Silence test failure caused by expected error in log.

If the uploads after compaction happen slowly, they might have
finished before the pageserver is shut down. The L0 files have been
uploaded, so no data is lost, but then the query later in the test
will need to download all the L0 files, and causes the test to fail
because it specifically checks that download happens on-demand, not
all at once.

pageserver/src/basebackup.rs

@@ -10,7 +10,7 @@
 //! This module is responsible for creation of such tarball
 //! from data stored in object storage.
 //!
-use anyhow::{anyhow, bail, ensure, Context};
+use anyhow::{anyhow, ensure, Context, Result};
 use bytes::{BufMut, BytesMut};
 use fail::fail_point;
 use std::fmt::Write as FmtWrite;
@@ -27,7 +27,8 @@ use tracing::*;
 ///
 use tokio_tar::{Builder, EntryType, Header};
 
-use crate::tenant::Timeline;
+use crate::tenant::TimelineRequestContext;
+use crate::tenant::{PageReconstructError, Timeline};
 use pageserver_api::reltag::{RelTag, SlruKind};
 
 use postgres_ffi::pg_constants::{DEFAULTTABLESPACE_OID, GLOBALTABLESPACE_OID};
@@ -52,7 +53,8 @@ pub async fn send_basebackup_tarball<'a, W>(
     req_lsn: Option<Lsn>,
     prev_lsn: Option<Lsn>,
     full_backup: bool,
-) -> anyhow::Result<()>
+    ctx: &'a TimelineRequestContext,
+) -> Result<(), PageReconstructError>
 where
     W: AsyncWrite + Send + Sync + Unpin,
 {
@@ -91,8 +93,10 @@ where
 
     // Consolidate the derived and the provided prev_lsn values
     let prev_lsn = if let Some(provided_prev_lsn) = prev_lsn {
-        if backup_prev != Lsn(0) {
-            ensure!(backup_prev == provided_prev_lsn);
+        if backup_prev != Lsn(0) && backup_prev != provided_prev_lsn {
+            return Err(PageReconstructError::Other(anyhow!(
+                "prev LSN doesn't match"
+            )));
         }
         provided_prev_lsn
     } else {
@@ -110,6 +114,7 @@ where
         lsn: backup_lsn,
         prev_record_lsn: prev_lsn,
         full_backup,
+        ctx,
     };
     basebackup
         .send_tarball()
@@ -129,13 +134,14 @@ where
     lsn: Lsn,
     prev_record_lsn: Lsn,
     full_backup: bool,
+    ctx: &'a TimelineRequestContext,
 }
 
 impl<'a, W> Basebackup<'a, W>
 where
     W: AsyncWrite + Send + Sync + Unpin,
 {
-    async fn send_tarball(mut self) -> anyhow::Result<()> {
+    async fn send_tarball(mut self) -> Result<(), PageReconstructError> {
         // TODO include checksum
 
         // Create pgdata subdirs structure
@@ -171,45 +177,67 @@ where
             SlruKind::MultiXactOffsets,
             SlruKind::MultiXactMembers,
         ] {
-            for segno in self.timeline.list_slru_segments(kind, self.lsn).await? {
+            for segno in self
+                .timeline
+                .list_slru_segments(kind, self.lsn, self.ctx)
+                .await?
+            {
                 self.add_slru_segment(kind, segno).await?;
             }
         }
 
         // Create tablespace directories
-        for ((spcnode, dbnode), has_relmap_file) in self.timeline.list_dbdirs(self.lsn).await? {
+        for ((spcnode, dbnode), has_relmap_file) in
+            self.timeline.list_dbdirs(self.lsn, self.ctx).await?
+        {
             self.add_dbdir(spcnode, dbnode, has_relmap_file).await?;
 
             // Gather and send relational files in each database if full backup is requested.
             if self.full_backup {
-                for rel in self.timeline.list_rels(spcnode, dbnode, self.lsn).await? {
+                for rel in self
+                    .timeline
+                    .list_rels(spcnode, dbnode, self.lsn, self.ctx)
+                    .await?
+                {
                     self.add_rel(rel).await?;
                 }
             }
         }
-        for xid in self.timeline.list_twophase_files(self.lsn).await? {
+        for xid in self
+            .timeline
+            .list_twophase_files(self.lsn, self.ctx)
+            .await?
+        {
             self.add_twophase_file(xid).await?;
         }
 
         fail_point!("basebackup-before-control-file", |_| {
-            bail!("failpoint basebackup-before-control-file")
+            Err(PageReconstructError::from(anyhow!(
+                "failpoint basebackup-before-control-file"
+            )))
         });
 
         // Generate pg_control and bootstrap WAL segment.
         self.add_pgcontrol_file().await?;
-        self.ar.finish().await?;
+        self.ar.finish().await.context("could not finish tarball")?;
         debug!("all tarred up!");
         Ok(())
     }
 
-    async fn add_rel(&mut self, tag: RelTag) -> anyhow::Result<()> {
-        let nblocks = self.timeline.get_rel_size(tag, self.lsn, false).await?;
+    async fn add_rel(&mut self, tag: RelTag) -> Result<(), PageReconstructError> {
+        let nblocks = self
+            .timeline
+            .get_rel_size(tag, self.lsn, false, self.ctx)
+            .await?;
 
         // If the relation is empty, create an empty file
         if nblocks == 0 {
             let file_name = tag.to_segfile_name(0);
             let header = new_tar_header(&file_name, 0)?;
-            self.ar.append(&header, &mut io::empty()).await?;
+            self.ar
+                .append(&header, &mut io::empty())
+                .await
+                .context("could not write empty relfile to tar stream")?;
             return Ok(());
         }
 
@@ -218,19 +246,21 @@ where
         let mut seg = 0;
         while startblk < nblocks {
             let endblk = std::cmp::min(startblk + RELSEG_SIZE, nblocks);
-
             let mut segment_data: Vec<u8> = vec![];
             for blknum in startblk..endblk {
                 let img = self
                     .timeline
-                    .get_rel_page_at_lsn(tag, blknum, self.lsn, false)
+                    .get_rel_page_at_lsn(tag, blknum, self.lsn, false, self.ctx)
                     .await?;
                 segment_data.extend_from_slice(&img[..]);
             }
 
             let file_name = tag.to_segfile_name(seg as u32);
             let header = new_tar_header(&file_name, segment_data.len() as u64)?;
-            self.ar.append(&header, segment_data.as_slice()).await?;
+            self.ar
+                .append(&header, segment_data.as_slice())
+                .await
+                .context("could not write relfile segment to tar stream")?;
 
             seg += 1;
             startblk = endblk;
@@ -245,14 +275,14 @@ where
     async fn add_slru_segment(&mut self, slru: SlruKind, segno: u32) -> anyhow::Result<()> {
         let nblocks = self
             .timeline
-            .get_slru_segment_size(slru, segno, self.lsn)
+            .get_slru_segment_size(slru, segno, self.lsn, self.ctx)
             .await?;
 
         let mut slru_buf: Vec<u8> = Vec::with_capacity(nblocks as usize * BLCKSZ as usize);
         for blknum in 0..nblocks {
             let img = self
                 .timeline
-                .get_slru_page_at_lsn(slru, segno, blknum, self.lsn)
+                .get_slru_page_at_lsn(slru, segno, blknum, self.lsn, self.ctx)
                 .await?;
 
             if slru == SlruKind::Clog {
@@ -287,7 +317,7 @@ where
         let relmap_img = if has_relmap_file {
             let img = self
                 .timeline
-                .get_relmap_file(spcnode, dbnode, self.lsn)
+                .get_relmap_file(spcnode, dbnode, self.lsn, self.ctx)
                 .await?;
             ensure!(img.len() == 512);
             Some(img)
@@ -323,7 +353,7 @@ where
             if !has_relmap_file
                 && self
                     .timeline
-                    .list_rels(spcnode, dbnode, self.lsn)
+                    .list_rels(spcnode, dbnode, self.lsn, self.ctx)
                     .await?
                     .is_empty()
             {
@@ -356,7 +386,10 @@ where
     // Extract twophase state files
     //
     async fn add_twophase_file(&mut self, xid: TransactionId) -> anyhow::Result<()> {
-        let img = self.timeline.get_twophase_file(xid, self.lsn).await?;
+        let img = self
+            .timeline
+            .get_twophase_file(xid, self.lsn, self.ctx)
+            .await?;
 
         let mut buf = BytesMut::new();
         buf.extend_from_slice(&img[..]);
@@ -394,12 +427,12 @@ where
 
         let checkpoint_bytes = self
             .timeline
-            .get_checkpoint(self.lsn)
+            .get_checkpoint(self.lsn, self.ctx)
             .await
             .context("failed to get checkpoint bytes")?;
         let pg_control_bytes = self
             .timeline
-            .get_control_file(self.lsn)
+            .get_control_file(self.lsn, self.ctx)
             .await
             .context("failed get control bytes")?;
 

pageserver/src/bin/pageserver.rs

@@ -13,8 +13,8 @@ use tracing::*;
 use metrics::set_build_info_metric;
 use pageserver::{
     config::{defaults::*, PageServerConf},
+    context::{DownloadBehavior, RequestContext, TaskKind},
     http, page_cache, page_service, task_mgr,
-    task_mgr::TaskKind,
     task_mgr::{
         BACKGROUND_RUNTIME, COMPUTE_REQUEST_RUNTIME, MGMT_REQUEST_RUNTIME, WALRECEIVER_RUNTIME,
     },
@@ -303,62 +303,79 @@ fn start_pageserver(conf: &'static PageServerConf) -> anyhow::Result<()> {
     {
         let _rt_guard = MGMT_REQUEST_RUNTIME.enter();
 
+        let mgmt_ctx = RequestContext::new(TaskKind::HttpEndpointListener, DownloadBehavior::Error);
+        let cancellation_token = Box::leak(Box::new(mgmt_ctx.cancellation_token().clone()));
         let router = http::make_router(conf, auth.clone(), remote_storage)?
             .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(task_mgr::shutdown_watcher());
+            .with_graceful_shutdown(cancellation_token.cancelled());
 
         task_mgr::spawn(
             MGMT_REQUEST_RUNTIME.handle(),
-            TaskKind::HttpEndpointListener,
-            None,
-            None,
             "http endpoint listener",
             true,
             async {
-                server.await?;
-                Ok(())
+                match server.await {
+                    Ok(()) => info!("HTTP endpoint listener shut down"),
+                    Err(err) => error!("HTTP endpoint listener shut down with error: {err:?}"),
+                }
             },
         );
+    }
 
-        if let Some(metric_collection_endpoint) = &conf.metric_collection_endpoint {
-            task_mgr::spawn(
-                MGMT_REQUEST_RUNTIME.handle(),
-                TaskKind::MetricsCollection,
-                None,
-                None,
-                "consumption metrics collection",
-                true,
-                async move {
-                    pageserver::consumption_metrics::collect_metrics(
-                        metric_collection_endpoint,
-                        conf.metric_collection_interval,
-                        conf.id,
-                    )
-                    .instrument(info_span!("metrics_collection"))
-                    .await?;
-                    Ok(())
-                },
-            );
-        }
+    if let Some(metric_collection_endpoint) = &conf.metric_collection_endpoint {
+        let metrics_ctx = RequestContext::new(
+            TaskKind::MetricsCollection,
+            DownloadBehavior::Error, // metrics collector shouldn't be downloading anything
+        );
+        task_mgr::spawn(
+            MGMT_REQUEST_RUNTIME.handle(),
+            "consumption metrics collection",
+            true,
+            pageserver::consumption_metrics::collect_metrics(
+                metric_collection_endpoint,
+                conf.metric_collection_interval,
+                conf.id,
+                metrics_ctx,
+            )
+            .instrument(info_span!("metrics_collection")),
+        );
     }
 
     // Spawn a task to listen for libpq connections. It will spawn further tasks
     // for each connection. We created the listener earlier already.
-    task_mgr::spawn(
-        COMPUTE_REQUEST_RUNTIME.handle(),
-        TaskKind::LibpqEndpointListener,
-        None,
-        None,
-        "libpq endpoint listener",
-        true,
-        async move {
-            page_service::libpq_listener_main(conf, auth, pageserver_listener, conf.auth_type).await
-        },
-    );
+    {
+        let libpq_ctx = RequestContext::new(
+            TaskKind::LibpqEndpointListener,
+            // listener task shouldn't need to download anything. (We will
+            // create a separate sub-contexts for each connection, with their
+            // own download behavior. This context is used only to listen and
+            // accept connections.)
+            DownloadBehavior::Error,
+        );
+        task_mgr::spawn(
+            COMPUTE_REQUEST_RUNTIME.handle(),
+            "libpq endpoint listener",
+            true,
+            async move {
+                match page_service::libpq_listener_main(
+                    conf,
+                    auth,
+                    pageserver_listener,
+                    conf.auth_type,
+                    libpq_ctx,
+                )
+                .await
+                {
+                    Ok(()) => info!("libpq endpoint listener shut down"),
+                    Err(err) => error!("libpq endpoint listener shut down with error: {err:?}"),
+                }
+            },
+        );
+    }
 
     // All started up! Now just sit and wait for shutdown signal.
     signals.handle(|signal| match signal {
@@ -375,7 +392,7 @@ fn start_pageserver(conf: &'static PageServerConf) -> anyhow::Result<()> {
                 "Got {}. Terminating gracefully in fast shutdown mode",
                 signal.name()
             );
-            BACKGROUND_RUNTIME.block_on(pageserver::shutdown_pageserver(0));
+            BACKGROUND_RUNTIME.block_on(task_mgr::shutdown_pageserver(0));
             unreachable!()
         }
     })

pageserver/src/consumption_metrics.rs

@@ -9,9 +9,8 @@ use tracing::*;
 use utils::id::NodeId;
 use utils::id::TimelineId;
 
-use crate::task_mgr;
+use crate::context::RequestContext;
 use crate::tenant::mgr;
-use pageserver_api::models::TenantState;
 use utils::id::TenantId;
 
 use serde::{Deserialize, Serialize};
@@ -138,12 +137,13 @@ struct EventChunk<'a> {
     events: &'a [ConsumptionMetric],
 }
 
-/// Main thread that serves metrics collection
+/// Main task that serves metrics collection
 pub async fn collect_metrics(
     metric_collection_endpoint: &Url,
     metric_collection_interval: Duration,
     node_id: NodeId,
-) -> anyhow::Result<()> {
+    metrics_ctx: RequestContext,
+) {
     let mut ticker = tokio::time::interval(metric_collection_interval);
 
     info!("starting collect_metrics");
@@ -154,12 +154,15 @@ pub async fn collect_metrics(
 
     loop {
         tokio::select! {
-            _ = task_mgr::shutdown_watcher() => {
+            _ = metrics_ctx.cancelled() => {
                 info!("collect_metrics received cancellation request");
-                return Ok(());
+                return;
             },
             _ = ticker.tick() => {
-                collect_metrics_task(&client, &mut cached_metrics, metric_collection_endpoint, node_id).await?;
+                if let Err(err) = collect_metrics_task(&client, &mut cached_metrics, metric_collection_endpoint, node_id, &metrics_ctx).await {
+                    // Log the error and continue
+                    error!("metrics collection failed: {err:?}");
+                }
             }
         }
     }
@@ -174,6 +177,7 @@ pub async fn collect_metrics_task(
     cached_metrics: &mut HashMap<ConsumptionMetricsKey, u64>,
     metric_collection_endpoint: &reqwest::Url,
     node_id: NodeId,
+    ctx: &RequestContext,
 ) -> anyhow::Result<()> {
     let mut current_metrics: Vec<(ConsumptionMetricsKey, u64)> = Vec::new();
     trace!(
@@ -186,18 +190,27 @@ pub async fn collect_metrics_task(
 
