Unify remote index loading

## Problem

Currently http timeout is hardcoded to 15 seconds.

## Summary of changes

Added an option to configure it via cli args.

Context: https://neondb.slack.com/archives/C04DGM6SMTM/p1696941726151899

Dockerfile.compute-node

@@ -224,8 +224,8 @@ RUN wget https://github.com/df7cb/postgresql-unit/archive/refs/tags/7.7.tar.gz -
 FROM build-deps AS vector-pg-build
 COPY --from=pg-build /usr/local/pgsql/ /usr/local/pgsql/
 
-RUN wget https://github.com/pgvector/pgvector/archive/refs/tags/v0.5.0.tar.gz -O pgvector.tar.gz && \
-    echo "d8aa3504b215467ca528525a6de12c3f85f9891b091ce0e5864dd8a9b757f77b pgvector.tar.gz" | sha256sum --check && \
+RUN wget https://github.com/pgvector/pgvector/archive/refs/tags/v0.5.1.tar.gz -O pgvector.tar.gz && \
+    echo "cc7a8e034a96e30a819911ac79d32f6bc47bdd1aa2de4d7d4904e26b83209dc8 pgvector.tar.gz" | sha256sum --check && \
     mkdir pgvector-src && cd pgvector-src && tar xvzf ../pgvector.tar.gz --strip-components=1 -C . && \
     make -j $(getconf _NPROCESSORS_ONLN) PG_CONFIG=/usr/local/pgsql/bin/pg_config && \
     make -j $(getconf _NPROCESSORS_ONLN) install PG_CONFIG=/usr/local/pgsql/bin/pg_config && \

libs/remote_storage/src/s3_bucket.rs

@@ -4,7 +4,7 @@
 //! allowing multiple api users to independently work with the same S3 bucket, if
 //! their bucket prefixes are both specified and different.
 
-use std::sync::Arc;
+use std::{borrow::Cow, sync::Arc};
 
 use anyhow::Context;
 use aws_config::{
@@ -556,6 +556,20 @@ impl RemoteStorage for S3Bucket {
                         .deleted_objects_total
                         .inc_by(chunk.len() as u64);
                     if let Some(errors) = resp.errors {
+                        // Log a bounded number of the errors within the response:
+                        // these requests can carry 1000 keys so logging each one
+                        // would be too verbose, especially as errors may lead us
+                        // to retry repeatedly.
+                        const LOG_UP_TO_N_ERRORS: usize = 10;
+                        for e in errors.iter().take(LOG_UP_TO_N_ERRORS) {
+                            tracing::warn!(
+                                "DeleteObjects key {} failed: {}: {}",
+                                e.key.as_ref().map(Cow::from).unwrap_or("".into()),
+                                e.code.as_ref().map(Cow::from).unwrap_or("".into()),
+                                e.message.as_ref().map(Cow::from).unwrap_or("".into())
+                            );
+                        }
+
                         return Err(anyhow::format_err!(
                             "Failed to delete {} objects",
                             errors.len()

pageserver/src/deletion_queue.rs

@@ -153,7 +153,7 @@ impl FlushOp {
 
 #[derive(Clone, Debug)]
 pub struct DeletionQueueClient {
-    tx: tokio::sync::mpsc::Sender<ListWriterQueueMessage>,
+    tx: tokio::sync::mpsc::UnboundedSender<ListWriterQueueMessage>,
     executor_tx: tokio::sync::mpsc::Sender<DeleterMessage>,
 
     lsn_table: Arc<std::sync::RwLock<VisibleLsnUpdates>>,
@@ -416,7 +416,7 @@ pub enum DeletionQueueError {
 impl DeletionQueueClient {
     pub(crate) fn broken() -> Self {
         // Channels whose receivers are immediately dropped.
-        let (tx, _rx) = tokio::sync::mpsc::channel(1);
+        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
         let (executor_tx, _executor_rx) = tokio::sync::mpsc::channel(1);
         Self {
             tx,
@@ -428,12 +428,12 @@ impl DeletionQueueClient {
     /// This is cancel-safe.  If you drop the future before it completes, the message
     /// is not pushed, although in the context of the deletion queue it doesn't matter: once
     /// we decide to do a deletion the decision is always final.
-    async fn do_push<T>(
+    fn do_push<T>(
         &self,
-        queue: &tokio::sync::mpsc::Sender<T>,
+        queue: &tokio::sync::mpsc::UnboundedSender<T>,
         msg: T,
     ) -> Result<(), DeletionQueueError> {
-        match queue.send(msg).await {
+        match queue.send(msg) {
             Ok(_) => Ok(()),
             Err(e) => {
                 // This shouldn't happen, we should shut down all tenants before
@@ -445,7 +445,7 @@ impl DeletionQueueClient {
         }
     }
 
-    pub(crate) async fn recover(
+    pub(crate) fn recover(
         &self,
         attached_tenants: HashMap<TenantId, Generation>,
     ) -> Result<(), DeletionQueueError> {
@@ -453,7 +453,6 @@ impl DeletionQueueClient {
             &self.tx,
             ListWriterQueueMessage::Recover(RecoverOp { attached_tenants }),
         )
-        .await
     }
 
     /// When a Timeline wishes to update the remote_consistent_lsn that it exposes to the outside
@@ -526,6 +525,21 @@ impl DeletionQueueClient {
             return self.flush_immediate().await;
         }
 
+        self.push_layers_sync(tenant_id, timeline_id, current_generation, layers)
+    }
+
+    /// When a Tenant has a generation, push_layers is always synchronous because
+    /// the ListValidator channel is an unbounded channel.
+    ///
+    /// This can be merged into push_layers when we remove the Generation-less mode
+    /// support (`<https://github.com/neondatabase/neon/issues/5395>`)
+    pub(crate) fn push_layers_sync(
+        &self,
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+        current_generation: Generation,
+        layers: Vec<(LayerFileName, Generation)>,
+    ) -> Result<(), DeletionQueueError> {
         metrics::DELETION_QUEUE
             .keys_submitted
             .inc_by(layers.len() as u64);
@@ -539,17 +553,16 @@ impl DeletionQueueClient {
                 objects: Vec::new(),
             }),
         )
-        .await
     }
 
     /// This is cancel-safe.  If you drop the future the flush may still happen in the background.
     async fn do_flush<T>(
         &self,
-        queue: &tokio::sync::mpsc::Sender<T>,
+        queue: &tokio::sync::mpsc::UnboundedSender<T>,
         msg: T,
         rx: tokio::sync::oneshot::Receiver<()>,
     ) -> Result<(), DeletionQueueError> {
-        self.do_push(queue, msg).await?;
+        self.do_push(queue, msg)?;
         if rx.await.is_err() {
             // This shouldn't happen if tenants are shut down before deletion queue.  If we
             // encounter a bug like this, then a flusher will incorrectly believe it has flushed
@@ -570,6 +583,18 @@ impl DeletionQueueClient {
             .await
     }
 
+    /// Issue a flush without waiting for it to complete.  This is useful on advisory flushes where
+    /// the caller wants to avoid the risk of waiting for lots of enqueued work, such as on tenant
+    /// detach where flushing is nice but not necessary.
+    ///
+    /// This function provides no guarantees of work being done.
+    pub fn flush_advisory(&self) {
+        let (flush_op, _) = FlushOp::new();
+
+        // Transmit the flush message, ignoring any result (such as a closed channel during shutdown).
+        drop(self.tx.send(ListWriterQueueMessage::FlushExecute(flush_op)));
+    }
+
     // Wait until all previous deletions are executed
     pub(crate) async fn flush_execute(&self) -> Result<(), DeletionQueueError> {
         debug!("flush_execute: flushing to deletion lists...");
@@ -586,9 +611,7 @@ impl DeletionQueueClient {
         // Flush any immediate-mode deletions (the above backend flush will only flush
         // the executor if deletions had flowed through the backend)
         debug!("flush_execute: flushing execution...");
-        let (flush_op, rx) = FlushOp::new();
-        self.do_flush(&self.executor_tx, DeleterMessage::Flush(flush_op), rx)
-            .await?;
+        self.flush_immediate().await?;
         debug!("flush_execute: finished flushing execution...");
         Ok(())
     }
@@ -643,8 +666,10 @@ impl DeletionQueue {
     where
         C: ControlPlaneGenerationsApi + Send + Sync,
     {
-        // Deep channel: it consumes deletions from all timelines and we do not want to block them
-        let (tx, rx) = tokio::sync::mpsc::channel(16384);
+        // Unbounded channel: enables non-async functions to submit deletions.  The actual length is
+        // constrained by how promptly the ListWriter wakes up and drains it, which should be frequent
+        // enough to avoid this taking pathologically large amount of memory.
+        let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
 
