIVED.with_label_values(&[cmd_str]).inc();
-        scopeguard::defer! {
-            PG_QUERIES_FINISHED.with_label_values(&[cmd_str]).inc();
-        }
+        let _guard = PG_QUERIES_GAUGE.with_label_values(&[cmd_str]).guard();
 
         info!("got query {:?}", query_string);
 

safekeeper/src/metrics.rs

@@ -11,7 +11,8 @@ use futures::Future;
 use metrics::{
     core::{AtomicU64, Collector, Desc, GenericCounter, GenericGaugeVec, Opts},
     proto::MetricFamily,
-    register_int_counter, register_int_counter_vec, Gauge, IntCounter, IntCounterVec, IntGaugeVec,
+    register_int_counter, register_int_counter_pair_vec, register_int_counter_vec, Gauge,
+    IntCounter, IntCounterPairVec, IntCounterVec, IntGaugeVec,
 };
 use once_cell::sync::Lazy;
 
@@ -89,16 +90,10 @@ pub static BROKER_PULLED_UPDATES: Lazy<IntCounterVec> = Lazy::new(|| {
     )
     .expect("Failed to register safekeeper_broker_pulled_updates_total counter")
 });
-pub static PG_QUERIES_RECEIVED: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
+pub static PG_QUERIES_GAUGE: Lazy<IntCounterPairVec> = Lazy::new(|| {
+    register_int_counter_pair_vec!(
         "safekeeper_pg_queries_received_total",
         "Number of queries received through pg protocol",
-        &["query"]
-    )
-    .expect("Failed to register safekeeper_pg_queries_received_total counter")
-});
-pub static PG_QUERIES_FINISHED: Lazy<IntCounterVec> = Lazy::new(|| {
-    register_int_counter_vec!(
         "safekeeper_pg_queries_finished_total",
         "Number of queries finished through pg protocol",
         &["query"]

test_runner/fixtures/neon_fixtures.py

@@ -2945,7 +2945,7 @@ class Safekeeper:
         tli_dir = self.timeline_dir(tenant_id, timeline_id)
         segments = []
         for _, _, filenames in os.walk(tli_dir):
-            segments.extend([f for f in filenames if f != "safekeeper.control"])
+            segments.extend([f for f in filenames if not f.startswith("safekeeper.control")])
         segments.sort()
         return segments
 

test_runner/fixtures/pageserver/http.py

@@ -322,6 +322,10 @@ class PageserverHttpClient(requests.Session):
         self.verbose_error(res)
         return TenantConfig.from_json(res.json())
 
+    def tenant_heatmap_upload(self, tenant_id: TenantId):
+        res = self.post(f"http://localhost:{self.port}/v1/tenant/{tenant_id}/heatmap_upload")
+        self.verbose_error(res)
+
     def set_tenant_config(self, tenant_id: TenantId, config: dict[str, Any]):
         assert "tenant_id" not in config.keys()
         res = self.put(

test_runner/fixtures/remote_storage.py

@@ -16,6 +16,7 @@ from fixtures.log_helper import log
 from fixtures.types import TenantId, TimelineId
 
 TIMELINE_INDEX_PART_FILE_NAME = "index_part.json"
+TENANT_HEATMAP_FILE_NAME = "heatmap-v1.json"
 
 
 @enum.unique
@@ -133,6 +134,13 @@ class LocalFsStorage:
         with self.index_path(tenant_id, timeline_id).open("r") as f:
             return json.load(f)
 
+    def heatmap_path(self, tenant_id: TenantId) -> Path:
+        return self.tenant_path(tenant_id) / TENANT_HEATMAP_FILE_NAME
+
+    def heatmap_content(self, tenant_id):
+        with self.heatmap_path(tenant_id).open("r") as f:
+            return json.load(f)
+
     def to_toml_inline_table(self) -> str:
         rv = {
             "local_path": str(self.root),

test_runner/regress/test_attach_tenant_config.py

@@ -163,6 +163,7 @@ def test_fully_custom_config(positive_env: NeonEnv):
         "gc_feedback": True,
         "gc_horizon": 23 * (1024 * 1024),
         "gc_period": "2h 13m",
+        "heatmap_period": "10m",
         "image_creation_threshold": 7,
         "pitr_interval": "1m",
         "lagging_wal_timeout": "23m",

test_runner/regress/test_branching.py

@@ -1,8 +1,7 @@
 import random
 import threading
 import time
-from queue import SimpleQueue
-from typing import Any, Dict, List, Union
+from typing import List
 
 import pytest
 from fixtures.log_helper import log
@@ -239,92 +238,6 @@ def test_cannot_branch_from_non_uploaded_branch(neon_env_builder: NeonEnvBuilder
         t.join()
 