     // iterate through list of Active tenants and collect metrics
     for (tenant_id, tenant_state) in tenants {
-        if tenant_state != TenantState::Active {
+        if ctx.is_cancelled() {
             continue;
         }
-
-        let tenant = mgr::get_tenant(tenant_id, true).await?;
+        let tenant = mgr::get_tenant(tenant_id).await?;
+        // If the tenant was shut down while while we were looking elsewhere, skip it.
+        let tenant_ctx = match tenant.get_context(ctx) {
+            Ok(ctx) => ctx,
+            Err(_state) => {
+                debug!(
+                    "skipping metrics collection for tenant {tenant_id} because it is not active"
+                );
+                continue;
+            }
+        };
 
         let mut tenant_resident_size = 0;
 
         // iterate through list of timelines in tenant
         for timeline in tenant.list_timelines().iter() {
             // collect per-timeline metrics only for active timelines
-            if timeline.is_active() {
+            if let Ok(timeline_ctx) = timeline.get_context(&tenant_ctx) {
                 let timeline_written_size = u64::from(timeline.get_last_record_lsn());
 
                 current_metrics.push((
@@ -209,7 +222,8 @@ pub async fn collect_metrics_task(
                     timeline_written_size,
                 ));
 
-                let (timeline_logical_size, is_exact) = timeline.get_current_logical_size()?;
+                let (timeline_logical_size, is_exact) =
+                    timeline.get_current_logical_size(&timeline_ctx)?;
                 // Only send timeline logical size when it is fully calculated.
                 if is_exact {
                     current_metrics.push((

pageserver/src/context.rs

@@ -0,0 +1,348 @@
+//!
+//! Most async functions throughout the pageserver take a `ctx: &RequestContext`
+//! argument. It is used to control desired behaviour of the operation, and to
+//! allow cancelling the operation gracefully.
+//!
+//! # Context hierarchy
+//!
+//! RequestContext's form a hierarchy. For example:
+//!
+//!  listener context (LibpqEndpointListener)
+//!    connection context (PageRequestHandler)
+//!      per-request context (PageRequestHandler)
+//!
+//! The top "listener context" is created at pageserver startup. The tokio
+//! task that listens on the libpq protocol TCP port holds that context. When
+//! it accepts a connection, it spawns a new task to handle that connection
+//! and creates a new per-connection context for it. The mgmt API listener,
+//! background jobs, and other things form separate but similar hierarchies.
+//!
+//! Usually, each tokio task has its own context, but it's not a strict
+//! requirement and some tasks can hold multiple contexts, and converesely,
+//! some contexts are shared by multiple tasks that work together to perform
+//! some operation.
+//!
+//! The hierarchy is not explictly tracked in the RequestContext struct
+//! itself, but only by their cancellation tokens. It's entirely possible for
+//! the parent context to be dropped before its children.
+//!
+//! # Tenant and Timeline registration
+//!
+//! Most operations are performed on a particular Tenant or Timeline. When
+//! operating on a Tenant or Timeline, it's important that the Tenant/Timeline
+//! isn't detached or deleted while there are tasks working on it. To ensure
+//! that, a RequestContext can be registered with a Tenant or Timeline. See
+//! `Tenant::register_context` and `Timeline::register_context` When
+//! shutting down a Tenant or Timeline, the shutdown routine cancels all the
+//! registered contexts, and waits for them to be dropped before completing
+//! the shutdown.
+//!
+//! To enforce that you hold a registered context when operating on a Tenant
+//! or Timeline, most functions take a TimelineRequestContext or
+//! TenantRequestContext reference as argument.
+//!
+//! NOTE: The Tenant / Timeline registration is separate from the context
+//! hierarchy. You can create a new RequestContext with TimelineRequestContext
+//! as the parent, and register it with a different timeline, for example.
+//!
+//! # Notes
+//!
+//! All RequestContexts in the system have a unique ID, and are also tracked
+//! in a global hash table, CONTEXTS.
+//!
+//! - Futures are normally not assumed to be async cancellation-safe. Pass a
+//!   RequestContext as argument and use cancel() on it instead.
+//!
+//! - If you perform an operation that depends on some external actor or the
+//!   network, use the cancellation token to check for cancellation
+//!
+//! - By convention, the appropriate context for current operation is carried in
+//!   a variable called 'ctx'. If a function handles multiple contexts, it's
+//!   best to *not* have a variable called 'ctx', to force you to think which
+//!   one to use in each call.
+//!
+//! # TODO
+//! - include a unique request ID for tracing
+//!
+
+use once_cell::sync::Lazy;
+use tokio_util::sync::CancellationToken;
+use tracing::{info, warn};
+
+use std::collections::HashMap;
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::Mutex;
+
+/// Each RequestContext has a unique context ID. It's just an increasing
+/// number that we assign.
+static NEXT_CONTEXT_ID: AtomicU64 = AtomicU64::new(1);
+
+/// Global registry of contexts
+static CONTEXTS: Lazy<Mutex<HashMap<RequestContextId, (TaskKind, CancellationToken)>>> =
+    Lazy::new(|| Mutex::new(HashMap::new()));
+
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub struct RequestContextId(u64);
+
+///
+pub struct RequestContext {
+    context_id: RequestContextId,
+    task_kind: TaskKind,
+
+    download_behavior: DownloadBehavior,
+    cancellation_token: CancellationToken,
+}
+
+/// DownloadBehavior option specifies the behavior if completing the operation
+/// would require downloading a layer file from remote storage.
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub enum DownloadBehavior {
+    /// Download the layer file. It can take a while.
+    Download,
+
+    /// Download the layer file, but print a warning to the log. This should be used
+    /// in code where the layer file is expected to already exist locally.
+    Warn,
+
+    /// Return a PageReconstructError::NeedsDownload error
+    Error,
+}
+
+///
+/// There are many kinds of tasks in the system. Some are associated with a particular
+/// tenant or timeline, while others are global.
+///
+/// The task kind affects the shutdown sequence on pageserver shutdown and on detach
+/// of an individual tenant. For example, when shutting down the pageserver, we shut
+/// down the LibpqEndpointListeners first, so that we don't accept any more client
+/// connections while we perform the rest of the shutdown duties. See
+/// [`Timeline::graceful_shutdown and`] and [`tenant_mgr::shutdown_pageserver`]
+/// for details.
+///
+/// Note that we don't try to limit how many task of a certain kind can be running
+/// at the same time.
+///
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum TaskKind {
+    // libpq listener task. It just accepts connection and spawns a
+    // PageRequestHandler task for each connection.
+    LibpqEndpointListener,
+
+    // HTTP endpoint listener.
+    HttpEndpointListener,
+
+    // Task that handles a single connection. A PageRequestHandler task
+    // starts detached from any particular tenant or timeline, but it can be
+    // associated with one later, after receiving a command from the client.
+    PageRequestHandler,
+
+    // Context for one management API request
+    MgmtRequest,
+
+    // Manages the WAL receiver connection for one timeline. It subscribes to
+    // events from storage_broker, decides which safekeeper to connect to. It spawns a
+    // separate WalReceiverConnection task to handle each connection.
+    WalReceiverManager,
+
+    // Handles a connection to a safekeeper, to stream WAL to a timeline.
+    WalReceiverConnection,
+
+    // Garbage collection worker. One per tenant
+    GarbageCollector,
+
+    // Compaction. One per tenant.
+    Compaction,
+
+    // Initial logical size calculation
+    InitialLogicalSizeCalculation,
+
+    // Task that flushes frozen in-memory layers to disk
+    LayerFlush,
+
+    // Task that uploads a file to remote storage
+    RemoteUploadTask,
+
+    // Task that downloads a file from remote storage
+    RemoteDownloadTask,
+
+    // task that handles the initial downloading of all tenants
+    InitialLoad,
+
+    // task that handles attaching a tenant
+    Attach,
+
+    // task that handles metrics collection
+    MetricsCollection,
+
+    // task that drives downloading layers
+    DownloadAllRemoteLayers,
+
+    // Only used in unit tests
+    UnitTest,
+}
+
+impl Drop for RequestContext {
+    fn drop(&mut self) {
+        CONTEXTS
+            .lock()
+            .unwrap()
+            .remove(&self.context_id)
+            .expect("context is not in global registry");
+    }
+}
+
+impl RequestContext {
+    /// Create a new RequestContext
+    pub fn new(task_kind: TaskKind, download_behavior: DownloadBehavior) -> Self {
+        let cancellation_token = CancellationToken::new();
+        let context_id = RequestContextId(NEXT_CONTEXT_ID.fetch_add(1, Ordering::Relaxed));
+        CONTEXTS
+            .lock()
+            .unwrap()
+            .insert(context_id, (task_kind, cancellation_token.clone()));
+
+        RequestContext {
+            task_kind,
+            context_id,
+            download_behavior,
+            cancellation_token,
+        }
+    }
+
+    /// Create a new RequestContext, as a child of 'parent'.
+    pub fn with_parent(
+        task_kind: TaskKind,
+        download_behavior: DownloadBehavior,
+        parent: &RequestContext,
+    ) -> Self {
+        let cancellation_token = parent.cancellation_token.child_token();
+        let context_id = RequestContextId(NEXT_CONTEXT_ID.fetch_add(1, Ordering::Relaxed));
+        CONTEXTS
+            .lock()
+            .unwrap()
+            .insert(context_id, (task_kind, cancellation_token.clone()));
+
+        RequestContext {
+            task_kind,
+            context_id,
+            download_behavior,
+            cancellation_token,
+        }
+    }
+
+    pub fn context_id(&self) -> RequestContextId {
+        self.context_id
+    }
+
+    pub fn task_kind(&self) -> TaskKind {
+        self.task_kind
+    }
+
+    pub fn download_behavior(&self) -> DownloadBehavior {
+        self.download_behavior
+    }
+
+    pub fn cancellation_token(&self) -> &CancellationToken {
+        &self.cancellation_token
+    }
+
+    pub fn is_cancelled(&self) -> bool {
+        self.cancellation_token.is_cancelled()
+    }
+
+    pub async fn cancelled(&self) {
+        self.cancellation_token.cancelled().await
+    }
+}
+
+///
+/// Cancel all the contexts in 'context_ids' and wait for them to finish.
+///
+/// Whenever we notice that one of the contexts has finished, it is removed
+/// from 'context_ids'. On return, it is empty.
+///
+pub async fn cancel_and_wait(context_ids: &mut Vec<RequestContextId>) {
+    {
+        let contexts = CONTEXTS.lock().unwrap();
+        context_ids.retain(|context_id| {
+            if let Some((task_kind, cancellation_token)) = contexts.get(context_id) {
+                info!("cancelling task {task_kind:?} with ID {context_id:?}");
+                cancellation_token.cancel();
+                true
+            } else {
+                // Already gone
+                false
+            }
+        });
+    }
+    wait_contexts_to_finish(context_ids).await
+}
+
+async fn wait_contexts_to_finish(context_ids: &mut Vec<RequestContextId>) {
+    let mut n = 0;
+    while !context_ids.is_empty() {
+        {
+            let contexts = CONTEXTS.lock().unwrap();
+            while let Some(context_id) = context_ids.last() {
+                if let Some((task_kind, _cancellation_token)) = contexts.get(context_id) {
+                    info!("waiting for task {task_kind:?} with ID {context_id:?} to finish");
+                    break;
+                } else {
+                    context_ids.pop();
+                }
+            }
+        }
+        if !context_ids.is_empty() {
+            crate::exponential_backoff(
+                n,
+                crate::DEFAULT_BASE_BACKOFF_SECONDS,
+                crate::DEFAULT_MAX_BACKOFF_SECONDS,
+            )
+            .await;
+            n += 1;
+        }
+    }
+}
+
+/// Cancel and wait for all tasks of given 'kind' to finish
+pub async fn shutdown_tasks(kind: TaskKind) {
+    let mut context_ids = Vec::new();
+    {
+        let contexts = CONTEXTS.lock().unwrap();
+        for (&context_id, (task_kind, cancellation_token)) in contexts.iter() {
+            if *task_kind == kind {
+                cancellation_token.cancel();
+                context_ids.push(context_id);
+            }
+        }
+    }
+    wait_contexts_to_finish(&mut context_ids).await
+}
+
+/// Cancel all remaining contexts.
+///
+/// This is used as part of pageserver shutdown. We have already shut down all
+/// tasks / contexts, this is just a backstop or sanity check to make sure we
+/// didn't miss anything. Hence, also print a warning for any remaining tasks.
+pub async fn shutdown_all_tasks() {
+    loop {
+        let mut context_ids = Vec::new();
+        {
+            let contexts = CONTEXTS.lock().unwrap();
+
+            if contexts.is_empty() {
+                return;
+            }
+
+            for (&context_id, (task_kind, cancellation_token)) in contexts.iter() {
+                cancellation_token.cancel();
+                context_ids.push(context_id);
+                warn!(
+                    "unexpected task of kind {:?} with ID {:?} still running",
+                    *task_kind, context_id
+                );
+            }
+        }
+        wait_contexts_to_finish(&mut context_ids).await
+    }
+}

pageserver/src/http/routes.rs

@@ -4,16 +4,16 @@ use anyhow::{anyhow, Context, Result};
 use hyper::StatusCode;
 use hyper::{Body, Request, Response, Uri};
 use remote_storage::GenericRemoteStorage;
-use tokio_util::sync::CancellationToken;
 use tracing::*;
 
 use super::models::{
     StatusResponse, TenantConfigRequest, TenantCreateRequest, TenantCreateResponse, TenantInfo,
     TimelineCreateRequest, TimelineInfo,
 };
+use crate::context::{DownloadBehavior, RequestContext, TaskKind};
 use crate::pgdatadir_mapping::LsnForTimestamp;
 use crate::tenant::config::TenantConfOpt;
-use crate::tenant::{PageReconstructError, Timeline};
+use crate::tenant::{PageReconstructError, Timeline, TimelineRequestContext};
 use crate::{config::PageServerConf, tenant::mgr};
 use utils::{
     auth::JwtAuth,
@@ -80,6 +80,16 @@ fn check_permission(request: &Request<Body>, tenant_id: Option<TenantId>) -> Res
 fn apierror_from_prerror(err: PageReconstructError) -> ApiError {
     match err {
         PageReconstructError::Other(err) => ApiError::InternalServerError(err),
+        PageReconstructError::NeedsDownload(_, _) => {
+            // This shouldn't happen, because we use a RequestContext that requests to
+            // download any missing layer files on-demand.
+            ApiError::InternalServerError(anyhow::anyhow!(
+                "would need to download remote layer file"
+            ))
+        }
+        PageReconstructError::Cancelled => {
+            ApiError::InternalServerError(anyhow::anyhow!("request was cancelled"))
+        }
         PageReconstructError::WalRedo(err) => {
             ApiError::InternalServerError(anyhow::Error::new(err))
         }
@@ -90,25 +100,27 @@ fn apierror_from_prerror(err: PageReconstructError) -> ApiError {
 async fn build_timeline_info(
     timeline: &Arc<Timeline>,
     include_non_incremental_logical_size: bool,
+    ctx: Option<&TimelineRequestContext>,
 ) -> anyhow::Result<TimelineInfo> {
-    let mut info = build_timeline_info_common(timeline)?;
+    let mut info = build_timeline_info_common(timeline, ctx)?;
     if include_non_incremental_logical_size {
-        // XXX we should be using spawn_ondemand_logical_size_calculation here.
-        // Otherwise, if someone deletes the timeline / detaches the tenant while
-        // we're executing this function, we will outlive the timeline on-disk state.
-        info.current_logical_size_non_incremental = Some(
-            timeline
-                .get_current_logical_size_non_incremental(
-                    info.last_record_lsn,
-                    CancellationToken::new(),
-                )
-                .await?,
-        );
+        if let Some(ctx) = ctx {
+            info.current_logical_size_non_incremental = Some(
+                timeline
+                    .get_current_logical_size_non_incremental(info.last_record_lsn, ctx)
+                    .await?,
+            );
+        } else {
+            info!("could not calculate non-incremental size for timeline because it is not active");
+        }
     }
     Ok(info)
 }
 