         // Shallow channel: it carries DeletionLists which each contain up to thousands of deletions
         let (backend_tx, backend_rx) = tokio::sync::mpsc::channel(16);
@@ -957,7 +982,7 @@ mod test {
         // Basic test that the deletion queue processes the deletions we pass into it
         let ctx = setup("deletion_queue_smoke").expect("Failed test setup");
         let client = ctx.deletion_queue.new_client();
-        client.recover(HashMap::new()).await?;
+        client.recover(HashMap::new())?;
 
         let layer_file_name_1: LayerFileName = "000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000016B59D8-00000000016B5A51".parse().unwrap();
         let tenant_id = ctx.harness.tenant_id;
@@ -1025,7 +1050,7 @@ mod test {
     async fn deletion_queue_validation() -> anyhow::Result<()> {
         let ctx = setup("deletion_queue_validation").expect("Failed test setup");
         let client = ctx.deletion_queue.new_client();
-        client.recover(HashMap::new()).await?;
+        client.recover(HashMap::new())?;
 
         // Generation that the control plane thinks is current
         let latest_generation = Generation::new(0xdeadbeef);
@@ -1082,7 +1107,7 @@ mod test {
         // Basic test that the deletion queue processes the deletions we pass into it
         let mut ctx = setup("deletion_queue_recovery").expect("Failed test setup");
         let client = ctx.deletion_queue.new_client();
-        client.recover(HashMap::new()).await?;
+        client.recover(HashMap::new())?;
 
         let tenant_id = ctx.harness.tenant_id;
 
@@ -1145,9 +1170,7 @@ mod test {
         drop(client);
         ctx.restart().await;
         let client = ctx.deletion_queue.new_client();
-        client
-            .recover(HashMap::from([(tenant_id, now_generation)]))
-            .await?;
+        client.recover(HashMap::from([(tenant_id, now_generation)]))?;
 
         info!("Flush-executing");
         client.flush_execute().await?;
@@ -1173,7 +1196,7 @@ pub(crate) mod mock {
     };
 
     pub struct ConsumerState {
-        rx: tokio::sync::mpsc::Receiver<ListWriterQueueMessage>,
+        rx: tokio::sync::mpsc::UnboundedReceiver<ListWriterQueueMessage>,
         executor_rx: tokio::sync::mpsc::Receiver<DeleterMessage>,
     }
 
@@ -1250,7 +1273,7 @@ pub(crate) mod mock {
     }
 
     pub struct MockDeletionQueue {
-        tx: tokio::sync::mpsc::Sender<ListWriterQueueMessage>,
+        tx: tokio::sync::mpsc::UnboundedSender<ListWriterQueueMessage>,
         executor_tx: tokio::sync::mpsc::Sender<DeleterMessage>,
         executed: Arc<AtomicUsize>,
         remote_storage: Option<GenericRemoteStorage>,
@@ -1260,7 +1283,7 @@ pub(crate) mod mock {
 
     impl MockDeletionQueue {
         pub fn new(remote_storage: Option<GenericRemoteStorage>) -> Self {
-            let (tx, rx) = tokio::sync::mpsc::channel(16384);
+            let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
             let (executor_tx, executor_rx) = tokio::sync::mpsc::channel(16384);
 
             let executed = Arc::new(AtomicUsize::new(0));

pageserver/src/deletion_queue/deleter.rs

@@ -13,6 +13,7 @@ use std::time::Duration;
 use tokio_util::sync::CancellationToken;
 use tracing::info;
 use tracing::warn;
+use utils::backoff;
 
 use crate::metrics;
 
@@ -63,7 +64,19 @@ impl Deleter {
             Err(anyhow::anyhow!("failpoint hit"))
         });
 
-        self.remote_storage.delete_objects(&self.accumulator).await
+        // A backoff::retry is used here for two reasons:
+        // - To provide a backoff rather than busy-polling the API on errors
+        // - To absorb transient 429/503 conditions without hitting our error
+        //   logging path for issues deleting objects.
+        backoff::retry(
+            || async { self.remote_storage.delete_objects(&self.accumulator).await },
+            |_| false,
+            3,
+            10,
+            "executing deletion batch",
+            backoff::Cancel::new(self.cancel.clone(), || anyhow::anyhow!("Shutting down")),
+        )
+        .await
     }
 
     /// Block until everything in accumulator has been executed
@@ -88,7 +101,10 @@ impl Deleter {
                     self.accumulator.clear();
                 }
                 Err(e) => {
-                    warn!("DeleteObjects request failed: {e:#}, will retry");
+                    if self.cancel.is_cancelled() {
+                        return Err(DeletionQueueError::ShuttingDown);
+                    }
+                    warn!("DeleteObjects request failed: {e:#}, will continue trying");
                     metrics::DELETION_QUEUE
                         .remote_errors
                         .with_label_values(&["execute"])

pageserver/src/deletion_queue/list_writer.rs

@@ -85,7 +85,7 @@ pub(super) struct ListWriter {
     conf: &'static PageServerConf,
 
     // Incoming frontend requests to delete some keys
-    rx: tokio::sync::mpsc::Receiver<ListWriterQueueMessage>,
+    rx: tokio::sync::mpsc::UnboundedReceiver<ListWriterQueueMessage>,
 
     // Outbound requests to the backend to execute deletion lists we have composed.
     tx: tokio::sync::mpsc::Sender<ValidatorQueueMessage>,
@@ -111,7 +111,7 @@ impl ListWriter {
 
     pub(super) fn new(
         conf: &'static PageServerConf,
-        rx: tokio::sync::mpsc::Receiver<ListWriterQueueMessage>,
+        rx: tokio::sync::mpsc::UnboundedReceiver<ListWriterQueueMessage>,
         tx: tokio::sync::mpsc::Sender<ValidatorQueueMessage>,
         cancel: CancellationToken,
     ) -> Self {

pageserver/src/http/routes.rs

@@ -77,7 +77,7 @@ impl State {
         disk_usage_eviction_state: Arc<disk_usage_eviction_task::State>,
         deletion_queue_client: DeletionQueueClient,
     ) -> anyhow::Result<Self> {
-        let allowlist_routes = ["/v1/status", "/v1/doc", "/swagger.yml"]
+        let allowlist_routes = ["/v1/status", "/v1/doc", "/swagger.yml", "/metrics"]
             .iter()
             .map(|v| v.parse().unwrap())
             .collect::<Vec<_>>();
@@ -164,9 +164,6 @@ impl From<TenantStateError> for ApiError {
     fn from(tse: TenantStateError) -> ApiError {
         match tse {
             TenantStateError::NotFound(tid) => ApiError::NotFound(anyhow!("tenant {}", tid).into()),
-            TenantStateError::NotActive(_) => {
-                ApiError::ResourceUnavailable("Tenant not yet active".into())
-            }
             TenantStateError::IsStopping(_) => {
                 ApiError::ResourceUnavailable("Tenant is stopping".into())
             }
@@ -575,9 +572,14 @@ async fn tenant_detach_handler(
 
     let state = get_state(&request);
     let conf = state.conf;
-    mgr::detach_tenant(conf, tenant_id, detach_ignored.unwrap_or(false))
-        .instrument(info_span!("tenant_detach", %tenant_id))
-        .await?;
+    mgr::detach_tenant(
+        conf,
+        tenant_id,
+        detach_ignored.unwrap_or(false),
+        &state.deletion_queue_client,
+    )
+    .instrument(info_span!("tenant_detach", %tenant_id))
+    .await?;
 
     json_response(StatusCode::OK, ())
 }
@@ -1034,7 +1036,7 @@ async fn put_tenant_location_config_handler(
     // The `Detached` state is special, it doesn't upsert a tenant, it removes
     // its local disk content and drops it from memory.
     if let LocationConfigMode::Detached = request_data.config.mode {
-        mgr::detach_tenant(conf, tenant_id, true)
+        mgr::detach_tenant(conf, tenant_id, true, &state.deletion_queue_client)
             .instrument(info_span!("tenant_detach", %tenant_id))
             .await?;
         return json_response(StatusCode::OK, ());

pageserver/src/tenant.rs

@@ -29,11 +29,11 @@ use std::cmp::min;
 use std::collections::hash_map::Entry;
 use std::collections::BTreeSet;
 use std::collections::HashMap;
+use std::collections::HashSet;
 use std::fmt::Debug;
 use std::fmt::Display;
 use std::fs;
 use std::fs::File;
-use std::io;
 use std::ops::Bound::Included;
 use std::process::Command;
 use std::process::Stdio;
@@ -45,10 +45,10 @@ use std::sync::{Mutex, RwLock};
 use std::time::{Duration, Instant};
 
 use self::config::AttachedLocationConfig;
+use self::config::AttachmentMode;
 use self::config::LocationConf;
 use self::config::TenantConf;
 use self::delete::DeleteTenantFlow;
-use self::metadata::LoadMetadataError;
 use self::metadata::TimelineMetadata;
 use self::mgr::TenantsMap;
 use self::remote_timeline_client::RemoteTimelineClient;
@@ -208,7 +208,7 @@ pub struct Tenant {
 