 
-def test_competing_branchings_from_loading_race_to_ok_or_err(neon_env_builder: NeonEnvBuilder):
-    """
-    If the activate only after upload is used, then retries could become competing.
-    """
-
-    env = neon_env_builder.init_configs()
-    env.start()
-
-    env.pageserver.allowed_errors.extend(
-        [
-            ".*request{method=POST path=/v1/tenant/.*/timeline request_id=.*}: request was dropped before completing.*",
-            ".*Error processing HTTP request: InternalServerError\\(Timeline .*/.* already exists in pageserver's memory",
-        ]
-    )
-    ps_http = env.pageserver.http_client()
-
-    # pause all uploads
-    ps_http.configure_failpoints(("before-upload-index-pausable", "pause"))
-    env.pageserver.tenant_create(env.initial_tenant)
-
-    def start_creating_timeline():
-        ps_http.timeline_create(
-            env.pg_version, env.initial_tenant, env.initial_timeline, timeout=60
-        )
-
-    create_root = threading.Thread(target=start_creating_timeline)
-
-    branch_id = TimelineId.generate()
-
-    queue: SimpleQueue[Union[Dict[Any, Any], Exception]] = SimpleQueue()
-    barrier = threading.Barrier(3)
-
-    def try_branch():
-        barrier.wait()
-        barrier.wait()
-        try:
-            ret = ps_http.timeline_create(
-                env.pg_version,
-                env.initial_tenant,
-                branch_id,
-                ancestor_timeline_id=env.initial_timeline,
-                timeout=5,
-            )
-            queue.put(ret)
-        except Exception as e:
-            queue.put(e)
-
-    threads = [threading.Thread(target=try_branch) for _ in range(2)]
-
-    try:
-        create_root.start()
-
-        for t in threads:
-            t.start()
-
-        wait_until_paused(env, "before-upload-index-pausable")
-
-        barrier.wait()
-        ps_http.configure_failpoints(("before-upload-index-pausable", "off"))
-        barrier.wait()
-
-        # now both requests race to branch, only one can win because they take gc_cs, Tenant::timelines or marker files
-        first = queue.get()
-        second = queue.get()
-
-        log.info(first)
-        log.info(second)
-
-        (succeeded, failed) = (first, second) if isinstance(second, Exception) else (second, first)
-        assert isinstance(failed, Exception)
-        assert isinstance(succeeded, Dict)
-
-        # there's multiple valid status codes:
-        # - Timeline x/y already exists
-        # - whatever 409 response says, but that is a subclass of PageserverApiException
-        assert isinstance(failed, PageserverApiException)
-        assert succeeded["state"] == "Active"
-    finally:
-        # we might still have the failpoint active
-        env.pageserver.stop(immediate=True)
-
-        for t in threads:
-            t.join()
-        create_root.join()
-
-
 def test_non_uploaded_root_timeline_is_deleted_after_restart(neon_env_builder: NeonEnvBuilder):
     """
     Check that a timeline is deleted locally on subsequent restart if it never successfully uploaded during creation.

test_runner/regress/test_compatibility.py

@@ -273,9 +273,24 @@ def check_neon_works(env: NeonEnv, test_output_dir: Path, sql_dump_path: Path, r
     timeline_id = env.initial_timeline
     pg_version = env.pg_version
 
-    shutil.rmtree(repo_dir / "local_fs_remote_storage")
+    # Delete all files from local_fs_remote_storage except initdb.tar.zst,
+    # the file is required for `timeline_create` with `existing_initdb_timeline_id`.
+    #
+    # TODO: switch to Path.walk() in Python 3.12
+    # for dirpath, _dirnames, filenames in (repo_dir / "local_fs_remote_storage").walk():
+    for dirpath, _dirnames, filenames in os.walk(repo_dir / "local_fs_remote_storage"):
+        for filename in filenames:
+            if filename != "initdb.tar.zst":
+                (Path(dirpath) / filename).unlink()
+
     timeline_delete_wait_completed(pageserver_http, tenant_id, timeline_id)
-    pageserver_http.timeline_create(pg_version, tenant_id, timeline_id)
+    pageserver_http.timeline_create(
+        pg_version=pg_version,
+        tenant_id=tenant_id,
+        new_timeline_id=timeline_id,
+        existing_initdb_timeline_id=timeline_id,
+    )
+
     pg_bin.run_capture(
         ["pg_dumpall", f"--dbname={connstr}", f"--file={test_output_dir / 'dump-from-wal.sql'}"]
     )