-fn build_timeline_info_common(timeline: &Arc<Timeline>) -> anyhow::Result<TimelineInfo> {
+fn build_timeline_info_common(
+    timeline: &Arc<Timeline>,
+    ctx: Option<&TimelineRequestContext>,
+) -> anyhow::Result<TimelineInfo> {
     let last_record_lsn = timeline.get_last_record_lsn();
     let (wal_source_connstr, last_received_msg_lsn, last_received_msg_ts) = {
         let guard = timeline.last_received_wal.lock().unwrap();
@@ -128,12 +140,16 @@ fn build_timeline_info_common(timeline: &Arc<Timeline>) -> anyhow::Result<Timeli
         Lsn(0) => None,
         lsn @ Lsn(_) => Some(lsn),
     };
-    let current_logical_size = match timeline.get_current_logical_size() {
-        Ok((size, _)) => Some(size),
-        Err(err) => {
-            error!("Timeline info creation failed to get current logical size: {err:?}");
-            None
+    let current_logical_size = if let Some(ctx) = ctx {
+        match timeline.get_current_logical_size(ctx) {
+            Ok((size, _)) => Some(size),
+            Err(err) => {
+                error!("Timeline info creation failed to get current logical size: {err:?}");
+                None
+            }
         }
+    } else {
+        None
     };
     let current_physical_size = Some(timeline.layer_size_sum().approximate_is_ok());
     let state = timeline.current_state();
@@ -179,20 +195,23 @@ async fn timeline_create_handler(mut request: Request<Body>) -> Result<Response<
         .new_timeline_id
         .unwrap_or_else(TimelineId::generate);
 
-    let tenant = mgr::get_tenant(tenant_id, true)
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, tenant_ctx) = mgr::get_active_tenant(tenant_id, &ctx)
         .await
         .map_err(ApiError::NotFound)?;
     match tenant.create_timeline(
         new_timeline_id,
         request_data.ancestor_timeline_id.map(TimelineId::from),
         request_data.ancestor_start_lsn,
-        request_data.pg_version.unwrap_or(crate::DEFAULT_PG_VERSION)
+        request_data.pg_version.unwrap_or(crate::DEFAULT_PG_VERSION),
+        &tenant_ctx,
     )
     .instrument(info_span!("timeline_create", tenant = %tenant_id, new_timeline = ?request_data.new_timeline_id, timeline_id = %new_timeline_id, lsn=?request_data.ancestor_start_lsn, pg_version=?request_data.pg_version))
     .await {
-        Ok(Some(new_timeline)) => {
+        Ok(Some((new_timeline, timeline_ctx))) => {
             // Created. Construct a TimelineInfo for it.
-            let timeline_info = build_timeline_info_common(&new_timeline)
+            let timeline_info = build_timeline_info_common(&new_timeline, Some(&timeline_ctx))
                 .map_err(ApiError::InternalServerError)?;
             json_response(StatusCode::CREATED, timeline_info)
         }
@@ -207,21 +226,25 @@ async fn timeline_list_handler(request: Request<Body>) -> Result<Response<Body>,
         query_param_present(&request, "include-non-incremental-logical-size");
     check_permission(&request, Some(tenant_id))?;
 
+    let top_ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
     let response_data = async {
-        let tenant = mgr::get_tenant(tenant_id, true)
+        let (tenant, tenant_ctx) = mgr::get_active_tenant(tenant_id, &top_ctx)
             .await
             .map_err(ApiError::NotFound)?;
         let timelines = tenant.list_timelines();
 
         let mut response_data = Vec::with_capacity(timelines.len());
         for timeline in timelines {
-            let timeline_info =
-                build_timeline_info(&timeline, include_non_incremental_logical_size)
-                    .await
-                    .context(
-                        "Failed to convert tenant timeline {timeline_id} into the local one: {e:?}",
-                    )
-                    .map_err(ApiError::InternalServerError)?;
+            let timeline_ctx = timeline.get_context(&tenant_ctx).ok();
+            let timeline_info = build_timeline_info(
+                &timeline,
+                include_non_incremental_logical_size,
+                timeline_ctx.as_ref(),
+            )
+            .await
+            .context("Failed to convert tenant timeline {timeline_id} into the local one: {e:?}")
+            .map_err(ApiError::InternalServerError)?;
 
             response_data.push(timeline_info);
         }
@@ -270,19 +293,26 @@ async fn timeline_detail_handler(request: Request<Body>) -> Result<Response<Body
         query_param_present(&request, "include-non-incremental-logical-size");
     check_permission(&request, Some(tenant_id))?;
 
+    let top_ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
     let timeline_info = async {
-        let tenant = mgr::get_tenant(tenant_id, true)
+        let (tenant, tenant_ctx) = mgr::get_active_tenant(tenant_id, &top_ctx)
             .await
             .map_err(ApiError::NotFound)?;
 
         let timeline = tenant
-            .get_timeline(timeline_id, false)
+            .get_timeline(timeline_id)
             .map_err(ApiError::NotFound)?;
+        let timeline_ctx = timeline.get_context(&tenant_ctx).ok();
 
-        let timeline_info = build_timeline_info(&timeline, include_non_incremental_logical_size)
-            .await
-            .context("Failed to get local timeline info: {e:#}")
-            .map_err(ApiError::InternalServerError)?;
+        let timeline_info = build_timeline_info(
+            &timeline,
+            include_non_incremental_logical_size,
+            timeline_ctx.as_ref(),
+        )
+        .await
+        .context("Failed to get local timeline info: {e:#}")
+        .map_err(ApiError::InternalServerError)?;
 
         Ok::<_, ApiError>(timeline_info)
     }
@@ -303,12 +333,17 @@ async fn get_lsn_by_timestamp_handler(request: Request<Body>) -> Result<Response
         .map_err(ApiError::BadRequest)?;
     let timestamp_pg = postgres_ffi::to_pg_timestamp(timestamp);
 
-    let timeline = mgr::get_tenant(tenant_id, true)
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
         .await
-        .and_then(|tenant| tenant.get_timeline(timeline_id, true))
+        .map_err(ApiError::NotFound)?;
+
+    let (timeline, ctx) = tenant
+        .get_active_timeline(timeline_id, &ctx)
         .map_err(ApiError::NotFound)?;
     let result = timeline
-        .find_lsn_for_timestamp(timestamp_pg)
+        .find_lsn_for_timestamp(timestamp_pg, &ctx)
         .await
         .map_err(apierror_from_prerror)?;
 
@@ -350,7 +385,10 @@ async fn timeline_delete_handler(request: Request<Body>) -> Result<Response<Body
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    mgr::delete_timeline(tenant_id, timeline_id)
+    // deleting shouldn't require downloading anything
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Warn);
+
+    mgr::delete_timeline(tenant_id, timeline_id, &ctx)
         .instrument(info_span!("timeline_delete", tenant = %tenant_id, timeline = %timeline_id))
         .await
         // FIXME: Errors from `delete_timeline` can occur for a number of reasons, incuding both
@@ -428,8 +466,10 @@ async fn tenant_status(request: Request<Body>) -> Result<Response<Body>, ApiErro
     let tenant_id: TenantId = parse_request_param(&request, "tenant_id")?;
     check_permission(&request, Some(tenant_id))?;
 
+    let mut _req_ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
     let tenant_info = async {
-        let tenant = mgr::get_tenant(tenant_id, false).await?;
+        let tenant = mgr::get_tenant(tenant_id).await?;
 
         // Calculate total physical size of all timelines
         let mut current_physical_size = 0;
@@ -456,13 +496,15 @@ async fn tenant_size_handler(request: Request<Body>) -> Result<Response<Body>, A
     let tenant_id: TenantId = parse_request_param(&request, "tenant_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let tenant = mgr::get_tenant(tenant_id, true)
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
         .await
         .map_err(ApiError::InternalServerError)?;
 
     // this can be long operation, it currently is not backed by any request coalescing or similar
     let inputs = tenant
-        .gather_size_inputs()
+        .gather_size_inputs(&ctx)
         .await
         .map_err(ApiError::InternalServerError)?;
 
@@ -505,6 +547,8 @@ fn bad_duration<'a>(field_name: &'static str, value: &'a str) -> impl 'a + Fn()
 async fn tenant_create_handler(mut request: Request<Body>) -> Result<Response<Body>, ApiError> {
     check_permission(&request, None)?;
 
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
     let request_data: TenantCreateRequest = json_request(&mut request).await?;
 
     let mut tenant_conf = TenantConfOpt::default();
@@ -593,7 +637,7 @@ async fn tenant_create_handler(mut request: Request<Body>) -> Result<Response<Bo
         Some(tenant) => {
             // We created the tenant. Existing API semantics are that the tenant
             // is Active when this function returns.
-            if let res @ Err(_) = tenant.wait_to_become_active().await {
+            if let res @ Err(_) = tenant.wait_to_become_active(ctx).await {
                 // This shouldn't happen because we just created the tenant directory
                 // in tenant::mgr::create_tenant, and there aren't any remote timelines
                 // to load, so, nothing can really fail during load.
@@ -617,6 +661,8 @@ async fn tenant_config_handler(mut request: Request<Body>) -> Result<Response<Bo
     let tenant_id = request_data.tenant_id;
     check_permission(&request, Some(tenant_id))?;
 
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
     let mut tenant_conf: TenantConfOpt = Default::default();
     if let Some(gc_period) = request_data.gc_period {
         tenant_conf.gc_period = Some(
@@ -679,7 +725,7 @@ async fn tenant_config_handler(mut request: Request<Body>) -> Result<Response<Bo
     }
 
     let state = get_state(&request);
-    mgr::update_tenant_config(state.conf, tenant_conf, tenant_id)
+    mgr::update_tenant_config(state.conf, tenant_conf, tenant_id, &ctx)
         .instrument(info_span!("tenant_config", tenant = ?tenant_id))
         .await
         // FIXME: `update_tenant_config` can fail because of both user and internal errors.
@@ -731,11 +777,21 @@ async fn timeline_gc_handler(mut request: Request<Body>) -> Result<Response<Body
 
     let gc_req: TimelineGcRequest = json_request(&mut request).await?;
 
-    let wait_task_done = mgr::immediate_gc(tenant_id, timeline_id, gc_req).await?;
-    let gc_result = wait_task_done
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
+        .await
+        .map_err(ApiError::NotFound)?;
+
+    let gc_horizon = gc_req.gc_horizon.unwrap_or_else(|| tenant.get_gc_horizon());
+    // Use tenant's pitr setting
+    let pitr = tenant.get_pitr_interval();
+
+    fail::fail_point!("immediate_gc_task_pre");
+    let gc_result = tenant
+        .gc_iteration(Some(timeline_id), gc_horizon, pitr, &ctx)
+        .instrument(info_span!("manual_gc", tenant = %tenant_id, timeline = %timeline_id))
         .await
-        .context("wait for gc task")
-        .map_err(ApiError::InternalServerError)?
         .map_err(ApiError::InternalServerError)?;
 
     json_response(StatusCode::OK, gc_result)
@@ -748,16 +804,19 @@ async fn timeline_compact_handler(request: Request<Body>) -> Result<Response<Bod
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let result_receiver = mgr::immediate_compact(tenant_id, timeline_id)
-        .await
-        .context("spawn compaction task")
-        .map_err(ApiError::InternalServerError)?;
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
 
-    let result: anyhow::Result<()> = result_receiver
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
+        .await
+        .map_err(ApiError::NotFound)?;
+    let (timeline, ctx) = tenant
+        .get_active_timeline(timeline_id, &ctx)
+        .map_err(ApiError::NotFound)?;
+    timeline
+        .compact(&ctx)
+        .instrument(info_span!("manual_compact", tenant = %tenant_id, timeline = %timeline_id))
         .await
-        .context("receive compaction result")
         .map_err(ApiError::InternalServerError)?;
-    result.map_err(ApiError::InternalServerError)?;
 
     json_response(StatusCode::OK, ())
 }
@@ -769,18 +828,21 @@ async fn timeline_checkpoint_handler(request: Request<Body>) -> Result<Response<
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let tenant = mgr::get_tenant(tenant_id, true)
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
         .await
         .map_err(ApiError::NotFound)?;
-    let timeline = tenant
-        .get_timeline(timeline_id, true)
+    let (timeline, ctx) = tenant
+        .get_active_timeline(timeline_id, &ctx)
         .map_err(ApiError::NotFound)?;
     timeline
         .freeze_and_flush()
         .await
         .map_err(ApiError::InternalServerError)?;
     timeline
-        .compact()
+        .compact(&ctx)
+        .instrument(info_span!("manual_compact", tenant = %tenant_id, timeline = %timeline_id))
         .await
         .map_err(ApiError::InternalServerError)?;
 
@@ -794,13 +856,15 @@ async fn timeline_download_remote_layers_handler_post(
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let tenant = mgr::get_tenant(tenant_id, true)
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
         .await
         .map_err(ApiError::NotFound)?;
-    let timeline = tenant
-        .get_timeline(timeline_id, true)
+    let (timeline, ctx) = tenant
+        .get_active_timeline(timeline_id, &ctx)
         .map_err(ApiError::NotFound)?;
-    match timeline.spawn_download_all_remote_layers().await {
+    match timeline.spawn_download_all_remote_layers(&ctx).await {
         Ok(st) => json_response(StatusCode::ACCEPTED, st),
         Err(st) => json_response(StatusCode::CONFLICT, st),
     }
@@ -813,11 +877,13 @@ async fn timeline_download_remote_layers_handler_get(
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let tenant = mgr::get_tenant(tenant_id, true)
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+
+    let (tenant, ctx) = mgr::get_active_tenant(tenant_id, &ctx)
         .await
         .map_err(ApiError::NotFound)?;
-    let timeline = tenant
-        .get_timeline(timeline_id, true)
+    let (timeline, _ctx) = tenant
+        .get_active_timeline(timeline_id, &ctx)
         .map_err(ApiError::NotFound)?;
     let info = timeline
         .get_download_all_remote_layers_task_info()

pageserver/src/import_datadir.rs

@@ -13,7 +13,7 @@ use tracing::*;
 use walkdir::WalkDir;
 
 use crate::pgdatadir_mapping::*;
-use crate::tenant::Timeline;
+use crate::tenant::{Timeline, TimelineRequestContext};
 use crate::walingest::WalIngest;
 use crate::walrecord::DecodedWALRecord;
 use pageserver_api::reltag::{RelTag, SlruKind};
@@ -47,6 +47,7 @@ pub async fn import_timeline_from_postgres_datadir(
     tline: &Timeline,
     pgdata_path: &Path,
     pgdata_lsn: Lsn,
+    ctx: &TimelineRequestContext,
 ) -> Result<()> {
     let mut pg_control: Option<ControlFileData> = None;
 
@@ -69,7 +70,7 @@ pub async fn import_timeline_from_postgres_datadir(
             let mut file = tokio::fs::File::open(absolute_path).await?;
             let len = metadata.len() as usize;
             if let Some(control_file) =
-                import_file(&mut modification, relative_path, &mut file, len).await?
+                import_file(&mut modification, relative_path, &mut file, len, ctx).await?
             {
                 pg_control = Some(control_file);
             }
@@ -99,6 +100,7 @@ pub async fn import_timeline_from_postgres_datadir(
         tline,
         Lsn(pg_control.checkPointCopy.redo),
         pgdata_lsn,
+        ctx,
     )
     .await?;
 