     /// The remote storage generation, used to protect S3 objects from split-brain.
     /// Does not change over the lifetime of the [`Tenant`] object.
-    ///  
+    ///
     /// This duplicates the generation stored in LocationConf, but that structure is mutable:
     /// this copy enforces the invariant that generatio doesn't change during a Tenant's lifetime.
     generation: Generation,
@@ -372,6 +372,13 @@ struct RemoteStartupData {
     remote_metadata: TimelineMetadata,
 }
 
+struct TimelinePreload {
+    timeline_id: TimelineId,
+    remote_client: Option<RemoteTimelineClient>,
+    index_part: Option<IndexPart>,
+    metadata: TimelineMetadata,
+}
+
 #[derive(Debug, thiserror::Error)]
 pub(crate) enum WaitToBecomeActiveError {
     WillNotBecomeActive {
@@ -412,11 +419,6 @@ pub enum CreateTimelineError {
     Other(#[from] anyhow::Error),
 }
 
-struct TenantDirectoryScan {
-    sorted_timelines_to_load: Vec<(TimelineId, TimelineMetadata)>,
-    timelines_to_resume_deletion: Vec<(TimelineId, Option<TimelineMetadata>)>,
-}
-
 enum CreateTimelineCause {
     Load,
     Delete,
@@ -660,41 +662,14 @@ impl Tenant {
         Ok(tenant)
     }
 
-    ///
-    /// Background task that downloads all data for a tenant and brings it to Active state.
-    ///
-    /// No background tasks are started as part of this routine.
-    ///
-    async fn attach(self: &Arc<Tenant>, ctx: &RequestContext) -> anyhow::Result<()> {
-        span::debug_assert_current_span_has_tenant_id();
-
-        let marker_file = self.conf.tenant_attaching_mark_file_path(&self.tenant_id);
-        if !tokio::fs::try_exists(&marker_file)
-            .await
-            .context("check for existence of marker file")?
-        {
-            anyhow::bail!(
-                "implementation error: marker file should exist at beginning of this function"
-            );
-        }
-
-        // Get list of remote timelines
-        // download index files for every tenant timeline
-        info!("listing remote timelines");
-
-        let remote_storage = self
-            .remote_storage
-            .as_ref()
-            .ok_or_else(|| anyhow::anyhow!("cannot attach without remote storage"))?;
-
-        let remote_timeline_ids =
-            remote_timeline_client::list_remote_timelines(remote_storage, self.tenant_id).await?;
-
-        info!("found {} timelines", remote_timeline_ids.len());
-
-        // Download & parse index parts
+    fn download_indices(
+        &self,
+        timeline_ids: HashSet<TimelineId>,
+        remote_storage: &GenericRemoteStorage,
+    ) -> JoinSet<Result<(TimelineId, RemoteTimelineClient, MaybeDeletedIndexPart), anyhow::Error>>
+    {
         let mut part_downloads = JoinSet::new();
-        for timeline_id in remote_timeline_ids {
+        for timeline_id in timeline_ids {
             let client = RemoteTimelineClient::new(
                 remote_storage.clone(),
                 self.deletion_queue_client.clone(),
@@ -723,11 +698,56 @@ impl Tenant {
             );
         }
 
+        part_downloads
+    }
+
+    /// Special variant of preload_timelines that does not rely on remote storage
+    async fn preload_timelines_local(
+        self: &Arc<Self>,
+        timeline_ids: &HashSet<TimelineId>,
+    ) -> anyhow::Result<Vec<TimelinePreload>> {
+        let mut preload_map = HashMap::new();
+        for timeline_id in timeline_ids {
+            let metadata = load_metadata(self.conf, &self.tenant_id, timeline_id)?;
+            preload_map.insert(
+                *timeline_id,
+                TimelinePreload {
+                    timeline_id: *timeline_id,
+                    remote_client: None,
+                    // TODO: synthesize an index_part and make it non-optional
+                    index_part: None,
+                    metadata,
+                },
+            );
+        }
+
+        // Sort by ancestry
+        Ok(
+            tree_sort_timelines(preload_map, |p| p.metadata.ancestor_timeline())?
+                .into_iter()
+                .map(|i| i.1)
+                .collect(),
+        )
+    }
+
+    /// Do the remote I/O and sorting required to prepare a list of timelines
+    /// with their IndexParts, ready for hydrating into `Timeline`
+    async fn preload_timelines(
+        self: &Arc<Self>,
+        timeline_ids: HashSet<TimelineId>,
+        remote_storage: &GenericRemoteStorage,
+    ) -> anyhow::Result<Vec<TimelinePreload>> {
+        span::debug_assert_current_span_has_tenant_id();
+
+        let mut part_downloads = self.download_indices(timeline_ids, remote_storage);
+
         let mut timelines_to_resume_deletions = vec![];
 
+        // We construct a map all timeline's preload state, prior to sorting
+        // it by ancestry at the end of the function
+        let mut preload_map: HashMap<TimelineId, TimelinePreload> = HashMap::new();
+
         // Wait for all the download tasks to complete & collect results.
-        let mut remote_index_and_client = HashMap::new();
-        let mut timeline_ancestors = HashMap::new();
         while let Some(result) = part_downloads.join_next().await {
             // NB: we already added timeline_id as context to the error
             let result: Result<_, anyhow::Error> = result.context("joinset task join")?;
@@ -735,8 +755,16 @@ impl Tenant {
             debug!("successfully downloaded index part for timeline {timeline_id}");
             match index_part {
                 MaybeDeletedIndexPart::IndexPart(index_part) => {
-                    timeline_ancestors.insert(timeline_id, index_part.metadata.clone());
-                    remote_index_and_client.insert(timeline_id, (index_part, client));
+                    let metadata = index_part.metadata.clone();
+                    preload_map.insert(
+                        timeline_id,
+                        TimelinePreload {
+                            timeline_id,
+                            remote_client: Some(client),
+                            index_part: Some(index_part),
+                            metadata,
+                        },
+                    );
                 }
                 MaybeDeletedIndexPart::Deleted(index_part) => {
                     info!(
@@ -748,35 +776,6 @@ impl Tenant {
             }
         }
 
-        // For every timeline, download the metadata file, scan the local directory,
-        // and build a layer map that contains an entry for each remote and local
-        // layer file.
-        let sorted_timelines = tree_sort_timelines(timeline_ancestors, |m| m.ancestor_timeline())?;
-        for (timeline_id, remote_metadata) in sorted_timelines {
-            let (index_part, remote_client) = remote_index_and_client
-                .remove(&timeline_id)
-                .expect("just put it in above");
-
-            // TODO again handle early failure
-            self.load_remote_timeline(
-                timeline_id,
-                index_part,
-                remote_metadata,
-                TimelineResources {
-                    remote_client: Some(remote_client),
-                    deletion_queue_client: self.deletion_queue_client.clone(),
-                },
-                ctx,
-            )
-            .await
-            .with_context(|| {
-                format!(
-                    "failed to load remote timeline {} for tenant {}",
-                    timeline_id, self.tenant_id
-                )
-            })?;
-        }
-
         // Walk through deleted timelines, resume deletion
         for (timeline_id, index_part, remote_timeline_client) in timelines_to_resume_deletions {
             remote_timeline_client
@@ -797,6 +796,81 @@ impl Tenant {
             .map_err(LoadLocalTimelineError::ResumeDeletion)?;
         }
 