test_runner/regress/test_pageserver_secondary.py

@@ -4,7 +4,7 @@ from typing import Any, Dict, Optional
 import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnvBuilder, NeonPageserver
-from fixtures.remote_storage import RemoteStorageKind
+from fixtures.remote_storage import LocalFsStorage, RemoteStorageKind
 from fixtures.types import TenantId, TimelineId
 from fixtures.utils import wait_until
 from fixtures.workload import Workload
@@ -330,3 +330,46 @@ def test_live_migration(neon_env_builder: NeonEnvBuilder):
 
     workload.churn_rows(64, pageserver_b.id)
     workload.validate(pageserver_b.id)
+
+
+def test_heatmap_uploads(neon_env_builder: NeonEnvBuilder):
+    """
+    Test the sequence of location states that are used in a live migration.
+    """
+    env = neon_env_builder.init_start()  # initial_tenant_conf=TENANT_CONF)
+    assert isinstance(env.pageserver_remote_storage, LocalFsStorage)
+
+    tenant_id = env.initial_tenant
+    timeline_id = env.initial_timeline
+
+    # Write some data so that we have some layers
+    workload = Workload(env, tenant_id, timeline_id)
+    workload.init(env.pageservers[0].id)
+
+    # Write some layers and upload a heatmap
+    workload.write_rows(256, env.pageservers[0].id)
+    env.pageserver.http_client().tenant_heatmap_upload(tenant_id)
+
+    def validate_heatmap(heatmap):
+        assert len(heatmap["timelines"]) == 1
+        assert heatmap["timelines"][0]["timeline_id"] == str(timeline_id)
+        assert len(heatmap["timelines"][0]["layers"]) > 0
+        layers = heatmap["timelines"][0]["layers"]
+
+        # Each layer appears at most once
+        assert len(set(layer["name"] for layer in layers)) == len(layers)
+
+    # Download and inspect the heatmap that the pageserver uploaded
+    heatmap_first = env.pageserver_remote_storage.heatmap_content(tenant_id)
+    log.info(f"Read back heatmap: {heatmap_first}")
+    validate_heatmap(heatmap_first)
+
+    # Do some more I/O to generate more layers
+    workload.churn_rows(64, env.pageservers[0].id)
+    env.pageserver.http_client().tenant_heatmap_upload(tenant_id)
+
+    # Ensure that another heatmap upload includes the new layers
+    heatmap_second = env.pageserver_remote_storage.heatmap_content(tenant_id)
+    log.info(f"Read back heatmap: {heatmap_second}")
+    assert heatmap_second != heatmap_first
+    validate_heatmap(heatmap_second)

test_runner/regress/test_wal_restore.py

@@ -1,7 +1,6 @@
 import sys
 import tarfile
 import tempfile
-import time
 from pathlib import Path
 
 import pytest
@@ -12,6 +11,7 @@ from fixtures.neon_fixtures import (
     PgBin,
     VanillaPostgres,
 )
+from fixtures.pageserver.utils import timeline_delete_wait_completed
 from fixtures.port_distributor import PortDistributor
 from fixtures.remote_storage import LocalFsStorage
 from fixtures.types import Lsn, TenantId, TimelineId
@@ -128,10 +128,7 @@ def test_wal_restore_initdb(
         assert restored.safe_psql("select count(*) from t", user="cloud_admin") == [(300000,)]
 
 
-def test_wal_restore_http(
-    neon_env_builder: NeonEnvBuilder,
-    test_output_dir: Path,
-):
+def test_wal_restore_http(neon_env_builder: NeonEnvBuilder):
     env = neon_env_builder.init_start()
     endpoint = env.endpoints.create_start("main")
     endpoint.safe_psql("create table t as select generate_series(1,300000)")
@@ -145,15 +142,7 @@ def test_wal_restore_http(
 
     assert isinstance(env.pageserver_remote_storage, LocalFsStorage)
 
-    test_output_dir / "initdb.tar.zst"
-
-    (env.pageserver_remote_storage.timeline_path(tenant_id, timeline_id) / "initdb.tar.zst")
-
-    ps_client.timeline_delete(tenant_id, timeline_id)
-    time.sleep(2)
-
-    # verify that it is indeed deleted
-    # TODO
+    timeline_delete_wait_completed(ps_client, tenant_id, timeline_id)
 
     # issue the restoration command
     ps_client.timeline_create(

vendor/revisions.json

@@ -1,5 +1,5 @@
 {
-    "postgres-v16": "e3a22b72922055f9212eca12700190f118578362",
-    "postgres-v15": "bc88f539312fcc4bb292ce94ae9db09ab6656e8a",
-    "postgres-v14": "dd067cf656f6810a25aca6025633d32d02c5085a"
+    "postgres-v16": "863b71572bc441581efb3bbee2ad18af037be1bb",
+    "postgres-v15": "24333abb81a9ecae4541019478f0bf7d0b289df7",
+    "postgres-v14": "0bb356aa0cd1582112926fbcf0b5370222c2db6d"
 }