@@ -113,6 +115,7 @@ async fn import_rel(
     dboid: Oid,
     reader: &mut (impl AsyncRead + Send + Sync + Unpin),
     len: usize,
+    ctx: &TimelineRequestContext,
 ) -> anyhow::Result<()> {
     // Does it look like a relation file?
     trace!("importing rel file {}", path.display());
@@ -147,7 +150,10 @@ async fn import_rel(
     // FIXME: use proper error type for this, instead of parsing the error message.
     // Or better yet, keep track of which relations we've already created
     // https://github.com/neondatabase/neon/issues/3309
-    if let Err(e) = modification.put_rel_creation(rel, nblocks as u32).await {
+    if let Err(e) = modification
+        .put_rel_creation(rel, nblocks as u32, ctx)
+        .await
+    {
         if e.to_string().contains("already exists") {
             debug!("relation {} already exists. we must be extending it", rel);
         } else {
@@ -182,7 +188,7 @@ async fn import_rel(
     //
     // If we process rel segments out of order,
     // put_rel_extend will skip the update.
-    modification.put_rel_extend(rel, blknum).await?;
+    modification.put_rel_extend(rel, blknum, ctx).await?;
 
     Ok(())
 }
@@ -195,6 +201,7 @@ async fn import_slru(
     path: &Path,
     reader: &mut (impl AsyncRead + Send + Sync + Unpin),
     len: usize,
+    ctx: &TimelineRequestContext,
 ) -> anyhow::Result<()> {
     info!("importing slru file {path:?}");
 
@@ -211,7 +218,7 @@ async fn import_slru(
     ensure!(nblocks <= pg_constants::SLRU_PAGES_PER_SEGMENT as usize);
 
     modification
-        .put_slru_segment_creation(slru, segno, nblocks as u32)
+        .put_slru_segment_creation(slru, segno, nblocks as u32, ctx)
         .await?;
 
     let mut rpageno = 0;
@@ -252,15 +259,15 @@ async fn import_wal(
     tline: &Timeline,
     startpoint: Lsn,
     endpoint: Lsn,
+    ctx: &TimelineRequestContext,
 ) -> anyhow::Result<()> {
-    use std::io::Read;
     let mut waldecoder = WalStreamDecoder::new(startpoint, tline.pg_version);
 
     let mut segno = startpoint.segment_number(WAL_SEGMENT_SIZE);
     let mut offset = startpoint.segment_offset(WAL_SEGMENT_SIZE);
     let mut last_lsn = startpoint;
 
-    let mut walingest = WalIngest::new(tline, startpoint).await?;
+    let mut walingest = WalIngest::new(tline, startpoint, ctx).await?;
 
     while last_lsn <= endpoint {
         // FIXME: assume postgresql tli 1 for now
@@ -283,6 +290,7 @@ async fn import_wal(
             file.seek(std::io::SeekFrom::Start(offset as u64))?;
         }
 
+        use std::io::Read;
         let nread = file.read_to_end(&mut buf)?;
         if nread != WAL_SEGMENT_SIZE - offset {
             // Maybe allow this for .partial files?
@@ -297,7 +305,7 @@ async fn import_wal(
         while last_lsn <= endpoint {
             if let Some((lsn, recdata)) = waldecoder.poll_decode()? {
                 walingest
-                    .ingest_record(recdata, lsn, &mut modification, &mut decoded)
+                    .ingest_record(recdata, lsn, &mut modification, &mut decoded, ctx)
                     .await?;
                 last_lsn = lsn;
 
@@ -326,6 +334,7 @@ pub async fn import_basebackup_from_tar(
     tline: &Timeline,
     reader: &mut (impl AsyncRead + Send + Sync + Unpin),
     base_lsn: Lsn,
+    ctx: &TimelineRequestContext,
 ) -> Result<()> {
     info!("importing base at {base_lsn}");
     let mut modification = tline.begin_modification(base_lsn);
@@ -344,7 +353,7 @@ pub async fn import_basebackup_from_tar(
         match header.entry_type() {
             tokio_tar::EntryType::Regular => {
                 if let Some(res) =
-                    import_file(&mut modification, file_path.as_ref(), &mut entry, len).await?
+                    import_file(&mut modification, file_path.as_ref(), &mut entry, len, ctx).await?
                 {
                     // We found the pg_control file.
                     pg_control = Some(res);
@@ -376,13 +385,14 @@ pub async fn import_wal_from_tar(
     reader: &mut (impl AsyncRead + Send + Sync + Unpin),
     start_lsn: Lsn,
     end_lsn: Lsn,
+    ctx: &TimelineRequestContext,
 ) -> Result<()> {
     // Set up walingest mutable state
     let mut waldecoder = WalStreamDecoder::new(start_lsn, tline.pg_version);
     let mut segno = start_lsn.segment_number(WAL_SEGMENT_SIZE);
     let mut offset = start_lsn.segment_offset(WAL_SEGMENT_SIZE);
     let mut last_lsn = start_lsn;
-    let mut walingest = WalIngest::new(tline, start_lsn).await?;
+    let mut walingest = WalIngest::new(tline, start_lsn, ctx).await?;
 
     // Ingest wal until end_lsn
     info!("importing wal until {}", end_lsn);
@@ -431,7 +441,7 @@ pub async fn import_wal_from_tar(
         while last_lsn <= end_lsn {
             if let Some((lsn, recdata)) = waldecoder.poll_decode()? {
                 walingest
-                    .ingest_record(recdata, lsn, &mut modification, &mut decoded)
+                    .ingest_record(recdata, lsn, &mut modification, &mut decoded, ctx)
                     .await?;
                 last_lsn = lsn;
 
@@ -466,6 +476,7 @@ async fn import_file(
     file_path: &Path,
     reader: &mut (impl AsyncRead + Send + Sync + Unpin),
     len: usize,
+    ctx: &TimelineRequestContext,
 ) -> Result<Option<ControlFileData>> {
     let file_name = match file_path.file_name() {
         Some(name) => name.to_string_lossy(),
@@ -498,14 +509,16 @@ async fn import_file(
             }
             "pg_filenode.map" => {
                 let bytes = read_all_bytes(reader).await?;
-                modification.put_relmap_file(spcnode, dbnode, bytes).await?;
+                modification
+                    .put_relmap_file(spcnode, dbnode, bytes, ctx)
+                    .await?;
                 debug!("imported relmap file")
             }
             "PG_VERSION" => {
                 debug!("ignored PG_VERSION file");
             }
             _ => {
-                import_rel(modification, file_path, spcnode, dbnode, reader, len).await?;
+                import_rel(modification, file_path, spcnode, dbnode, reader, len, ctx).await?;
                 debug!("imported rel creation");
             }
         }
@@ -521,38 +534,40 @@ async fn import_file(
         match file_name.as_ref() {
             "pg_filenode.map" => {
                 let bytes = read_all_bytes(reader).await?;
-                modification.put_relmap_file(spcnode, dbnode, bytes).await?;
+                modification
+                    .put_relmap_file(spcnode, dbnode, bytes, ctx)
+                    .await?;
                 debug!("imported relmap file")
             }
             "PG_VERSION" => {
                 debug!("ignored PG_VERSION file");
             }
             _ => {
-                import_rel(modification, file_path, spcnode, dbnode, reader, len).await?;
+                import_rel(modification, file_path, spcnode, dbnode, reader, len, ctx).await?;
                 debug!("imported rel creation");
             }
         }
     } else if file_path.starts_with("pg_xact") {
         let slru = SlruKind::Clog;
 
-        import_slru(modification, slru, file_path, reader, len).await?;
+        import_slru(modification, slru, file_path, reader, len, ctx).await?;
         debug!("imported clog slru");
     } else if file_path.starts_with("pg_multixact/offsets") {
         let slru = SlruKind::MultiXactOffsets;
 
-        import_slru(modification, slru, file_path, reader, len).await?;
+        import_slru(modification, slru, file_path, reader, len, ctx).await?;
         debug!("imported multixact offsets slru");
     } else if file_path.starts_with("pg_multixact/members") {
         let slru = SlruKind::MultiXactMembers;
 
-        import_slru(modification, slru, file_path, reader, len).await?;
+        import_slru(modification, slru, file_path, reader, len, ctx).await?;
         debug!("imported multixact members slru");
     } else if file_path.starts_with("pg_twophase") {
         let xid = u32::from_str_radix(file_name.as_ref(), 16)?;
 
         let bytes = read_all_bytes(reader).await?;
         modification
-            .put_twophase_file(xid, Bytes::copy_from_slice(&bytes[..]))
+            .put_twophase_file(xid, Bytes::copy_from_slice(&bytes[..]), ctx)
             .await?;
         debug!("imported twophase file");
     } else if file_path.starts_with("pg_wal") {

pageserver/src/lib.rs

@@ -2,6 +2,7 @@ mod auth;
 pub mod basebackup;
 pub mod config;
 pub mod consumption_metrics;
+pub mod context;
 pub mod http;
 pub mod import_datadir;
 pub mod keyspace;
@@ -21,7 +22,6 @@ pub mod walredo;
 
 use std::path::Path;
 
-use crate::task_mgr::TaskKind;
 use tracing::info;
 
 /// Current storage format version
@@ -41,35 +41,6 @@ pub const DELTA_FILE_MAGIC: u16 = 0x5A61;
 
 static ZERO_PAGE: bytes::Bytes = bytes::Bytes::from_static(&[0u8; 8192]);
 
-pub async fn shutdown_pageserver(exit_code: i32) {
-    // Shut down the libpq endpoint task. This prevents new connections from
-    // being accepted.
-    task_mgr::shutdown_tasks(Some(TaskKind::LibpqEndpointListener), None, None).await;
-
-    // Shut down any page service tasks.
-    task_mgr::shutdown_tasks(Some(TaskKind::PageRequestHandler), None, None).await;
-
-    // Shut down all the tenants. This flushes everything to disk and kills
-    // the checkpoint and GC tasks.
-    tenant::mgr::shutdown_all_tenants().await;
-
-    // Stop syncing with remote storage.
-    //
-    // FIXME: Does this wait for the sync tasks to finish syncing what's queued up?
-    // Should it?
-    task_mgr::shutdown_tasks(Some(TaskKind::RemoteUploadTask), None, None).await;
-
-    // Shut down the HTTP endpoint last, so that you can still check the server's
-    // status while it's shutting down.
-    // FIXME: We should probably stop accepting commands like attach/detach earlier.
-    task_mgr::shutdown_tasks(Some(TaskKind::HttpEndpointListener), None, None).await;
-
-    // There should be nothing left, but let's be sure
-    task_mgr::shutdown_tasks(None, None, None).await;
-    info!("Shut down successfully completed");
-    std::process::exit(exit_code);
-}
-
 const DEFAULT_BASE_BACKOFF_SECONDS: f64 = 0.1;
 const DEFAULT_MAX_BACKOFF_SECONDS: f64 = 3.0;
 

pageserver/src/page_service.rs

@@ -43,24 +43,27 @@ use utils::{
 use crate::auth::check_permission;
 use crate::basebackup;
 use crate::config::PageServerConf;
+use crate::context::{DownloadBehavior, RequestContext, TaskKind};
 use crate::import_datadir::import_wal_from_tar;
 use crate::metrics::{LIVE_CONNECTIONS_COUNT, SMGR_QUERY_TIME};
 use crate::task_mgr;
-use crate::task_mgr::TaskKind;
 use crate::tenant::mgr;
-use crate::tenant::{Tenant, Timeline};
+use crate::tenant::{Tenant, TenantRequestContext, Timeline, TimelineRequestContext};
 use crate::trace::Tracer;
 
 use postgres_ffi::pg_constants::DEFAULTTABLESPACE_OID;
 use postgres_ffi::BLCKSZ;
 
-fn copyin_stream(pgb: &mut PostgresBackend) -> impl Stream<Item = io::Result<Bytes>> + '_ {
+fn copyin_stream<'a>(
+    pgb: &'a mut PostgresBackend,
+    ctx: &'a RequestContext,
+) -> impl Stream<Item = io::Result<Bytes>> + 'a {
     async_stream::try_stream! {
         loop {
             let msg = tokio::select! {
                 biased;
 
-                _ = task_mgr::shutdown_watcher() => {
+                _ = ctx.cancelled() => {
                     // We were requested to shut down.
                     let msg = format!("pageserver is shutting down");
                     let _ = pgb.write_message(&BeMessage::ErrorResponse(&msg, None));
@@ -123,6 +126,7 @@ pub async fn libpq_listener_main(
     auth: Option<Arc<JwtAuth>>,
     listener: TcpListener,
     auth_type: AuthType,
+    listener_ctx: RequestContext,
 ) -> anyhow::Result<()> {
     listener.set_nonblocking(true)?;
     let tokio_listener = tokio::net::TcpListener::from_std(listener)?;
@@ -131,8 +135,9 @@ pub async fn libpq_listener_main(
     while let Some(res) = tokio::select! {
         biased;
 
-        _ = task_mgr::shutdown_watcher() => {
+        _ = listener_ctx.cancelled() => {
             // We were requested to shut down.
+            info!("libpq listener shutting down");
             None
         }
 
@@ -146,18 +151,33 @@ pub async fn libpq_listener_main(
                 debug!("accepted connection from {}", peer_addr);
                 let local_auth = auth.clone();
 
+                let connection_ctx = RequestContext::with_parent(
+                    TaskKind::PageRequestHandler,
+                    DownloadBehavior::Download,
+                    &listener_ctx,
+                );
+
                 // PageRequestHandler tasks are not associated with any particular
                 // timeline in the task manager. In practice most connections will
                 // only deal with a particular timeline, but we don't know which one
                 // yet.
                 task_mgr::spawn(
                     &tokio::runtime::Handle::current(),
-                    TaskKind::PageRequestHandler,
-                    None,
-                    None,
                     "serving compute connection task",
                     false,
-                    page_service_conn_main(conf, local_auth, socket, auth_type),
+                    async move {
+                        if let Err(err) = page_service_conn_main(
+                            conf,
+                            local_auth,
+                            socket,
+                            auth_type,
+                            connection_ctx,
+                        )
+                        .await
+                        {
+                            error!("connection handler exited with error: {err:?}");
+                        }
+                    },
                 );
             }
             Err(err) => {
@@ -177,6 +197,7 @@ async fn page_service_conn_main(
     auth: Option<Arc<JwtAuth>>,
     socket: tokio::net::TcpStream,
     auth_type: AuthType,
+    connection_ctx: RequestContext,
 ) -> anyhow::Result<()> {
     // Immediately increment the gauge, then create a job to decrement it on task exit.
     // One of the pros of `defer!` is that this will *most probably*
@@ -191,11 +212,13 @@ async fn page_service_conn_main(
         .set_nodelay(true)
         .context("could not set TCP_NODELAY")?;
 
-    let mut conn_handler = PageServerHandler::new(conf, auth);
+    let cancellation_token = connection_ctx.cancellation_token().clone();
+
+    let mut conn_handler = PageServerHandler::new(conf, auth, connection_ctx);
     let pgbackend = PostgresBackend::new(socket, auth_type, None)?;
 
     let result = pgbackend
-        .run(&mut conn_handler, task_mgr::shutdown_watcher)
+        .run(&mut conn_handler, || cancellation_token.cancelled())
         .await;
     match result {
         Ok(()) => {
@@ -255,30 +278,34 @@ struct PageServerHandler {
     _conf: &'static PageServerConf,
     auth: Option<Arc<JwtAuth>>,
     claims: Option<Claims>,
+
+    connection_ctx: RequestContext,
 }
 
 impl PageServerHandler {
-    pub fn new(conf: &'static PageServerConf, auth: Option<Arc<JwtAuth>>) -> Self {
+    pub fn new(
+        conf: &'static PageServerConf,
+        auth: Option<Arc<JwtAuth>>,
+        connection_ctx: RequestContext,
+    ) -> Self {
         PageServerHandler {
             _conf: conf,
             auth,
             claims: None,
+            connection_ctx,
         }
     }
 