+        // Sort by ancestry
+        Ok(
+            tree_sort_timelines(preload_map, |p| p.metadata.ancestor_timeline())?
+                .into_iter()
+                .map(|i| i.1)
+                .collect(),
+        )
+    }
+
+    ///
+    /// Background task that downloads all data for a tenant and brings it to Active state.
+    ///
+    /// No background tasks are started as part of this routine.
+    ///
+    async fn attach(self: &Arc<Tenant>, ctx: &RequestContext) -> anyhow::Result<()> {
+        span::debug_assert_current_span_has_tenant_id();
+
+        let marker_file = self.conf.tenant_attaching_mark_file_path(&self.tenant_id);
+        if !tokio::fs::try_exists(&marker_file)
+            .await
+            .context("check for existence of marker file")?
+        {
+            anyhow::bail!(
+                "implementation error: marker file should exist at beginning of this function"
+            );
+        }
+
+        // Get list of remote timelines
+        info!("listing remote timelines");
+
+        let remote_storage = self
+            .remote_storage
+            .as_ref()
+            .ok_or_else(|| anyhow::anyhow!("cannot attach without remote storage"))?;
+
+        let remote_timeline_ids =
+            remote_timeline_client::list_remote_timelines(remote_storage, self.tenant_id).await?;
+
+        info!("found {} timelines", remote_timeline_ids.len());
+
+        // Download & parse index parts
+        let sorted_timelines = self
+            .preload_timelines(remote_timeline_ids, remote_storage)
+            .await?;
+
+        // For every timeline, download the metadata file, scan the local directory,
+        // and build a layer map that contains an entry for each remote and local
+        // layer file.
+        for timeline_preload in sorted_timelines {
+            let TimelinePreload {
+                timeline_id,
+                remote_client,
+                index_part,
+                metadata: _,
+            } = timeline_preload;
+
+            // TODO again handle early failure
+            self.load_remote_timeline(
+                timeline_id,
+                index_part.unwrap(),
+                TimelineResources {
+                    remote_client,
+                    deletion_queue_client: self.deletion_queue_client.clone(),
+                },
+                ctx,
+            )
+            .await
+            .with_context(|| {
+                format!(
+                    "failed to load remote timeline {} for tenant {}",
+                    timeline_id, self.tenant_id
+                )
+            })?;
+        }
+
         std::fs::remove_file(&marker_file)
             .with_context(|| format!("unlink attach marker file {marker_file}"))?;
         crashsafe::fsync(marker_file.parent().expect("marker file has parent dir"))
@@ -829,7 +903,6 @@ impl Tenant {
         &self,
         timeline_id: TimelineId,
         index_part: IndexPart,
-        remote_metadata: TimelineMetadata,
         resources: TimelineResources,
         ctx: &RequestContext,
     ) -> anyhow::Result<()> {
@@ -840,7 +913,7 @@ impl Tenant {
             .await
             .context("Failed to create new timeline directory")?;
 
-        let ancestor = if let Some(ancestor_id) = remote_metadata.ancestor_timeline() {
+        let ancestor = if let Some(ancestor_id) = index_part.metadata.ancestor_timeline() {
             let timelines = self.timelines.lock().unwrap();
             Some(Arc::clone(timelines.get(&ancestor_id).ok_or_else(
                 || {
@@ -858,6 +931,7 @@ impl Tenant {
         // cannot be older than the local one
         let local_metadata = None;
 
+        let remote_metadata = index_part.metadata.clone();
         self.timeline_init_and_sync(
             timeline_id,
             resources,
@@ -1031,12 +1105,9 @@ impl Tenant {
         tenant
     }
 
-    fn scan_and_sort_timelines_dir(self: Arc<Tenant>) -> anyhow::Result<TenantDirectoryScan> {
-        let mut timelines_to_load: HashMap<TimelineId, TimelineMetadata> = HashMap::new();
-        // Note timelines_to_resume_deletion needs to be separate because it can be not sortable
-        // from the point of `tree_sort_timelines`. I e some parents can be missing because deletion
-        // completed in non topological order (for example because parent has smaller number of layer files in it)
-        let mut timelines_to_resume_deletion: Vec<(TimelineId, Option<TimelineMetadata>)> = vec![];
+    async fn scan_timelines_dir(self: &Arc<Tenant>) -> anyhow::Result<HashSet<TimelineId>> {
+        let mut timelines_to_load: HashSet<TimelineId> = HashSet::new();
+        let mut timelines_to_resume_deletion: HashSet<TimelineId> = HashSet::new();
 
         let timelines_dir = self.conf.timelines_path(&self.tenant_id);
 
@@ -1085,38 +1156,7 @@ impl Tenant {
                     })?;
 
                 info!("Found deletion mark for timeline {}", timeline_id);
-
-                match load_metadata(self.conf, &self.tenant_id, &timeline_id) {
-                    Ok(metadata) => {
-                        timelines_to_resume_deletion.push((timeline_id, Some(metadata)))
-                    }
-                    Err(e) => match &e {
-                        LoadMetadataError::Read(r) => {
-                            if r.kind() != io::ErrorKind::NotFound {
-                                return Err(anyhow::anyhow!(e)).with_context(|| {
-                                    format!("Failed to load metadata for timeline_id {timeline_id}")
-                                });
-                            }
-
-                            // If metadata doesnt exist it means that we've crashed without
-                            // completing cleanup_remaining_timeline_fs_traces in DeleteTimelineFlow.
-                            // So save timeline_id for later call to `DeleteTimelineFlow::cleanup_remaining_timeline_fs_traces`.
-                            // We cant do it here because the method is async so we'd need block_on
-                            // and here we're in spawn_blocking. cleanup_remaining_timeline_fs_traces uses fs operations
-                            // so that basically results in a cycle:
-                            // spawn_blocking
-                            // - block_on
-                            //   - spawn_blocking
-                            // which can lead to running out of threads in blocing pool.
-                            timelines_to_resume_deletion.push((timeline_id, None));
-                        }
-                        _ => {
-                            return Err(anyhow::anyhow!(e)).with_context(|| {
-                                format!("Failed to load metadata for timeline_id {timeline_id}")
-                            })
-                        }
-                    },
-                }
+                timelines_to_resume_deletion.insert(timeline_id);
             } else {
                 if !timeline_dir.exists() {
                     warn!("Timeline dir entry become invalid: {timeline_dir}");
@@ -1154,9 +1194,7 @@ impl Tenant {
 
                 let file_name = entry.file_name();
                 if let Ok(timeline_id) = file_name.parse::<TimelineId>() {
-                    let metadata = load_metadata(self.conf, &self.tenant_id, &timeline_id)
-                        .context("failed to load metadata")?;
-                    timelines_to_load.insert(timeline_id, metadata);
+                    timelines_to_load.insert(timeline_id);
                 } else {
                     // A file or directory that doesn't look like a timeline ID
                     warn!("unexpected file or directory in timelines directory: {file_name}");
@@ -1164,14 +1202,18 @@ impl Tenant {
             }
         }
 
-        // Sort the array of timeline IDs into tree-order, so that parent comes before
-        // all its children.
-        tree_sort_timelines(timelines_to_load, |m| m.ancestor_timeline()).map(|sorted_timelines| {
-            TenantDirectoryScan {
-                sorted_timelines_to_load: sorted_timelines,
-                timelines_to_resume_deletion,
+        for timeline_id in timelines_to_resume_deletion {
+            if let Err(e) =
+                DeleteTimelineFlow::cleanup_remaining_timeline_fs_traces(self, timeline_id).await
+            {
+                warn!(
+                    "cannot clean up deleted timeline dir timeline_id: {} error: {:#}",
+                    timeline_id, e
+                );
             }
-        })
+        }
+
+        Ok(timelines_to_load)
     }
 
     ///
@@ -1194,24 +1236,34 @@ impl Tenant {
         //
         // Scan the directory, peek into the metadata file of each timeline, and
         // collect a list of timelines and their ancestors.
-        let span = info_span!("blocking");
         let cloned = Arc::clone(self);
 
-        let scan = tokio::task::spawn_blocking(move || {
-            let _g = span.entered();
-            cloned.scan_and_sort_timelines_dir()
-        })
-        .await
-        .context("load spawn_blocking")
-        .and_then(|res| res)?;
+        let local_timelines = tokio::task::spawn(async move { cloned.scan_timelines_dir().await })
+            .await
+            .context("load spawn_blocking")
+            .and_then(|res| res)?;
 
-        // FIXME original collect_timeline_files contained one more check:
-        //    1. "Timeline has no ancestor and no layer files"
+        let sorted_timelines = match &self.remote_storage {
+            Some(remote_storage) => {
+                self.preload_timelines(local_timelines, remote_storage)
+                    .await?
+            }
+            None => {
+                // Deprecated mode, only used in dev.
+                self.preload_timelines_local(&local_timelines).await?
+            }
+        };
+
+        for timeline_preload in sorted_timelines {
+            let TimelinePreload {
+                timeline_id,
+                remote_client: _,
+                index_part: _,
+                metadata,
+            } = timeline_preload;
 
-        // Process loadable timelines first
-        for (timeline_id, local_metadata) in scan.sorted_timelines_to_load {
             if let Err(e) = self
-                .load_local_timeline(timeline_id, local_metadata, init_order, ctx, false)
+                .load_local_timeline(timeline_id, metadata, init_order, ctx, false)
                 .await
             {
                 match e {
@@ -1228,43 +1280,6 @@ impl Tenant {
             }
         }
 
-        // Resume deletion ones with deleted_mark
-        for (timeline_id, maybe_local_metadata) in scan.timelines_to_resume_deletion {
-            match maybe_local_metadata {
-                None => {
-                    // See comment in `scan_and_sort_timelines_dir`.
-                    if let Err(e) =
-                        DeleteTimelineFlow::cleanup_remaining_timeline_fs_traces(self, timeline_id)
-                            .await
-                    {
-                        warn!(
-                            "cannot clean up deleted timeline dir timeline_id: {} error: {:#}",
-                            timeline_id, e
-                        );
-                    }
-                }
-                Some(local_metadata) => {
-                    if let Err(e) = self
-                        .load_local_timeline(timeline_id, local_metadata, init_order, ctx, true)
-                        .await
-                    {
-                        match e {
-                            LoadLocalTimelineError::Load(source) => {
-                                // We tried to load deleted timeline, this is a bug.
-                                return Err(anyhow::anyhow!(source).context(
-                                "This is a bug. We tried to load deleted timeline which is wrong and loading failed. Timeline: {timeline_id}"
-                            ));
-                            }
-                            LoadLocalTimelineError::ResumeDeletion(source) => {
-                                // Make sure resumed deletion wont fail loading for entire tenant.
-                                error!("Failed to resume timeline deletion: {source:#}")
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
         trace!("Done");
 
         Ok(())
@@ -2076,6 +2091,15 @@ impl Tenant {
             }
         }
     }
+
+    pub(crate) fn get_attach_mode(&self) -> AttachmentMode {
+        self.tenant_conf
+            .read()
+            .unwrap()
+            .location
+            .attach_mode
+            .clone()
+    }
 }
 
 /// Given a Vec of timelines and their ancestors (timeline_id, ancestor_id),
@@ -2745,6 +2769,11 @@ impl Tenant {
     ) -> 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.
+        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
         let start_lsn = start_lsn.unwrap_or_else(|| {
             let lsn = src_timeline.get_last_record_lsn();
@@ -2752,11 +2781,6 @@ impl Tenant {
             lsn
         });
 
-        // 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.
-        let _gc_cs = self.gc_cs.lock().await;
-
         // Create a placeholder for the new branch. This will error
         // out if the new timeline ID is already in use.
         let timeline_uninit_mark = {

pageserver/src/tenant/delete.rs

@@ -31,7 +31,7 @@ use super::{
 const SHOULD_RESUME_DELETION_FETCH_MARK_ATTEMPTS: u32 = 3;
 
 #[derive(Debug, thiserror::Error)]
-pub enum DeleteTenantError {
+pub(crate) enum DeleteTenantError {
     #[error("GetTenant {0}")]
     Get(#[from] GetTenantError),
 
@@ -376,7 +376,7 @@ impl DeleteTenantFlow {
         Ok(())
     }
 
-    pub async fn should_resume_deletion(
+    pub(crate) async fn should_resume_deletion(
         conf: &'static PageServerConf,
         remote_storage: Option<&GenericRemoteStorage>,
         tenant: &Tenant,

pageserver/src/tenant/mgr.rs

@@ -24,7 +24,7 @@ use crate::control_plane_client::{
 };
 use crate::deletion_queue::DeletionQueueClient;
 use crate::task_mgr::{self, TaskKind};
-use crate::tenant::config::{LocationConf, LocationMode, TenantConfOpt};
+use crate::tenant::config::{AttachmentMode, LocationConf, LocationMode, TenantConfOpt};
 use crate::tenant::delete::DeleteTenantFlow;
 use crate::tenant::{
     create_tenant_files, AttachedTenantConf, CreateTenantFilesMode, Tenant, TenantState,
@@ -50,7 +50,7 @@ use super::TenantSharedResources;
 /// its lifetime, and we can preserve some important safety invariants like `Tenant` always
 /// having a properly acquired generation (Secondary doesn't need a generation)
 #[derive(Clone)]
-pub enum TenantSlot {
+pub(crate) enum TenantSlot {
     Attached(Arc<Tenant>),
     Secondary,
 }
@@ -206,8 +206,7 @@ async fn init_load_generations(
     if resources.remote_storage.is_some() {
         resources
             .deletion_queue_client
-            .recover(generations.clone())
-            .await?;
+            .recover(generations.clone())?;
     }
 
     Ok(Some(generations))
@@ -482,7 +481,7 @@ pub(crate) fn schedule_local_tenant_processing(
 /// management API. For example, it could attach the tenant on a different pageserver.
 /// We would then be in split-brain once this pageserver restarts.
 #[instrument(skip_all)]
-pub async fn shutdown_all_tenants() {
+pub(crate) async fn shutdown_all_tenants() {
     shutdown_all_tenants0(&TENANTS).await
 }
 
@@ -594,7 +593,7 @@ async fn shutdown_all_tenants0(tenants: &tokio::sync::RwLock<TenantsMap>) {
     // caller will log how long we took
 }
 
-pub async fn create_tenant(
+pub(crate) async fn create_tenant(
     conf: &'static PageServerConf,
     tenant_conf: TenantConfOpt,
     tenant_id: TenantId,
@@ -629,14 +628,14 @@ pub async fn create_tenant(
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum SetNewTenantConfigError {
+pub(crate) enum SetNewTenantConfigError {
     #[error(transparent)]
     GetTenant(#[from] GetTenantError),
     #[error(transparent)]
     Persist(anyhow::Error),
 }
 
-pub async fn set_new_tenant_config(
+pub(crate) async fn set_new_tenant_config(
     conf: &'static PageServerConf,
     new_tenant_conf: TenantConfOpt,
     tenant_id: TenantId,
@@ -695,6 +694,18 @@ pub(crate) async fn upsert_location(
 
     if let Some(tenant) = shutdown_tenant {
         let (_guard, progress) = utils::completion::channel();
+
+        match tenant.get_attach_mode() {
+            AttachmentMode::Single | AttachmentMode::Multi => {
+                // Before we leave our state as the presumed holder of the latest generation,
+                // flush any outstanding deletions to reduce the risk of leaking objects.
+                deletion_queue_client.flush_advisory()
+            }
+            AttachmentMode::Stale => {
+                // If we're stale there's not point trying to flush deletions
+            }
+        };
+
         info!("Shutting down attached tenant");
         match tenant.shutdown(progress, false).await {
             Ok(()) => {}
@@ -765,7 +776,7 @@ pub(crate) async fn upsert_location(
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum GetTenantError {
+pub(crate) enum GetTenantError {
     #[error("Tenant {0} not found")]
     NotFound(TenantId),
     #[error("Tenant {0} is not active")]
@@ -781,7 +792,7 @@ pub enum GetTenantError {
 /// `active_only = true` allows to query only tenants that are ready for operations, erroring on other kinds of tenants.
 ///
 /// This method is cancel-safe.
-pub async fn get_tenant(
+pub(crate) async fn get_tenant(
     tenant_id: TenantId,
     active_only: bool,
 ) -> Result<Arc<Tenant>, GetTenantError> {
@@ -806,7 +817,7 @@ pub async fn get_tenant(
     }
 }
 