     #[instrument(skip(self, pgb))]
     async fn handle_pagerequests(
-        &self,
+        &mut self,
         pgb: &mut PostgresBackend,
         tenant_id: TenantId,
         timeline_id: TimelineId,
     ) -> anyhow::Result<()> {
-        // NOTE: pagerequests handler exits when connection is closed,
-        //       so there is no need to reset the association
-        task_mgr::associate_with(Some(tenant_id), Some(timeline_id));
+        let (tenant, ctx) = get_active_tenant_with_timeout(tenant_id, &self.connection_ctx).await?;
 
         // Make request tracer if needed
-        let tenant = get_active_tenant_with_timeout(tenant_id).await?;
         let mut tracer = if tenant.get_trace_read_requests() {
             let connection_id = ConnectionId::generate();
             let path = tenant
@@ -290,7 +317,7 @@ impl PageServerHandler {
         };
 
         // Check that the timeline exists
-        let timeline = tenant.get_timeline(timeline_id, true)?;
+        let (timeline, ctx) = tenant.get_active_timeline(timeline_id, &ctx)?;
 
         // switch client to COPYBOTH
         pgb.write_message(&BeMessage::CopyBothResponse)?;
@@ -302,7 +329,7 @@ impl PageServerHandler {
             let msg = tokio::select! {
                 biased;
 
-                _ = task_mgr::shutdown_watcher() => {
+                _ = ctx.cancelled() => {
                     // We were requested to shut down.
                     info!("shutdown request received in page handler");
                     break;
@@ -329,22 +356,27 @@ impl PageServerHandler {
 
             let neon_fe_msg = PagestreamFeMessage::parse(&mut copy_data_bytes.reader())?;
 
+            // TODO: We could create a new per-request context here, with unique ID.
+            // Currently we use the same per-timeline context for all requests
+
             let response = match neon_fe_msg {
                 PagestreamFeMessage::Exists(req) => {
                     let _timer = metrics.get_rel_exists.start_timer();
-                    self.handle_get_rel_exists_request(&timeline, &req).await
+                    self.handle_get_rel_exists_request(&timeline, &req, &ctx)
+                        .await
                 }
                 PagestreamFeMessage::Nblocks(req) => {
                     let _timer = metrics.get_rel_size.start_timer();
-                    self.handle_get_nblocks_request(&timeline, &req).await
+                    self.handle_get_nblocks_request(&timeline, &req, &ctx).await
                 }
                 PagestreamFeMessage::GetPage(req) => {
                     let _timer = metrics.get_page_at_lsn.start_timer();
-                    self.handle_get_page_at_lsn_request(&timeline, &req).await
+                    self.handle_get_page_at_lsn_request(&timeline, &req, &ctx)
+                        .await
                 }
                 PagestreamFeMessage::DbSize(req) => {
                     let _timer = metrics.get_db_size.start_timer();
-                    self.handle_db_size_request(&timeline, &req).await
+                    self.handle_db_size_request(&timeline, &req, &ctx).await
                 }
             };
 
@@ -365,7 +397,7 @@ impl PageServerHandler {
 
     #[instrument(skip(self, pgb))]
     async fn handle_import_basebackup(
-        &self,
+        &mut self,
         pgb: &mut PostgresBackend,
         tenant_id: TenantId,
         timeline_id: TimelineId,
@@ -373,11 +405,12 @@ impl PageServerHandler {
         _end_lsn: Lsn,
         pg_version: u32,
     ) -> Result<(), QueryError> {
-        task_mgr::associate_with(Some(tenant_id), Some(timeline_id));
         // Create empty timeline
         info!("creating new timeline");
-        let tenant = get_active_tenant_with_timeout(tenant_id).await?;
-        let timeline = tenant.create_empty_timeline(timeline_id, base_lsn, pg_version)?;
+        let (tenant, tenant_ctx) =
+            get_active_tenant_with_timeout(tenant_id, &self.connection_ctx).await?;
+        let (timeline, ctx) =
+            tenant.create_empty_timeline(timeline_id, base_lsn, pg_version, &tenant_ctx)?;
 
         // TODO mark timeline as not ready until it reaches end_lsn.
         // We might have some wal to import as well, and we should prevent compute
@@ -394,9 +427,9 @@ impl PageServerHandler {
         pgb.write_message(&BeMessage::CopyInResponse)?;
         pgb.flush().await?;
 
-        let mut copyin_stream = Box::pin(copyin_stream(pgb));
+        let mut copyin_stream = Box::pin(copyin_stream(pgb, &ctx));
         timeline
-            .import_basebackup_from_tar(&mut copyin_stream, base_lsn)
+            .import_basebackup_from_tar(&mut copyin_stream, base_lsn, &ctx)
             .await?;
 
         // Drain the rest of the Copy data
@@ -420,16 +453,15 @@ impl PageServerHandler {
 
     #[instrument(skip(self, pgb))]
     async fn handle_import_wal(
-        &self,
+        &mut self,
         pgb: &mut PostgresBackend,
         tenant_id: TenantId,
         timeline_id: TimelineId,
         start_lsn: Lsn,
         end_lsn: Lsn,
     ) -> Result<(), QueryError> {
-        task_mgr::associate_with(Some(tenant_id), Some(timeline_id));
-
-        let timeline = get_active_timeline_with_timeout(tenant_id, timeline_id).await?;
+        let (timeline, ctx) =
+            get_active_timeline_with_timeout(tenant_id, timeline_id, &self.connection_ctx).await?;
         let last_record_lsn = timeline.get_last_record_lsn();
         if last_record_lsn != start_lsn {
             return Err(QueryError::Other(
@@ -444,9 +476,9 @@ impl PageServerHandler {
         info!("importing wal");
         pgb.write_message(&BeMessage::CopyInResponse)?;
         pgb.flush().await?;
-        let mut copyin_stream = Box::pin(copyin_stream(pgb));
+        let mut copyin_stream = Box::pin(copyin_stream(pgb, &ctx));
         let mut reader = tokio_util::io::StreamReader::new(&mut copyin_stream);
-        import_wal_from_tar(&timeline, &mut reader, start_lsn, end_lsn).await?;
+        import_wal_from_tar(&timeline, &mut reader, start_lsn, end_lsn, &ctx).await?;
         info!("wal import complete");
 
         // Drain the rest of the Copy data
@@ -492,6 +524,7 @@ impl PageServerHandler {
         mut lsn: Lsn,
         latest: bool,
         latest_gc_cutoff_lsn: &RcuReadGuard<Lsn>,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<Lsn> {
         if latest {
             // Latest page version was requested. If LSN is given, it is a hint
@@ -515,7 +548,7 @@ impl PageServerHandler {
             if lsn <= last_record_lsn {
                 lsn = last_record_lsn;
             } else {
-                timeline.wait_lsn(lsn).await?;
+                timeline.wait_lsn(lsn, ctx).await?;
                 // Since we waited for 'lsn' to arrive, that is now the last
                 // record LSN. (Or close enough for our purposes; the
                 // last-record LSN can advance immediately after we return
@@ -525,7 +558,7 @@ impl PageServerHandler {
             if lsn == Lsn(0) {
                 anyhow::bail!("invalid LSN(0) in request");
             }
-            timeline.wait_lsn(lsn).await?;
+            timeline.wait_lsn(lsn, ctx).await?;
         }
         anyhow::ensure!(
             lsn >= **latest_gc_cutoff_lsn,
@@ -535,52 +568,60 @@ impl PageServerHandler {
         Ok(lsn)
     }
 
-    #[instrument(skip(self, timeline, req), fields(rel = %req.rel, req_lsn = %req.lsn))]
+    #[instrument(skip(self, timeline, req, ctx), fields(rel = %req.rel, req_lsn = %req.lsn))]
     async fn handle_get_rel_exists_request(
         &self,
         timeline: &Timeline,
         req: &PagestreamExistsRequest,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<PagestreamBeMessage> {
         let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn)
-            .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;
 
-        let exists = timeline.get_rel_exists(req.rel, lsn, req.latest).await?;
+        let exists = timeline
+            .get_rel_exists(req.rel, lsn, req.latest, ctx)
+            .await?;
 
         Ok(PagestreamBeMessage::Exists(PagestreamExistsResponse {
             exists,
         }))
     }
 
-    #[instrument(skip(self, timeline, req), fields(rel = %req.rel, req_lsn = %req.lsn))]
+    #[instrument(skip(self, timeline, req, ctx), fields(rel = %req.rel, req_lsn = %req.lsn))]
     async fn handle_get_nblocks_request(
         &self,
         timeline: &Timeline,
         req: &PagestreamNblocksRequest,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<PagestreamBeMessage> {
         let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn)
-            .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;
 
-        let n_blocks = timeline.get_rel_size(req.rel, lsn, req.latest).await?;
+        let n_blocks = timeline.get_rel_size(req.rel, lsn, req.latest, ctx).await?;
 
         Ok(PagestreamBeMessage::Nblocks(PagestreamNblocksResponse {
             n_blocks,
         }))
     }
 
-    #[instrument(skip(self, timeline, req), fields(dbnode = %req.dbnode, req_lsn = %req.lsn))]
+    #[instrument(skip(self, timeline, req, ctx), fields(dbnode = %req.dbnode, req_lsn = %req.lsn))]
     async fn handle_db_size_request(
         &self,
         timeline: &Timeline,
         req: &PagestreamDbSizeRequest,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<PagestreamBeMessage> {
         let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn)
-            .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;
 
         let total_blocks = timeline
-            .get_db_size(DEFAULTTABLESPACE_OID, req.dbnode, lsn, req.latest)
+            .get_db_size(DEFAULTTABLESPACE_OID, req.dbnode, lsn, req.latest, ctx)
             .await?;
         let db_size = total_blocks as i64 * BLCKSZ as i64;
 
@@ -589,15 +630,17 @@ impl PageServerHandler {
         }))
     }
 
-    #[instrument(skip(self, timeline, req), fields(rel = %req.rel, blkno = %req.blkno, req_lsn = %req.lsn))]
+    #[instrument(skip(self, timeline, req, ctx), fields(rel = %req.rel, blkno = %req.blkno, req_lsn = %req.lsn))]
     async fn handle_get_page_at_lsn_request(
         &self,
         timeline: &Timeline,
         req: &PagestreamGetPageRequest,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<PagestreamBeMessage> {
         let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
-        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn)
-            .await?;
+        let lsn =
+            Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn, ctx)
+                .await?;
         /*
         // Add a 1s delay to some requests. The delay helps the requests to
         // hit the race condition from github issue #1047 more easily.
@@ -608,7 +651,7 @@ impl PageServerHandler {
         */
 
         let page = timeline
-            .get_rel_page_at_lsn(req.rel, req.blkno, lsn, req.latest)
+            .get_rel_page_at_lsn(req.rel, req.blkno, lsn, req.latest, ctx)
             .await?;
 
         Ok(PagestreamBeMessage::GetPage(PagestreamGetPageResponse {
@@ -618,7 +661,7 @@ impl PageServerHandler {
 
     #[instrument(skip(self, pgb))]
     async fn handle_basebackup_request(
-        &self,
+        &mut self,
         pgb: &mut PostgresBackend,
         tenant_id: TenantId,
         timeline_id: TimelineId,
@@ -627,12 +670,14 @@ impl PageServerHandler {
         full_backup: bool,
     ) -> anyhow::Result<()> {
         // check that the timeline exists
-        let timeline = get_active_timeline_with_timeout(tenant_id, timeline_id).await?;
+        let (timeline, ctx) =
+            get_active_timeline_with_timeout(tenant_id, timeline_id, &self.connection_ctx).await?;
+
         let latest_gc_cutoff_lsn = timeline.get_latest_gc_cutoff_lsn();
         if let Some(lsn) = lsn {
             // Backup was requested at a particular LSN. Wait for it to arrive.
             info!("waiting for {}", lsn);
-            timeline.wait_lsn(lsn).await?;
+            timeline.wait_lsn(lsn, &ctx).await?;
             timeline
                 .check_lsn_is_in_scope(lsn, &latest_gc_cutoff_lsn)
                 .context("invalid basebackup lsn")?;
@@ -645,8 +690,15 @@ impl PageServerHandler {
         // Send a tarball of the latest layer on the timeline
         {
             let mut writer = pgb.copyout_writer();
-            basebackup::send_basebackup_tarball(&mut writer, &timeline, lsn, prev_lsn, full_backup)
-                .await?;
+            basebackup::send_basebackup_tarball(
+                &mut writer,
+                &timeline,
+                lsn,
+                prev_lsn,
+                full_backup,
+                &ctx,
+            )
+            .await?;
         }
 
         pgb.write_message(&BeMessage::CopyDone)?;
@@ -784,7 +836,9 @@ impl postgres_backend_async::Handler for PageServerHandler {
                 .with_context(|| format!("Failed to parse timeline id from {}", params[1]))?;
 
             self.check_permission(Some(tenant_id))?;
-            let timeline = get_active_timeline_with_timeout(tenant_id, timeline_id).await?;
+            let (timeline, _ctx) =
+                get_active_timeline_with_timeout(tenant_id, timeline_id, &self.connection_ctx)
+                    .await?;
 
             let end_of_timeline = timeline.get_last_record_rlsn();
 
@@ -944,7 +998,8 @@ impl postgres_backend_async::Handler for PageServerHandler {
 
             self.check_permission(Some(tenant_id))?;
 
-            let tenant = get_active_tenant_with_timeout(tenant_id).await?;
+            let (tenant, _ctx) =
+                get_active_tenant_with_timeout(tenant_id, &self.connection_ctx).await?;
             pgb.write_message(&BeMessage::RowDescription(&[
                 RowDescriptor::int8_col(b"checkpoint_distance"),
                 RowDescriptor::int8_col(b"checkpoint_timeout"),
@@ -995,12 +1050,25 @@ impl postgres_backend_async::Handler for PageServerHandler {
 /// If the tenant is Loading, waits for it to become Active, for up to 30 s. That
 /// ensures that queries don't fail immediately after pageserver startup, because
 /// all tenants are still loading.
-async fn get_active_tenant_with_timeout(tenant_id: TenantId) -> anyhow::Result<Arc<Tenant>> {
-    let tenant = mgr::get_tenant(tenant_id, false).await?;
-    match tokio::time::timeout(Duration::from_secs(30), tenant.wait_to_become_active()).await {
-        Ok(wait_result) => wait_result
-            // no .context(), the error message is good enough and some tests depend on it
-            .map(move |()| tenant),
+async fn get_active_tenant_with_timeout(
+    tenant_id: TenantId,
+    parent_ctx: &RequestContext,
+) -> anyhow::Result<(Arc<Tenant>, TenantRequestContext)> {
+    let child_ctx = RequestContext::with_parent(
+        parent_ctx.task_kind(),
+        parent_ctx.download_behavior(),
+        parent_ctx,
+    );
+
+    let tenant = mgr::get_tenant(tenant_id).await?;
+    match tokio::time::timeout(
+        Duration::from_secs(30),
+        tenant.wait_to_become_active(child_ctx),
+    )
+    .await
+    {
+        Ok(Ok(ctx)) => Ok((tenant, ctx)),
+        Ok(Err(err)) => Err(err),
         Err(_) => anyhow::bail!("Timeout waiting for tenant {tenant_id} to become Active"),
     }
 }
@@ -1009,8 +1077,9 @@ async fn get_active_tenant_with_timeout(tenant_id: TenantId) -> anyhow::Result<A
 async fn get_active_timeline_with_timeout(
     tenant_id: TenantId,
     timeline_id: TimelineId,
-) -> anyhow::Result<Arc<Timeline>> {
-    get_active_tenant_with_timeout(tenant_id)
+    ctx: &RequestContext,
+) -> anyhow::Result<(Arc<Timeline>, TimelineRequestContext)> {
+    get_active_tenant_with_timeout(tenant_id, ctx)
         .await
-        .and_then(|tenant| tenant.get_timeline(timeline_id, true))
+        .and_then(|(tenant, ctx)| tenant.get_active_timeline(timeline_id, &ctx))
 }

pageserver/src/pgdatadir_mapping.rs

@@ -6,9 +6,9 @@
 //! walingest.rs handles a few things like implicit relation creation and extension.
 //! Clarify that)
 //!
-use super::tenant::{PageReconstructError, Timeline};
 use crate::keyspace::{KeySpace, KeySpaceAccum};
 use crate::repository::*;
+use crate::tenant::{PageReconstructError, Timeline, TimelineRequestContext};
 use crate::walrecord::NeonWalRecord;
 use anyhow::Context;
 use bytes::{Buf, Bytes};
@@ -19,7 +19,6 @@ use postgres_ffi::{Oid, TimestampTz, TransactionId};
 use serde::{Deserialize, Serialize};
 use std::collections::{hash_map, HashMap, HashSet};
 use std::ops::Range;
-use tokio_util::sync::CancellationToken;
 use tracing::{debug, trace, warn};
 use utils::{bin_ser::BeSer, lsn::Lsn};
 