-pub async fn delete_tenant(
+pub(crate) async fn delete_tenant(
     conf: &'static PageServerConf,
     remote_storage: Option<GenericRemoteStorage>,
     tenant_id: TenantId,
@@ -815,7 +826,7 @@ pub async fn delete_tenant(
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum DeleteTimelineError {
+pub(crate) enum DeleteTimelineError {
     #[error("Tenant {0}")]
     Tenant(#[from] GetTenantError),
 
@@ -823,7 +834,7 @@ pub enum DeleteTimelineError {
     Timeline(#[from] crate::tenant::DeleteTimelineError),
 }
 
-pub async fn delete_timeline(
+pub(crate) async fn delete_timeline(
     tenant_id: TenantId,
     timeline_id: TimelineId,
     _ctx: &RequestContext,
@@ -834,23 +845,29 @@ pub async fn delete_timeline(
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum TenantStateError {
+pub(crate) enum TenantStateError {
     #[error("Tenant {0} not found")]
     NotFound(TenantId),
     #[error("Tenant {0} is stopping")]
     IsStopping(TenantId),
-    #[error("Tenant {0} is not active")]
-    NotActive(TenantId),
     #[error(transparent)]
     Other(#[from] anyhow::Error),
 }
 
-pub async fn detach_tenant(
+pub(crate) async fn detach_tenant(
     conf: &'static PageServerConf,
     tenant_id: TenantId,
     detach_ignored: bool,
+    deletion_queue_client: &DeletionQueueClient,
 ) -> Result<(), TenantStateError> {
-    let tmp_path = detach_tenant0(conf, &TENANTS, tenant_id, detach_ignored).await?;
+    let tmp_path = detach_tenant0(
+        conf,
+        &TENANTS,
+        tenant_id,
+        detach_ignored,
+        deletion_queue_client,
+    )
+    .await?;
     // 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;
@@ -875,6 +892,7 @@ async fn detach_tenant0(
     tenants: &tokio::sync::RwLock<TenantsMap>,
     tenant_id: TenantId,
     detach_ignored: bool,
+    deletion_queue_client: &DeletionQueueClient,
 ) -> Result<Utf8PathBuf, TenantStateError> {
     let tenant_dir_rename_operation = |tenant_id_to_clean| async move {
         let local_tenant_directory = conf.tenant_path(&tenant_id_to_clean);
@@ -886,6 +904,10 @@ async fn detach_tenant0(
     let removal_result =
         remove_tenant_from_memory(tenants, tenant_id, tenant_dir_rename_operation(tenant_id)).await;
 
+    // Flush pending deletions, so that they have a good chance of passing validation
+    // before this tenant is potentially re-attached elsewhere.
+    deletion_queue_client.flush_advisory();
+
     // Ignored tenants are not present in memory and will bail the removal from memory operation.
     // Before returning the error, check for ignored tenant removal case — we only need to clean its local files then.
     if detach_ignored && matches!(removal_result, Err(TenantStateError::NotFound(_))) {
@@ -902,7 +924,7 @@ async fn detach_tenant0(
     removal_result
 }
 
-pub async fn load_tenant(
+pub(crate) async fn load_tenant(
     conf: &'static PageServerConf,
     tenant_id: TenantId,
     generation: Generation,
@@ -939,7 +961,7 @@ pub async fn load_tenant(
     Ok(())
 }
 
-pub async fn ignore_tenant(
+pub(crate) async fn ignore_tenant(
     conf: &'static PageServerConf,
     tenant_id: TenantId,
 ) -> Result<(), TenantStateError> {
@@ -967,7 +989,7 @@ async fn ignore_tenant0(
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum TenantMapListError {
+pub(crate) enum TenantMapListError {
     #[error("tenant map is still initiailizing")]
     Initializing,
 }
@@ -975,7 +997,7 @@ pub enum TenantMapListError {
 ///
 /// Get list of tenants, for the mgmt API
 ///
-pub async fn list_tenants() -> Result<Vec<(TenantId, TenantState)>, TenantMapListError> {
+pub(crate) async fn list_tenants() -> Result<Vec<(TenantId, TenantState)>, TenantMapListError> {
     let tenants = TENANTS.read().await;
     let m = match &*tenants {
         TenantsMap::Initializing => return Err(TenantMapListError::Initializing),
@@ -993,7 +1015,7 @@ pub async fn list_tenants() -> Result<Vec<(TenantId, TenantState)>, TenantMapLis
 ///
 /// Downloading all the tenant data is performed in the background, this merely
 /// spawns the background task and returns quickly.
-pub async fn attach_tenant(
+pub(crate) async fn attach_tenant(
     conf: &'static PageServerConf,
     tenant_id: TenantId,
     generation: Generation,
@@ -1030,7 +1052,7 @@ pub async fn attach_tenant(
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum TenantMapInsertError {
+pub(crate) enum TenantMapInsertError {
     #[error("tenant map is still initializing")]
     StillInitializing,
     #[error("tenant map is shutting down")]
@@ -1193,7 +1215,7 @@ use {
     utils::http::error::ApiError,
 };
 
-pub async fn immediate_gc(
+pub(crate) async fn immediate_gc(
     tenant_id: TenantId,
     timeline_id: TimelineId,
     gc_req: TimelineGcRequest,

proxy/src/bin/proxy.rs

@@ -1,5 +1,6 @@
 use futures::future::Either;
 use proxy::auth;
+use proxy::config::HttpConfig;
 use proxy::console;
 use proxy::http;
 use proxy::metrics;
@@ -79,6 +80,9 @@ struct ProxyCliArgs {
     /// Allow self-signed certificates for compute nodes (for testing)
     #[clap(long, default_value_t = false, value_parser = clap::builder::BoolishValueParser::new(), action = clap::ArgAction::Set)]
     allow_self_signed_compute: bool,
+    /// timeout for http connections
+    #[clap(long, default_value = "15s", value_parser = humantime::parse_duration)]
+    sql_over_http_timeout: tokio::time::Duration,
 }
 
 #[tokio::main]
@@ -220,12 +224,15 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
             auth::BackendType::Link(Cow::Owned(url))
         }
     };
-
+    let http_config = HttpConfig {
+        sql_over_http_timeout: args.sql_over_http_timeout,
+    };
     let config = Box::leak(Box::new(ProxyConfig {
         tls_config,
         auth_backend,
         metric_collection,
         allow_self_signed_compute: args.allow_self_signed_compute,
+        http_config,
     }));
 
     Ok(config)

proxy/src/config.rs

@@ -13,6 +13,7 @@ pub struct ProxyConfig {
     pub auth_backend: auth::BackendType<'static, ()>,
     pub metric_collection: Option<MetricCollectionConfig>,
     pub allow_self_signed_compute: bool,
+    pub http_config: HttpConfig,
 }
 
 #[derive(Debug)]
@@ -26,6 +27,10 @@ pub struct TlsConfig {
     pub common_names: Option<HashSet<String>>,
 }
 
+pub struct HttpConfig {
+    pub sql_over_http_timeout: tokio::time::Duration,
+}
+
 impl TlsConfig {
     pub fn to_server_config(&self) -> Arc<rustls::ServerConfig> {
         self.config.clone()

proxy/src/http/conn_pool.rs

@@ -20,6 +20,7 @@ use tokio_postgres::AsyncMessage;
 use crate::{
     auth, console,
     metrics::{Ids, MetricCounter, USAGE_METRICS},
+    proxy::{NUM_DB_CONNECTIONS_CLOSED_COUNTER, NUM_DB_CONNECTIONS_OPENED_COUNTER},
 };
 use crate::{compute, config};
 
@@ -418,36 +419,42 @@ async fn connect_to_compute_once(
     };
 
     tokio::spawn(
-        poll_fn(move |cx| {
-            if matches!(rx.has_changed(), Ok(true)) {
-                session = *rx.borrow_and_update();
-                info!(%session, "changed session");
+        async move {
+            NUM_DB_CONNECTIONS_OPENED_COUNTER.with_label_values(&["http"]).inc();
+            scopeguard::defer! {
+                NUM_DB_CONNECTIONS_CLOSED_COUNTER.with_label_values(&["http"]).inc();
             }
+            poll_fn(move |cx| {
+                if matches!(rx.has_changed(), Ok(true)) {
+                    session = *rx.borrow_and_update();
+                    info!(%session, "changed session");
+                }
 
-            loop {
-                let message = ready!(connection.poll_message(cx));
+                loop {
+                    let message = ready!(connection.poll_message(cx));
 
-                match message {
-                    Some(Ok(AsyncMessage::Notice(notice))) => {
-                        info!(%session, "notice: {}", notice);
-                    }
-                    Some(Ok(AsyncMessage::Notification(notif))) => {
-                        warn!(%session, pid = notif.process_id(), channel = notif.channel(), "notification received");
-                    }
-                    Some(Ok(_)) => {
-                        warn!(%session, "unknown message");
-                    }
-                    Some(Err(e)) => {
-                        error!(%session, "connection error: {}", e);
-                        return Poll::Ready(())
-                    }
-                    None => {
-                        info!("connection closed");
-                        return Poll::Ready(())
+                    match message {
+                        Some(Ok(AsyncMessage::Notice(notice))) => {
+                            info!(%session, "notice: {}", notice);
+                        }
+                        Some(Ok(AsyncMessage::Notification(notif))) => {
+                            warn!(%session, pid = notif.process_id(), channel = notif.channel(), "notification received");
+                        }
+                        Some(Ok(_)) => {
+                            warn!(%session, "unknown message");
+                        }
+                        Some(Err(e)) => {
+                            error!(%session, "connection error: {}", e);
+                            return Poll::Ready(())
+                        }
+                        None => {
+                            info!("connection closed");
+                            return Poll::Ready(())
+                        }
                     }
                 }
-            }
-        })
+            }).await
+        }
         .instrument(span)
     );
 

proxy/src/http/sql_over_http.rs

@@ -24,6 +24,9 @@ use url::Url;
 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 super::conn_pool::ConnInfo;
 use super::conn_pool::GlobalConnPool;
 
@@ -188,28 +191,46 @@ pub async fn handle(
     sni_hostname: Option<String>,
     conn_pool: Arc<GlobalConnPool>,
     session_id: uuid::Uuid,
+    config: &'static HttpConfig,
 ) -> Result<Response<Body>, ApiError> {
-    let result = handle_inner(request, sni_hostname, conn_pool, session_id).await;
-
+    let result = tokio::time::timeout(
+        config.sql_over_http_timeout,
+        handle_inner(request, sni_hostname, conn_pool, session_id),
+    )
+    .await;
     let mut response = match result {
-        Ok(r) => r,
-        Err(e) => {
-            let message = format!("{:?}", e);
-            let code = match e.downcast_ref::<tokio_postgres::Error>() {
-                Some(e) => match e.code() {
-                    Some(e) => serde_json::to_value(e.code()).unwrap(),
+        Ok(r) => match r {
+            Ok(r) => r,
+            Err(e) => {
+                let message = format!("{:?}", e);
+                let code = e.downcast_ref::<tokio_postgres::Error>().and_then(|e| {
+                    e.code()
+                        .map(|s| serde_json::to_value(s.code()).unwrap_or_default())
+                });
+                let code = match code {
+                    Some(c) => c,
                     None => Value::Null,
-                },
-                None => Value::Null,
-            };
-            error!(
-                ?code,
-                "sql-over-http per-client task finished with an error: {e:#}"
+                };
+                error!(
+                    ?code,
+                    "sql-over-http per-client task finished with an error: {e:#}"
+                );
+                // TODO: this shouldn't always be bad request.
+                json_response(
+                    StatusCode::BAD_REQUEST,
+                    json!({ "message": message, "code": code }),
+                )?
+            }
+        },
+        Err(_) => {
+            let message = format!(
+                "HTTP-Connection timed out, execution time exeeded {} seconds",
+                config.sql_over_http_timeout.as_secs()
             );
-            // TODO: this shouldn't always be bad request.
+            error!(message);
             json_response(
-                StatusCode::BAD_REQUEST,
-                json!({ "message": message, "code": code }),
+                StatusCode::GATEWAY_TIMEOUT,
+                json!({ "message": message, "code": StatusCode::GATEWAY_TIMEOUT.as_u16() }),
             )?
         }
     };
@@ -227,6 +248,13 @@ async fn handle_inner(
     conn_pool: Arc<GlobalConnPool>,
     session_id: uuid::Uuid,
 ) -> anyhow::Result<Response<Body>> {
+    NUM_CONNECTIONS_ACCEPTED_COUNTER
+        .with_label_values(&["http"])
+        .inc();
+    scopeguard::defer! {
+        NUM_CONNECTIONS_CLOSED_COUNTER.with_label_values(&["http"]).inc();
+    }
+
     //
     // Determine the destination and connection params
     //

proxy/src/http/websocket.rs

@@ -3,7 +3,10 @@ use crate::{
     config::ProxyConfig,
     error::io_error,
     protocol2::{ProxyProtocolAccept, WithClientIp},
-    proxy::{handle_client, ClientMode},
+    proxy::{
+        handle_client, ClientMode, NUM_CLIENT_CONNECTION_CLOSED_COUNTER,
+        NUM_CLIENT_CONNECTION_OPENED_COUNTER,
+    },
 };
 use bytes::{Buf, Bytes};
 use futures::{Sink, Stream, StreamExt};
@@ -202,7 +205,14 @@ async fn ws_handler(
     // TODO: that deserves a refactor as now this function also handles http json client besides websockets.
     // Right now I don't want to blow up sql-over-http patch with file renames and do that as a follow up instead.
     } else if request.uri().path() == "/sql" && request.method() == Method::POST {
-        sql_over_http::handle(request, sni_hostname, conn_pool, session_id).await
+        sql_over_http::handle(
+            request,
+            sni_hostname,
+            conn_pool,
+            session_id,
+            &config.http_config,
+        )
+        .await
     } else if request.uri().path() == "/sql" && request.method() == Method::OPTIONS {
         Response::builder()
             .header("Allow", "OPTIONS, POST")
@@ -275,23 +285,25 @@ pub async fn task_main(
             let conn_pool = conn_pool.clone();
 
             async move {
-                Ok::<_, Infallible>(hyper::service::service_fn(move |req: Request<Body>| {
-                    let sni_name = sni_name.clone();
-                    let conn_pool = conn_pool.clone();
+                Ok::<_, Infallible>(MetricService::new(hyper::service::service_fn(
+                    move |req: Request<Body>| {
+                        let sni_name = sni_name.clone();
+                        let conn_pool = conn_pool.clone();
 
-                    async move {
-                        let cancel_map = Arc::new(CancelMap::default());
-                        let session_id = uuid::Uuid::new_v4();
+                        async move {
+                            let cancel_map = Arc::new(CancelMap::default());
+                            let session_id = uuid::Uuid::new_v4();
 
-                        ws_handler(req, config, conn_pool, cancel_map, session_id, sni_name)
-                            .instrument(info_span!(
-                                "ws-client",
-                                session = %session_id,
-                                %peer_addr,
-                            ))
-                            .await
-                    }
-                }))
+                            ws_handler(req, config, conn_pool, cancel_map, session_id, sni_name)
+                                .instrument(info_span!(
+                                    "ws-client",
+                                    session = %session_id,
+                                    %peer_addr,
+                                ))
+                                .await
+                        }
+                    },
+                )))
             }
         },
     );
@@ -303,3 +315,41 @@ pub async fn task_main(
 
     Ok(())
 }
+
+struct MetricService<S> {
+    inner: S,
+}
+
+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();
+    }
+}
+
+impl<S, ReqBody> hyper::service::Service<Request<ReqBody>> for MetricService<S>
+where
+    S: hyper::service::Service<Request<ReqBody>>,
+{
+    type Response = S::Response;
+    type Error = S::Error;
+    type Future = S::Future;
+
+    fn poll_ready(&mut self, cx: &mut std::task::Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.inner.poll_ready(cx)
+    }
+
+    fn call(&mut self, req: Request<ReqBody>) -> Self::Future {
+        self.inner.call(req)
+    }
+}

proxy/src/proxy.rs

@@ -7,6 +7,7 @@ use crate::{
     compute::{self, PostgresConnection},
     config::{ProxyConfig, TlsConfig},
     console::{self, errors::WakeComputeError, messages::MetricsAuxInfo, Api},
+    http::StatusCode,
     metrics::{Ids, USAGE_METRICS},
     protocol2::WithClientIp,
     stream::{PqStream, Stream},
@@ -38,19 +39,55 @@ 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";
 