@@ -34,14 +33,6 @@ pub enum LsnForTimestamp {
     NoData(Lsn),
 }
 
-#[derive(Debug, thiserror::Error)]
-pub enum CalculateLogicalSizeError {
-    #[error("cancelled")]
-    Cancelled,
-    #[error(transparent)]
-    Other(#[from] anyhow::Error),
-}
-
 ///
 /// This impl provides all the functionality to store PostgreSQL relations, SLRUs,
 /// and other special kinds of files, in a versioned key-value store. The
@@ -97,6 +88,7 @@ impl Timeline {
         blknum: BlockNumber,
         lsn: Lsn,
         latest: bool,
+        ctx: &TimelineRequestContext,
     ) -> Result<Bytes, PageReconstructError> {
         if tag.relnode == 0 {
             return Err(PageReconstructError::Other(anyhow::anyhow!(
@@ -104,7 +96,7 @@ impl Timeline {
             )));
         }
 
-        let nblocks = self.get_rel_size(tag, lsn, latest).await?;
+        let nblocks = self.get_rel_size(tag, lsn, latest, ctx).await?;
         if blknum >= nblocks {
             debug!(
                 "read beyond EOF at {} blk {} at {}, size is {}: returning all-zeros page",
@@ -114,7 +106,7 @@ impl Timeline {
         }
 
         let key = rel_block_to_key(tag, blknum);
-        self.get(key, lsn).await
+        self.get(key, lsn, ctx).await
     }
 
     // Get size of a database in blocks
@@ -124,13 +116,14 @@ impl Timeline {
         dbnode: Oid,
         lsn: Lsn,
         latest: bool,
+        ctx: &TimelineRequestContext,
     ) -> Result<usize, PageReconstructError> {
         let mut total_blocks = 0;
 
-        let rels = self.list_rels(spcnode, dbnode, lsn).await?;
+        let rels = self.list_rels(spcnode, dbnode, lsn, ctx).await?;
 
         for rel in rels {
-            let n_blocks = self.get_rel_size(rel, lsn, latest).await?;
+            let n_blocks = self.get_rel_size(rel, lsn, latest, ctx).await?;
             total_blocks += n_blocks as usize;
         }
         Ok(total_blocks)
@@ -142,6 +135,7 @@ impl Timeline {
         tag: RelTag,
         lsn: Lsn,
         latest: bool,
+        ctx: &TimelineRequestContext,
     ) -> Result<BlockNumber, PageReconstructError> {
         if tag.relnode == 0 {
             return Err(PageReconstructError::Other(anyhow::anyhow!(
@@ -154,7 +148,7 @@ impl Timeline {
         }
 
         if (tag.forknum == FSM_FORKNUM || tag.forknum == VISIBILITYMAP_FORKNUM)
-            && !self.get_rel_exists(tag, lsn, latest).await?
+            && !self.get_rel_exists(tag, lsn, latest, ctx).await?
         {
             // FIXME: Postgres sometimes calls smgrcreate() to create
             // FSM, and smgrnblocks() on it immediately afterwards,
@@ -164,7 +158,7 @@ impl Timeline {
         }
 
         let key = rel_size_to_key(tag);
-        let mut buf = self.get(key, lsn).await?;
+        let mut buf = self.get(key, lsn, ctx).await?;
         let nblocks = buf.get_u32_le();
 
         if latest {
@@ -186,6 +180,7 @@ impl Timeline {
         tag: RelTag,
         lsn: Lsn,
         _latest: bool,
+        ctx: &TimelineRequestContext,
     ) -> Result<bool, PageReconstructError> {
         if tag.relnode == 0 {
             return Err(PageReconstructError::Other(anyhow::anyhow!(
@@ -199,7 +194,7 @@ impl Timeline {
         }
         // fetch directory listing
         let key = rel_dir_to_key(tag.spcnode, tag.dbnode);
-        let buf = self.get(key, lsn).await?;
+        let buf = self.get(key, lsn, ctx).await?;
 
         match RelDirectory::des(&buf).context("deserialization failure") {
             Ok(dir) => {
@@ -216,10 +211,11 @@ impl Timeline {
         spcnode: Oid,
         dbnode: Oid,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<HashSet<RelTag>, PageReconstructError> {
         // fetch directory listing
         let key = rel_dir_to_key(spcnode, dbnode);
-        let buf = self.get(key, lsn).await?;
+        let buf = self.get(key, lsn, ctx).await?;
 
         match RelDirectory::des(&buf).context("deserialization failure") {
             Ok(dir) => {
@@ -244,9 +240,10 @@ impl Timeline {
         segno: u32,
         blknum: BlockNumber,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<Bytes, PageReconstructError> {
         let key = slru_block_to_key(kind, segno, blknum);
-        self.get(key, lsn).await
+        self.get(key, lsn, ctx).await
     }
 
     /// Get size of an SLRU segment
@@ -255,9 +252,10 @@ impl Timeline {
         kind: SlruKind,
         segno: u32,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<BlockNumber, PageReconstructError> {
         let key = slru_segment_size_to_key(kind, segno);
-        let mut buf = self.get(key, lsn).await?;
+        let mut buf = self.get(key, lsn, ctx).await?;
         Ok(buf.get_u32_le())
     }
 
@@ -267,10 +265,11 @@ impl Timeline {
         kind: SlruKind,
         segno: u32,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<bool, PageReconstructError> {
         // fetch directory listing
         let key = slru_dir_to_key(kind);
-        let buf = self.get(key, lsn).await?;
+        let buf = self.get(key, lsn, ctx).await?;
 
         match SlruSegmentDirectory::des(&buf).context("deserialization failure") {
             Ok(dir) => {
@@ -291,6 +290,7 @@ impl Timeline {
     pub async fn find_lsn_for_timestamp(
         &self,
         search_timestamp: TimestampTz,
+        ctx: &TimelineRequestContext,
     ) -> Result<LsnForTimestamp, PageReconstructError> {
         let gc_cutoff_lsn_guard = self.get_latest_gc_cutoff_lsn();
         let min_lsn = *gc_cutoff_lsn_guard;
@@ -313,6 +313,7 @@ impl Timeline {
                     Lsn(mid * 8),
                     &mut found_smaller,
                     &mut found_larger,
+                    ctx,
                 )
                 .await?;
 
@@ -362,14 +363,18 @@ impl Timeline {
         probe_lsn: Lsn,
         found_smaller: &mut bool,
         found_larger: &mut bool,
+        ctx: &TimelineRequestContext,
     ) -> Result<bool, PageReconstructError> {
-        for segno in self.list_slru_segments(SlruKind::Clog, probe_lsn).await? {
+        for segno in self
+            .list_slru_segments(SlruKind::Clog, probe_lsn, ctx)
+            .await?
+        {
             let nblocks = self
-                .get_slru_segment_size(SlruKind::Clog, segno, probe_lsn)
+                .get_slru_segment_size(SlruKind::Clog, segno, probe_lsn, ctx)
                 .await?;
             for blknum in (0..nblocks).rev() {
                 let clog_page = self
-                    .get_slru_page_at_lsn(SlruKind::Clog, segno, blknum, probe_lsn)
+                    .get_slru_page_at_lsn(SlruKind::Clog, segno, blknum, probe_lsn, ctx)
                     .await?;
 
                 if clog_page.len() == BLCKSZ as usize + 8 {
@@ -394,11 +399,12 @@ impl Timeline {
         &self,
         kind: SlruKind,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<HashSet<u32>, PageReconstructError> {
         // fetch directory entry
         let key = slru_dir_to_key(kind);
 
-        let buf = self.get(key, lsn).await?;
+        let buf = self.get(key, lsn, ctx).await?;
         match SlruSegmentDirectory::des(&buf).context("deserialization failure") {
             Ok(dir) => Ok(dir.segments),
             Err(e) => Err(PageReconstructError::from(e)),
@@ -410,18 +416,21 @@ impl Timeline {
         spcnode: Oid,
         dbnode: Oid,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<Bytes, PageReconstructError> {
         let key = relmap_file_key(spcnode, dbnode);
 
-        self.get(key, lsn).await
+        let buf = self.get(key, lsn, ctx).await?;
+        Ok(buf)
     }
 
     pub async fn list_dbdirs(
         &self,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<HashMap<(Oid, Oid), bool>, PageReconstructError> {
         // fetch directory entry
-        let buf = self.get(DBDIR_KEY, lsn).await?;
+        let buf = self.get(DBDIR_KEY, lsn, ctx).await?;
 
         match DbDirectory::des(&buf).context("deserialization failure") {
             Ok(dir) => Ok(dir.dbdirs),
@@ -433,18 +442,20 @@ impl Timeline {
         &self,
         xid: TransactionId,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<Bytes, PageReconstructError> {
         let key = twophase_file_key(xid);
-        let buf = self.get(key, lsn).await?;
+        let buf = self.get(key, lsn, ctx).await?;
         Ok(buf)
     }
 
     pub async fn list_twophase_files(
         &self,
         lsn: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> Result<HashSet<TransactionId>, PageReconstructError> {
         // fetch directory entry
-        let buf = self.get(TWOPHASEDIR_KEY, lsn).await?;
+        let buf = self.get(TWOPHASEDIR_KEY, lsn, ctx).await?;
 
         match TwoPhaseDirectory::des(&buf).context("deserialization failure") {
             Ok(dir) => Ok(dir.xids),
@@ -452,12 +463,20 @@ impl Timeline {
         }
     }
 
-    pub async fn get_control_file(&self, lsn: Lsn) -> Result<Bytes, PageReconstructError> {
-        self.get(CONTROLFILE_KEY, lsn).await
+    pub async fn get_control_file(
+        &self,
+        lsn: Lsn,
+        ctx: &TimelineRequestContext,
+    ) -> Result<Bytes, PageReconstructError> {
+        self.get(CONTROLFILE_KEY, lsn, ctx).await
     }
 
-    pub async fn get_checkpoint(&self, lsn: Lsn) -> Result<Bytes, PageReconstructError> {
-        self.get(CHECKPOINT_KEY, lsn).await
+    pub async fn get_checkpoint(
+        &self,
+        lsn: Lsn,
+        ctx: &TimelineRequestContext,
+    ) -> Result<Bytes, PageReconstructError> {
+        self.get(CHECKPOINT_KEY, lsn, ctx).await
     }
 
     /// Does the same as get_current_logical_size but counted on demand.
@@ -468,27 +487,20 @@ impl Timeline {
     pub async fn get_current_logical_size_non_incremental(
         &self,
         lsn: Lsn,
-        cancel: CancellationToken,
-    ) -> Result<u64, CalculateLogicalSizeError> {
+        ctx: &TimelineRequestContext,
+    ) -> Result<u64, PageReconstructError> {
         // Fetch list of database dirs and iterate them
-        let buf = self.get(DBDIR_KEY, lsn).await.context("read dbdir")?;
+        let buf = self.get(DBDIR_KEY, lsn, ctx).await?;
         let dbdir = DbDirectory::des(&buf).context("deserialize db directory")?;
 
         let mut total_size: u64 = 0;
         for (spcnode, dbnode) in dbdir.dbdirs.keys() {
-            for rel in self
-                .list_rels(*spcnode, *dbnode, lsn)
-                .await
-                .context("list rels")?
-            {
-                if cancel.is_cancelled() {
-                    return Err(CalculateLogicalSizeError::Cancelled);
+            for rel in self.list_rels(*spcnode, *dbnode, lsn, ctx).await? {
+                if ctx.is_cancelled() {
+                    return Err(PageReconstructError::Cancelled);
                 }
                 let relsize_key = rel_size_to_key(rel);
-                let mut buf = self
-                    .get(relsize_key, lsn)
-                    .await
-                    .context("read relation size of {rel:?}")?;
+                let mut buf = self.get(relsize_key, lsn, ctx).await?;
                 let relsize = buf.get_u32_le();
 
                 total_size += relsize as u64;
@@ -501,7 +513,11 @@ impl Timeline {
     /// Get a KeySpace that covers all the Keys that are in use at the given LSN.
     /// Anything that's not listed maybe removed from the underlying storage (from
     /// that LSN forwards).
-    pub async fn collect_keyspace(&self, lsn: Lsn) -> anyhow::Result<KeySpace> {
+    pub async fn collect_keyspace(
+        &self,
+        lsn: Lsn,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<KeySpace> {
         // Iterate through key ranges, greedily packing them into partitions
         let mut result = KeySpaceAccum::new();
 
@@ -509,7 +525,7 @@ impl Timeline {
         result.add_key(DBDIR_KEY);
 
         // Fetch list of database dirs and iterate them
-        let buf = self.get(DBDIR_KEY, lsn).await?;
+        let buf = self.get(DBDIR_KEY, lsn, ctx).await?;
         let dbdir = DbDirectory::des(&buf).context("deserialization failure")?;
 
         let mut dbs: Vec<(Oid, Oid)> = dbdir.dbdirs.keys().cloned().collect();
@@ -519,14 +535,15 @@ impl Timeline {
             result.add_key(rel_dir_to_key(spcnode, dbnode));
 
             let mut rels: Vec<RelTag> = self
-                .list_rels(spcnode, dbnode, lsn)
+                .list_rels(spcnode, dbnode, lsn, ctx)
                 .await?
-                .into_iter()
+                .iter()
+                .cloned()
                 .collect();
             rels.sort_unstable();
             for rel in rels {
                 let relsize_key = rel_size_to_key(rel);
-                let mut buf = self.get(relsize_key, lsn).await?;
+                let mut buf = self.get(relsize_key, lsn, ctx).await?;
                 let relsize = buf.get_u32_le();
 
                 result.add_range(rel_block_to_key(rel, 0)..rel_block_to_key(rel, relsize));
@@ -542,13 +559,13 @@ impl Timeline {
         ] {
             let slrudir_key = slru_dir_to_key(kind);
             result.add_key(slrudir_key);
-            let buf = self.get(slrudir_key, lsn).await?;
+            let buf = self.get(slrudir_key, lsn, ctx).await?;
             let dir = SlruSegmentDirectory::des(&buf).context("deserialization failure")?;
             let mut segments: Vec<u32> = dir.segments.iter().cloned().collect();
             segments.sort_unstable();
             for segno in segments {
                 let segsize_key = slru_segment_size_to_key(kind, segno);
-                let mut buf = self.get(segsize_key, lsn).await?;
+                let mut buf = self.get(segsize_key, lsn, ctx).await?;
                 let segsize = buf.get_u32_le();
 
                 result.add_range(
@@ -560,7 +577,7 @@ impl Timeline {
 
         // Then pg_twophase
         result.add_key(TWOPHASEDIR_KEY);
-        let buf = self.get(TWOPHASEDIR_KEY, lsn).await?;
+        let buf = self.get(TWOPHASEDIR_KEY, lsn, ctx).await?;
         let twophase_dir = TwoPhaseDirectory::des(&buf).context("deserialization failure")?;
         let mut xids: Vec<TransactionId> = twophase_dir.xids.iter().cloned().collect();
         xids.sort_unstable();
@@ -723,9 +740,10 @@ impl<'a> DatadirModification<'a> {
         spcnode: Oid,
         dbnode: Oid,
         img: Bytes,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         // Add it to the directory (if it doesn't exist already)
-        let buf = self.get(DBDIR_KEY).await?;
+        let buf = self.get(DBDIR_KEY, ctx).await?;
         let mut dbdir = DbDirectory::des(&buf)?;
 
         let r = dbdir.dbdirs.insert((spcnode, dbnode), true);
@@ -755,9 +773,10 @@ impl<'a> DatadirModification<'a> {
         &mut self,
         xid: TransactionId,
         img: Bytes,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         // Add it to the directory entry
-        let buf = self.get(TWOPHASEDIR_KEY).await?;
+        let buf = self.get(TWOPHASEDIR_KEY, ctx).await?;
         let mut dir = TwoPhaseDirectory::des(&buf)?;
         if !dir.xids.insert(xid) {
             anyhow::bail!("twophase file for xid {} already exists", xid);
@@ -781,16 +800,21 @@ impl<'a> DatadirModification<'a> {
         Ok(())
     }
 