-static NUM_CONNECTIONS_ACCEPTED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
+pub static NUM_DB_CONNECTIONS_OPENED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(
-        "proxy_accepted_connections_total",
-        "Number of TCP client connections accepted.",
+        "proxy_opened_db_connections_total",
+        "Number of opened connections to a database.",
         &["protocol"],
     )
     .unwrap()
 });
 
-static NUM_CONNECTIONS_CLOSED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
+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"],
+    )
+    .unwrap()
+});
+
+pub static NUM_CLIENT_CONNECTION_OPENED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
+    register_int_counter_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"],
+    )
+    .unwrap()
+});
+
+pub static NUM_CONNECTIONS_ACCEPTED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
+    register_int_counter_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 TCP client connections closed.",
+        "Number of client connections closed.",
         &["protocol"],
     )
     .unwrap()
@@ -75,6 +112,15 @@ static NUM_CONNECTION_FAILURES: Lazy<IntCounterVec> = Lazy::new(|| {
     .unwrap()
 });
 
+static NUM_WAKEUP_FAILURES: Lazy<IntCounterVec> = Lazy::new(|| {
+    register_int_counter_vec!(
+        "proxy_connection_failures_breakdown",
+        "Number of wake-up failures (per kind).",
+        &["retry", "kind"],
+    )
+    .unwrap()
+});
+
 static NUM_BYTES_PROXIED_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(
         "proxy_io_bytes_per_client",
@@ -208,12 +254,16 @@ pub async fn handle_client<S: AsyncRead + AsyncWrite + Unpin>(
         "handling interactive connection from client"
     );
 
-    // The `closed` counter will increase when this future is destroyed.
+    let proto = mode.protocol_label();
+    NUM_CLIENT_CONNECTION_OPENED_COUNTER
+        .with_label_values(&[proto])
+        .inc();
     NUM_CONNECTIONS_ACCEPTED_COUNTER
-        .with_label_values(&[mode.protocol_label()])
+        .with_label_values(&[proto])
         .inc();
     scopeguard::defer! {
-        NUM_CONNECTIONS_CLOSED_COUNTER.with_label_values(&[mode.protocol_label()]).inc();
+        NUM_CLIENT_CONNECTION_CLOSED_COUNTER.with_label_values(&[proto]).inc();
+        NUM_CONNECTIONS_CLOSED_COUNTER.with_label_values(&[proto]).inc();
     }
 
     let tls = config.tls_config.as_ref();
@@ -248,7 +298,7 @@ pub async fn handle_client<S: AsyncRead + AsyncWrite + Unpin>(
         mode.allow_self_signed_compute(config),
     );
     cancel_map
-        .with_session(|session| client.connect_to_db(session, mode.allow_cleartext()))
+        .with_session(|session| client.connect_to_db(session, mode))
         .await
 }
 
@@ -397,6 +447,46 @@ impl ConnectMechanism for TcpMechanism<'_> {
     }
 }
 
+const fn bool_to_str(x: bool) -> &'static str {
+    if x {
+        "true"
+    } else {
+        "false"
+    }
+}
+
+fn report_error(e: &WakeComputeError, retry: bool) {
+    use crate::console::errors::ApiError;
+    let retry = bool_to_str(retry);
+    let kind = match e {
+        WakeComputeError::BadComputeAddress(_) => "bad_compute_address",
+        WakeComputeError::ApiError(ApiError::Transport(_)) => "api_transport_error",
+        WakeComputeError::ApiError(ApiError::Console {
+            status: StatusCode::LOCKED,
+            ref text,
+        }) if text.contains("written data quota exceeded")
+            || text.contains("the limit for current plan reached") =>
+        {
+            "quota_exceeded"
+        }
+        WakeComputeError::ApiError(ApiError::Console {
+            status: StatusCode::LOCKED,
+            ..
+        }) => "api_console_locked",
+        WakeComputeError::ApiError(ApiError::Console {
+            status: StatusCode::BAD_REQUEST,
+            ..
+        }) => "api_console_bad_request",
+        WakeComputeError::ApiError(ApiError::Console { status, .. })
+            if status.is_server_error() =>
+        {
+            "api_console_other_server_error"
+        }
+        WakeComputeError::ApiError(ApiError::Console { .. }) => "api_console_other_error",
+    };
+    NUM_WAKEUP_FAILURES.with_label_values(&[retry, kind]).inc();
+}
+
 /// Try to connect to the compute node, retrying if necessary.
 /// This function might update `node_info`, so we take it by `&mut`.
 #[tracing::instrument(skip_all)]
@@ -440,10 +530,12 @@ where
         match handle_try_wake(wake_res, num_retries) {
             Err(e) => {
                 error!(error = ?e, num_retries, retriable = false, "couldn't wake compute node");
+                report_error(&e, false);
                 return Err(e.into());
             }
             // failed to wake up but we can continue to retry
             Ok(ControlFlow::Continue(e)) => {
+                report_error(&e, true);
                 warn!(error = ?e, num_retries, retriable = true, "couldn't wake compute node");
             }
             // successfully woke up a compute node and can break the wakeup loop
@@ -682,7 +774,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin> Client<'_, S> {
     async fn connect_to_db(
         self,
         session: cancellation::Session<'_>,
-        allow_cleartext: bool,
+        mode: ClientMode,
     ) -> anyhow::Result<()> {
         let Self {
             mut stream,
@@ -698,7 +790,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin> Client<'_, S> {
         };
 
         let auth_result = match creds
-            .authenticate(&extra, &mut stream, allow_cleartext)
+            .authenticate(&extra, &mut stream, mode.allow_cleartext())
             .await
         {
             Ok(auth_result) => auth_result,
@@ -724,6 +816,14 @@ impl<S: AsyncRead + AsyncWrite + Unpin> Client<'_, S> {
             .or_else(|e| stream.throw_error(e))
             .await?;
 
+        let proto = mode.protocol_label();
+        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, reported_auth_ok, 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

safekeeper/src/http/routes.rs

@@ -374,8 +374,12 @@ pub fn make_router(conf: SafeKeeperConf) -> RouterBuilder<hyper::Body, ApiError>
     if conf.http_auth.is_some() {
         router = router.middleware(auth_middleware(|request| {
             #[allow(clippy::mutable_key_type)]
-            static ALLOWLIST_ROUTES: Lazy<HashSet<Uri>> =
-                Lazy::new(|| ["/v1/status"].iter().map(|v| v.parse().unwrap()).collect());
+            static ALLOWLIST_ROUTES: Lazy<HashSet<Uri>> = Lazy::new(|| {
+                ["/v1/status", "/metrics"]
+                    .iter()
+                    .map(|v| v.parse().unwrap())
+                    .collect()
+            });
             if ALLOWLIST_ROUTES.contains(request.uri()) {
                 None
             } else {

test_runner/performance/test_wal_backpressure.py

@@ -65,7 +65,7 @@ def start_heavy_write_workload(env: PgCompare, n_tables: int, scale: int, num_it
 
     def start_single_table_workload(table_id: int):
         for _ in range(num_iters):
-            with env.pg.connect().cursor() as cur:
+            with env.pg.connect(options="-cstatement_timeout=300s").cursor() as cur:
                 cur.execute(
                     f"INSERT INTO t{table_id} SELECT FROM generate_series(1,{new_rows_each_update})"
                 )

test_runner/regress/test_wal_acceptor_async.py

@@ -6,6 +6,7 @@ from pathlib import Path
 from typing import List, Optional
 
 import asyncpg
+import pytest
 import toml
 from fixtures.log_helper import getLogger
 from fixtures.neon_fixtures import Endpoint, NeonEnv, NeonEnvBuilder, Safekeeper
@@ -597,7 +598,10 @@ async def run_wal_lagging(env: NeonEnv, endpoint: Endpoint, test_output_dir: Pat
     assert res == expected_sum
 
 
-# do inserts while restarting postgres and messing with safekeeper addresses
+# Do inserts while restarting postgres and messing with safekeeper addresses.
+# The test takes more than default 5 minutes on Postgres 16,
+# see https://github.com/neondatabase/neon/issues/5305
+@pytest.mark.timeout(600)
 def test_wal_lagging(neon_env_builder: NeonEnvBuilder, test_output_dir: Path):
     neon_env_builder.num_safekeepers = 3
     env = neon_env_builder.init_start()