-    pub async fn drop_dbdir(&mut self, spcnode: Oid, dbnode: Oid) -> anyhow::Result<()> {
+    pub async fn drop_dbdir(
+        &mut self,
+        spcnode: Oid,
+        dbnode: Oid,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         let req_lsn = self.tline.get_last_record_lsn();
 
         let total_blocks = self
             .tline
-            .get_db_size(spcnode, dbnode, req_lsn, true)
+            .get_db_size(spcnode, dbnode, req_lsn, true, ctx)
             .await?;
 
         // Remove entry from dbdir
-        let buf = self.get(DBDIR_KEY).await?;
+        let buf = self.get(DBDIR_KEY, ctx).await?;
         let mut dir = DbDirectory::des(&buf)?;
         if dir.dbdirs.remove(&(spcnode, dbnode)).is_some() {
             let buf = DbDirectory::ser(&dir)?;
@@ -817,11 +841,12 @@ impl<'a> DatadirModification<'a> {
         &mut self,
         rel: RelTag,
         nblocks: BlockNumber,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         anyhow::ensure!(rel.relnode != 0, "invalid relnode");
         // It's possible that this is the first rel for this db in this
         // tablespace.  Create the reldir entry for it if so.
-        let mut dbdir = DbDirectory::des(&self.get(DBDIR_KEY).await?)?;
+        let mut dbdir = DbDirectory::des(&self.get(DBDIR_KEY, ctx).await?)?;
         let rel_dir_key = rel_dir_to_key(rel.spcnode, rel.dbnode);
         let mut rel_dir = if dbdir.dbdirs.get(&(rel.spcnode, rel.dbnode)).is_none() {
             // Didn't exist. Update dbdir
@@ -833,7 +858,7 @@ impl<'a> DatadirModification<'a> {
             RelDirectory::default()
         } else {
             // reldir already exists, fetch it
-            RelDirectory::des(&self.get(rel_dir_key).await?)?
+            RelDirectory::des(&self.get(rel_dir_key, ctx).await?)?
         };
 
         // Add the new relation to the rel directory entry, and write it back
@@ -865,13 +890,14 @@ impl<'a> DatadirModification<'a> {
         &mut self,
         rel: RelTag,
         nblocks: BlockNumber,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         anyhow::ensure!(rel.relnode != 0, "invalid relnode");
         let last_lsn = self.tline.get_last_record_lsn();
-        if self.tline.get_rel_exists(rel, last_lsn, true).await? {
+        if self.tline.get_rel_exists(rel, last_lsn, true, ctx).await? {
             let size_key = rel_size_to_key(rel);
             // Fetch the old size first
-            let old_size = self.get(size_key).await?.get_u32_le();
+            let old_size = self.get(size_key, ctx).await?.get_u32_le();
 
             // Update the entry with the new size.
             let buf = nblocks.to_le_bytes();
@@ -895,12 +921,13 @@ impl<'a> DatadirModification<'a> {
         &mut self,
         rel: RelTag,
         nblocks: BlockNumber,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         anyhow::ensure!(rel.relnode != 0, "invalid relnode");
 
         // Put size
         let size_key = rel_size_to_key(rel);
-        let old_size = self.get(size_key).await?.get_u32_le();
+        let old_size = self.get(size_key, ctx).await?.get_u32_le();
 
         // only extend relation here. never decrease the size
         if nblocks > old_size {
@@ -916,12 +943,16 @@ impl<'a> DatadirModification<'a> {
     }
 
     /// Drop a relation.
-    pub async fn put_rel_drop(&mut self, rel: RelTag) -> anyhow::Result<()> {
+    pub async fn put_rel_drop(
+        &mut self,
+        rel: RelTag,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         anyhow::ensure!(rel.relnode != 0, "invalid relnode");
 
         // Remove it from the directory entry
         let dir_key = rel_dir_to_key(rel.spcnode, rel.dbnode);
-        let buf = self.get(dir_key).await?;
+        let buf = self.get(dir_key, ctx).await?;
         let mut dir = RelDirectory::des(&buf)?;
 
         if dir.rels.remove(&(rel.relnode, rel.forknum)) {
@@ -932,7 +963,7 @@ impl<'a> DatadirModification<'a> {
 
         // update logical size
         let size_key = rel_size_to_key(rel);
-        let old_size = self.get(size_key).await?.get_u32_le();
+        let old_size = self.get(size_key, ctx).await?.get_u32_le();
         self.pending_nblocks -= old_size as i64;
 
         // Remove enty from relation size cache
@@ -949,10 +980,11 @@ impl<'a> DatadirModification<'a> {
         kind: SlruKind,
         segno: u32,
         nblocks: BlockNumber,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         // Add it to the directory entry
         let dir_key = slru_dir_to_key(kind);
-        let buf = self.get(dir_key).await?;
+        let buf = self.get(dir_key, ctx).await?;
         let mut dir = SlruSegmentDirectory::des(&buf)?;
 
         if !dir.segments.insert(segno) {
@@ -988,10 +1020,15 @@ impl<'a> DatadirModification<'a> {
     }
 
     /// This method is used for marking truncated SLRU files
-    pub async fn drop_slru_segment(&mut self, kind: SlruKind, segno: u32) -> anyhow::Result<()> {
+    pub async fn drop_slru_segment(
+        &mut self,
+        kind: SlruKind,
+        segno: u32,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         // Remove it from the directory entry
         let dir_key = slru_dir_to_key(kind);
-        let buf = self.get(dir_key).await?;
+        let buf = self.get(dir_key, ctx).await?;
         let mut dir = SlruSegmentDirectory::des(&buf)?;
 
         if !dir.segments.remove(&segno) {
@@ -1015,9 +1052,13 @@ impl<'a> DatadirModification<'a> {
     }
 
     /// This method is used for marking truncated SLRU files
-    pub async fn drop_twophase_file(&mut self, xid: TransactionId) -> anyhow::Result<()> {
+    pub async fn drop_twophase_file(
+        &mut self,
+        xid: TransactionId,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         // Remove it from the directory entry
-        let buf = self.get(TWOPHASEDIR_KEY).await?;
+        let buf = self.get(TWOPHASEDIR_KEY, ctx).await?;
         let mut dir = TwoPhaseDirectory::des(&buf)?;
 
         if !dir.xids.remove(&xid) {
@@ -1111,7 +1152,11 @@ impl<'a> DatadirModification<'a> {
 
     // Internal helper functions to batch the modifications
 
-    async fn get(&self, key: Key) -> Result<Bytes, PageReconstructError> {
+    async fn get(
+        &self,
+        key: Key,
+        ctx: &TimelineRequestContext,
+    ) -> Result<Bytes, PageReconstructError> {
         // Have we already updated the same key? Read the pending updated
         // version in that case.
         //
@@ -1132,7 +1177,7 @@ impl<'a> DatadirModification<'a> {
             }
         } else {
             let lsn = Lsn::max(self.tline.get_last_record_lsn(), self.lsn);
-            self.tline.get(key, lsn).await
+            self.tline.get(key, lsn, ctx).await
         }
     }
 
@@ -1539,17 +1584,18 @@ fn is_slru_block_key(key: Key) -> bool {
 
 #[cfg(test)]
 pub fn create_test_timeline(
-    tenant: &crate::tenant::Tenant,
+    tenant: &std::sync::Arc<crate::tenant::Tenant>,
     timeline_id: utils::id::TimelineId,
     pg_version: u32,
-) -> anyhow::Result<std::sync::Arc<Timeline>> {
-    let tline = tenant
-        .create_empty_timeline(timeline_id, Lsn(8), pg_version)?
-        .initialize()?;
+    tenant_ctx: &crate::tenant::TenantRequestContext,
+) -> anyhow::Result<(std::sync::Arc<Timeline>, TimelineRequestContext)> {
+    let (tline, timeline_ctx) =
+        tenant.create_empty_timeline(timeline_id, Lsn(8), pg_version, tenant_ctx)?;
+    let tline = tline.initialize(&timeline_ctx)?;
     let mut m = tline.begin_modification(Lsn(8));
     m.init_empty()?;
     m.commit()?;
-    Ok(tline)
+    Ok((tline, timeline_ctx))
 }
 
 #[allow(clippy::bool_assert_comparison)]

pageserver/src/task_mgr.rs

@@ -1,59 +1,21 @@
 //!
-//! This module provides centralized handling of tokio tasks in the Page Server.
+//! This module provides some helpers for spawning tokio tasks in the pageserver.
 //!
-//! We provide a few basic facilities:
-//! - A global registry of tasks that lists what kind of tasks they are, and
-//!   which tenant or timeline they are working on
-//!
-//! - The ability to request a task to shut down.
-//!
-//!
-//! # How it works?
-//!
-//! There is a global hashmap of all the tasks (`TASKS`). Whenever a new
-//! task is spawned, a PageServerTask entry is added there, and when a
-//! task dies, it removes itself from the hashmap. If you want to kill a
-//! task, you can scan the hashmap to find it.
-//!
-//! # Task shutdown
-//!
-//! To kill a task, we rely on co-operation from the victim. Each task is
-//! expected to periodically call the `is_shutdown_requested()` function, and
-//! if it returns true, exit gracefully. In addition to that, when waiting for
-//! the network or other long-running operation, you can use
-//! `shutdown_watcher()` function to get a Future that will become ready if
-//! the current task has been requested to shut down. You can use that with
-//! Tokio select!().
-//!
-//! TODO: This would be a good place to also handle panics in a somewhat sane way.
-//! Depending on what task panics, we might want to kill the whole server, or
-//! only a single tenant or timeline.
+//! Mostly just a wrapper around tokio::spawn, with some code to handle panics.
 //!
 
-// Clippy 1.60 incorrectly complains about the tokio::task_local!() macro.
-// Silence it. See https://github.com/rust-lang/rust-clippy/issues/9224.
-#![allow(clippy::declare_interior_mutable_const)]
-
-use std::collections::HashMap;
-use std::fmt;
 use std::future::Future;
-use std::panic::AssertUnwindSafe;
-use std::sync::atomic::{AtomicU64, Ordering};
-use std::sync::{Arc, Mutex};
+use std::panic::{resume_unwind, AssertUnwindSafe};
 
 use futures::FutureExt;
 use tokio::runtime::Runtime;
 use tokio::task::JoinHandle;
-use tokio::task_local;
-use tokio_util::sync::CancellationToken;
 
-use tracing::{debug, error, info, warn};
+use tracing::{debug, error, info};
 
 use once_cell::sync::Lazy;
 
-use utils::id::{TenantId, TimelineId};
-
-use crate::shutdown_pageserver;
+use crate::context::{self, TaskKind};
 
 //
 // There are four runtimes:
@@ -92,10 +54,6 @@ use crate::shutdown_pageserver;
 // runtime. If a GetPage request comes in before the load of a tenant has finished, the
 // GetPage request will wait for the tenant load to finish.
 //
-// The core Timeline code is synchronous, and uses a bunch of std Mutexes and RWLocks to
-// protect data structures. Let's keep it that way. Synchronous code is easier to debug
-// and analyze, and there's a lot of hairy, low-level, performance critical code there.
-//
 // It's nice to have different runtimes, so that you can quickly eyeball how much CPU
 // time each class of operations is taking, with 'top -H' or similar.
 //
@@ -135,355 +93,81 @@ pub static BACKGROUND_RUNTIME: Lazy<Runtime> = Lazy::new(|| {
         .expect("Failed to create background op runtime")
 });
 
-#[derive(Debug, Clone, Copy)]
-pub struct PageserverTaskId(u64);
-
-impl fmt::Display for PageserverTaskId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        self.0.fmt(f)
-    }
-}
-
-/// Each task that we track is associated with a "task ID". It's just an
-/// increasing number that we assign. Note that it is different from tokio::task::Id.
-static NEXT_TASK_ID: AtomicU64 = AtomicU64::new(1);
-
-/// Global registry of tasks
-static TASKS: Lazy<Mutex<HashMap<u64, Arc<PageServerTask>>>> =
-    Lazy::new(|| Mutex::new(HashMap::new()));
-
-task_local! {
-    // This is a cancellation token which will be cancelled when a task needs to shut down. The
-    // root token is kept in the global registry, so that anyone can send the signal to request
-    // task shutdown.
-    static SHUTDOWN_TOKEN: CancellationToken;
-
-    // Each task holds reference to its own PageServerTask here.
-    static CURRENT_TASK: Arc<PageServerTask>;
-}
-
-///
-/// There are many kinds of tasks in the system. Some are associated with a particular
-/// tenant or timeline, while others are global.
-///
-/// Note that we don't try to limit how many task of a certain kind can be running
-/// at the same time.
-///
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub enum TaskKind {
-    // libpq listener task. It just accepts connection and spawns a
-    // PageRequestHandler task for each connection.
-    LibpqEndpointListener,
-
-    // HTTP endpoint listener.
-    HttpEndpointListener,
-
-    // Task that handles a single connection. A PageRequestHandler task
-    // starts detached from any particular tenant or timeline, but it can be
-    // associated with one later, after receiving a command from the client.
-    PageRequestHandler,
-
-    // Manages the WAL receiver connection for one timeline. It subscribes to
-    // events from storage_broker, decides which safekeeper to connect to. It spawns a
-    // separate WalReceiverConnection task to handle each connection.
-    WalReceiverManager,
-
-    // Handles a connection to a safekeeper, to stream WAL to a timeline.
-    WalReceiverConnection,
-
-    // Garbage collection worker. One per tenant
-    GarbageCollector,
-
-    // Compaction. One per tenant.
-    Compaction,
-
-    // Initial logical size calculation
-    InitialLogicalSizeCalculation,
-
-    // Task that flushes frozen in-memory layers to disk
-    LayerFlushTask,
-
-    // Task that uploads a file to remote storage
-    RemoteUploadTask,
-
-    // Task that downloads a file from remote storage
-    RemoteDownloadTask,
-
-    // task that handles the initial downloading of all tenants
-    InitialLoad,
-
-    // task that handles attaching a tenant
-    Attach,
-
-    // task that handhes metrics collection
-    MetricsCollection,
-
-    // task that drives downloading layers
-    DownloadAllRemoteLayers,
-}
-
-#[derive(Default)]
-struct MutableTaskState {
-    /// Tenant and timeline that this task is associated with.
-    tenant_id: Option<TenantId>,
-    timeline_id: Option<TimelineId>,
-
-    /// Handle for waiting for the task to exit. It can be None, if the
-    /// the task has already exited.
-    join_handle: Option<JoinHandle<()>>,
-}
-
-struct PageServerTask {
-    #[allow(dead_code)] // unused currently
-    task_id: PageserverTaskId,
-
-    kind: TaskKind,
-
-    name: String,
-
-    // To request task shutdown, just cancel this token.
-    cancel: CancellationToken,
-
-    mutable: Mutex<MutableTaskState>,
-}
-
 /// 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
+///
+/// This is a wrapper around tokio::spawn. One difference is that the Future
+/// is marked to return nothing to avoid silently swallowing errors. This
+/// forces the future to handle errors by itself. If you need the return
+/// value, you could create another function that passes it through, but we
+/// don't have a need for that currently.
+///
+/// If shutdown_process_on_panic is set to true, panic of the task will lead
+/// to shutdown of entire process. Otherwise we log the panic and continue.
 pub fn spawn<F>(
     runtime: &tokio::runtime::Handle,
-    kind: TaskKind,
-    tenant_id: Option<TenantId>,
-    timeline_id: Option<TimelineId>,
     name: &str,
-    shutdown_process_on_error: bool,
+    shutdown_process_on_panic: bool,
     future: F,
-) -> PageserverTaskId
+) -> JoinHandle<F::Output>
 where
-    F: Future<Output = anyhow::Result<()>> + Send + 'static,
+    F: Future<Output = ()> + Send + 'static,
 {
-    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),
-        kind,
-        name: name.to_string(),
-        cancel: cancel.clone(),
-        mutable: Mutex::new(MutableTaskState {
-            tenant_id,
-            timeline_id,
-            join_handle: None,
-        }),
-    });
-
-    TASKS.lock().unwrap().insert(task_id, Arc::clone(&task));
-
-    let mut task_mut = task.mutable.lock().unwrap();
-
     let task_name = name.to_string();
-    let task_cloned = Arc::clone(&task);
-    let join_handle = runtime.spawn(task_wrapper(
-        task_name,
-        task_id,
-        task_cloned,
-        cancel,
-        shutdown_process_on_error,
-        future,
-    ));
-    task_mut.join_handle = Some(join_handle);
-    drop(task_mut);
-
-    // The task is now running. Nothing more to do here
-    PageserverTaskId(task_id)
+    runtime.spawn(task_wrapper(task_name, shutdown_process_on_panic, future))
 }
 
-/// This wrapper function runs in a newly-spawned task. It initializes the
-/// task-local variables and calls the payload function.
-async fn task_wrapper<F>(
-    task_name: String,
-    task_id: u64,
-    task: Arc<PageServerTask>,
-    shutdown_token: CancellationToken,
-    shutdown_process_on_error: bool,
-    future: F,
-) where
-    F: Future<Output = anyhow::Result<()>> + Send + 'static,
+/// This wrapper function runs in a newly-spawned task. To handle panics.
+async fn task_wrapper<F, R>(task_name: String, shutdown_process_on_panic: bool, future: F) -> R
+where
+    F: Future<Output = R> + Send + 'static,
 {
     debug!("Starting task '{}'", task_name);
 
-    let result = SHUTDOWN_TOKEN
-        .scope(
-            shutdown_token,
-            CURRENT_TASK.scope(task, {
-                // We use AssertUnwindSafe here so that the payload function
-                // doesn't need to be UnwindSafe. We don't do anything after the
-                // unwinding that would expose us to unwind-unsafe behavior.
-                AssertUnwindSafe(future).catch_unwind()
-            }),
-        )
-        .await;
-    task_finish(result, task_name, task_id, shutdown_process_on_error).await;
-}
+    // We use AssertUnwindSafe here so that the payload function
+    // doesn't need to be UnwindSafe. We don't do anything after the
+    // unwinding that would expose us to unwind-unsafe behavior.
+    let result = AssertUnwindSafe(future).catch_unwind().await;
 
-async fn task_finish(
-    result: std::result::Result<
-        anyhow::Result<()>,
-        std::boxed::Box<dyn std::any::Any + std::marker::Send>,
-    >,
-    task_name: String,
-    task_id: u64,
-    shutdown_process_on_error: bool,
-) {
-    // Remove our entry from the global hashmap.
-    let task = TASKS
-        .lock()
-        .unwrap()
-        .remove(&task_id)
-        .expect("no task in registry");
-
-    let mut shutdown_process = false;
-    {
-        let task_mut = task.mutable.lock().unwrap();
-
-        match result {
-            Ok(Ok(())) => {
-                debug!("Task '{}' exited normally", task_name);
-            }
-            Ok(Err(err)) => {
-                if shutdown_process_on_error {
-                    error!(
-                        "Shutting down: task '{}' tenant_id: {:?}, timeline_id: {:?} exited with error: {:?}",
-                        task_name, task_mut.tenant_id, task_mut.timeline_id, err
-                    );
-                    shutdown_process = true;
-                } else {
-                    error!(
-                        "Task '{}' tenant_id: {:?}, timeline_id: {:?} exited with error: {:?}",
-                        task_name, task_mut.tenant_id, task_mut.timeline_id, err
-                    );
-                }
-            }
-            Err(err) => {
-                if shutdown_process_on_error {
-                    error!(
-                        "Shutting down: task '{}' tenant_id: {:?}, timeline_id: {:?} panicked: {:?}",
-                        task_name, task_mut.tenant_id, task_mut.timeline_id, err
-                    );
-                    shutdown_process = true;
-                } else {
-                    error!(
-                        "Task '{}' tenant_id: {:?}, timeline_id: {:?} panicked: {:?}",
-                        task_name, task_mut.tenant_id, task_mut.timeline_id, err
-                    );
-                }
+    // Handle panics
+    match result {
+        Ok(result) => {
+            debug!("Task '{}' exited normally", task_name);
+            result
+        }
+        Err(err) => {
+            if shutdown_process_on_panic {
+                error!("Shutting down: task '{}' panicked: {:?}", task_name, err);
+                shutdown_pageserver(1).await;
+                unreachable!();
+            } else {
+                error!("Task '{}'  panicked: {:?}", task_name, err);
+                resume_unwind(err);
             }
         }
     }
-
-    if shutdown_process {
-        shutdown_pageserver(1).await;
-    }
 }
 
-// expected to be called from the task of the given id.
-pub fn associate_with(tenant_id: Option<TenantId>, timeline_id: Option<TimelineId>) {
-    CURRENT_TASK.with(|ct| {
-        let mut task_mut = ct.mutable.lock().unwrap();
-        task_mut.tenant_id = tenant_id;
-        task_mut.timeline_id = timeline_id;
-    });
-}
-
-/// Is there a task running that matches the criteria
-
-/// Signal and wait for tasks to shut down.
 ///
+/// Perform pageserver shutdown. This is called on receiving a signal,
+/// or if one of the tasks marked as 'shutdown_process_on_error' dies.
 ///
-/// The arguments are used to select the tasks to kill. Any None arguments are
-/// ignored. For example, to shut down all WalReceiver tasks:
-///
-///   shutdown_tasks(Some(TaskKind::WalReceiver), None, None)
-///
-/// Or to shut down all tasks for given timeline:
-///
-///   shutdown_tasks(None, Some(tenant_id), Some(timeline_id))
-///
-pub async fn shutdown_tasks(
-    kind: Option<TaskKind>,
-    tenant_id: Option<TenantId>,
-    timeline_id: Option<TimelineId>,
-) {
-    let mut victim_tasks = Vec::new();
+/// This never returns.
+pub async fn shutdown_pageserver(exit_code: i32) {
+    // Shut down the libpq endpoint task. This prevents new connections from
+    // being accepted.
+    context::shutdown_tasks(TaskKind::LibpqEndpointListener).await;
 
-    {
-        let tasks = TASKS.lock().unwrap();
-        for task in tasks.values() {
-            let task_mut = task.mutable.lock().unwrap();
-            if (kind.is_none() || Some(task.kind) == kind)
-                && (tenant_id.is_none() || task_mut.tenant_id == tenant_id)
-                && (timeline_id.is_none() || task_mut.timeline_id == timeline_id)
-            {
-                task.cancel.cancel();
-                victim_tasks.push(Arc::clone(task));
-            }
-        }
-    }
+    // Shut down all tenants gracefully
+    crate::tenant::mgr::shutdown_all_tenants().await;
 
-    for task in victim_tasks {
-        let join_handle = {
-            let mut task_mut = task.mutable.lock().unwrap();
-            info!("waiting for {} to shut down", task.name);
-            let join_handle = task_mut.join_handle.take();
-            drop(task_mut);
-            join_handle
-        };
-        if let Some(join_handle) = join_handle {
-            let _ = join_handle.await;
-        } else {
-            // Possibly one of:
-            //  * The task had not even fully started yet.
-            //  * It was shut down concurrently and already exited
-        }
-    }
-}
-
-pub fn current_task_kind() -> Option<TaskKind> {
-    CURRENT_TASK.try_with(|ct| ct.kind).ok()
-}
-
-pub fn current_task_id() -> Option<PageserverTaskId> {
-    CURRENT_TASK.try_with(|ct| ct.task_id).ok()
-}
-
-/// A Future that can be used to check if the current task has been requested to
-/// shut down.
-pub async fn shutdown_watcher() {
-    let token = SHUTDOWN_TOKEN
-        .try_with(|t| t.clone())
-        .expect("shutdown_requested() called in an unexpected task or thread");
-
-    token.cancelled().await;
-}
-
-/// Clone the current task's cancellation token, which can be moved across tasks.
-///
-/// When the task which is currently executing is shutdown, the cancellation token will be
-/// cancelled. It can however be moved to other tasks, such as `tokio::task::spawn_blocking` or
-/// `tokio::task::JoinSet::spawn`.
-pub fn shutdown_token() -> CancellationToken {
-    SHUTDOWN_TOKEN
-        .try_with(|t| t.clone())
-        .expect("shutdown_token() called in an unexpected task or thread")
-}
-
-/// Has the current task been requested to shut down?
-pub fn is_shutdown_requested() -> bool {
-    if let Ok(cancel) = SHUTDOWN_TOKEN.try_with(|t| t.clone()) {
-        cancel.is_cancelled()
-    } else {
-        if !cfg!(test) {
-            warn!("is_shutdown_requested() called in an unexpected task or thread");
-        }
-        false
-    }
+    // Shut down the HTTP endpoint last, so that you can still check the server's
+    // status while it's shutting down.
+    // FIXME: We should probably stop accepting commands like attach/detach earlier.
+    context::shutdown_tasks(TaskKind::HttpEndpointListener).await;
+
+    // There should be nothing left, but let's be sure
+    context::shutdown_all_tasks().await;
+
+    info!("Shut down successfully completed");
+    std::process::exit(exit_code);
 }

pageserver/src/tenant/mgr.rs

@@ -8,6 +8,8 @@ use std::sync::Arc;
 use tokio::fs;
 
 use anyhow::Context;
+use futures::stream::FuturesUnordered;
+use futures::StreamExt;
 use once_cell::sync::Lazy;
 use tokio::sync::RwLock;
 use tracing::*;
@@ -16,9 +18,9 @@ use remote_storage::GenericRemoteStorage;
 use utils::crashsafe;
 
 use crate::config::PageServerConf;
-use crate::task_mgr::{self, TaskKind};
+use crate::context::RequestContext;
 use crate::tenant::config::TenantConfOpt;
-use crate::tenant::{Tenant, TenantState};
+use crate::tenant::{Tenant, TenantRequestContext, TenantState};
 use crate::IGNORED_TENANT_FILE_NAME;
 
 use utils::fs_ext::PathExt;
@@ -181,25 +183,11 @@ pub async fn shutdown_all_tenants() {
         tenants_to_shut_down
     };
 
-    // Shut down all existing walreceiver connections and stop accepting the new ones.
-    task_mgr::shutdown_tasks(Some(TaskKind::WalReceiverManager), None, None).await;
-
-    // Ok, no background tasks running anymore. Flush any remaining data in
-    // memory to disk.
-    //
-    // We assume that any incoming connections that might request pages from
-    // the tenant have already been terminated by the caller, so there
-    // should be no more activity in any of the repositories.
-    //
-    // On error, log it but continue with the shutdown for other tenants.
-    for tenant in tenants_to_shut_down {
-        let tenant_id = tenant.tenant_id();
-        debug!("shutdown tenant {tenant_id}");
-
-        if let Err(err) = tenant.freeze_and_flush().await {
-            error!("Could not checkpoint tenant {tenant_id} during shutdown: {err:?}");
-        }
+    let mut shutdown_futures: FuturesUnordered<_> = FuturesUnordered::new();
+    for tenant in tenants_to_shut_down.iter() {
+        shutdown_futures.push(tenant.graceful_shutdown(true));
     }
+    while let Some(_result) = shutdown_futures.next().await {}
 }
 
 pub async fn create_tenant(
@@ -234,36 +222,47 @@ pub async fn update_tenant_config(
     conf: &'static PageServerConf,
     tenant_conf: TenantConfOpt,
     tenant_id: TenantId,
+    ctx: &RequestContext,
 ) -> anyhow::Result<()> {
     info!("configuring tenant {tenant_id}");
-    get_tenant(tenant_id, true)
-        .await?
-        .update_tenant_config(tenant_conf);
+    let (tenant, _ctx) = get_active_tenant(tenant_id, ctx).await?;
+
+    tenant.update_tenant_config(tenant_conf);
     Tenant::persist_tenant_config(&conf.tenant_config_path(tenant_id), tenant_conf, false)?;
     Ok(())
 }
 
 /// Gets the tenant from the in-memory data, erroring if it's absent 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 async fn get_tenant(tenant_id: TenantId, active_only: bool) -> anyhow::Result<Arc<Tenant>> {
+pub async fn get_active_tenant(
+    tenant_id: TenantId,
+    parent_ctx: &RequestContext,
+) -> anyhow::Result<(Arc<Tenant>, TenantRequestContext)> {
+    let tenant = get_tenant(tenant_id).await?;
+    let tenant_ctx = match tenant.get_context(parent_ctx) {
+        Ok(ctx) => ctx,
+        Err(state) => anyhow::bail!("Tenant {} is not active, state: {:?}", tenant_id, state,),
+    };
+    Ok((tenant, tenant_ctx))
+}
+
+pub async fn get_tenant(tenant_id: TenantId) -> anyhow::Result<Arc<Tenant>> {
     let m = TENANTS.read().await;
     let tenant = m
         .get(&tenant_id)
         .with_context(|| format!("Tenant {tenant_id} not found in the local state"))?;
-    if active_only && !tenant.is_active() {
-        anyhow::bail!(
-            "Tenant {tenant_id} is not active. Current state: {:?}",
-            tenant.current_state()
-        )
-    } else {
-        Ok(Arc::clone(tenant))
-    }
+
+    Ok(Arc::clone(tenant))
 }
 
-pub async fn delete_timeline(tenant_id: TenantId, timeline_id: TimelineId) -> anyhow::Result<()> {
-    match get_tenant(tenant_id, true).await {
-        Ok(tenant) => {
-            tenant.delete_timeline(timeline_id).await?;
+pub async fn delete_timeline(
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+    ctx: &RequestContext,
+) -> anyhow::Result<()> {
+    match get_active_tenant(tenant_id, ctx).await {
+        Ok((tenant, ctx)) => {
+            tenant.delete_timeline(timeline_id, &ctx).await?;
         }
         Err(e) => anyhow::bail!("Cannot access tenant {tenant_id} in local tenant state: {e:?}"),
     }
@@ -395,27 +394,31 @@ where
     // The exclusive lock here ensures we don't miss the tenant state updates before trying another removal.
     // tenant-wde cleanup operations may take some time (removing the entire tenant directory), we want to
     // avoid holding the lock for the entire process.
-    {
+    let tenant = {
         let tenants_accessor = TENANTS.write().await;
         match tenants_accessor.get(&tenant_id) {
             Some(tenant) => match tenant.current_state() {
                 TenantState::Attaching
                 | TenantState::Loading
                 | TenantState::Broken
-                | TenantState::Active => tenant.set_stopping(),
+                | TenantState::Active => {
+                    tenant.set_stopping();
+                    Arc::clone(tenant)
+                }
                 TenantState::Stopping => {
                     anyhow::bail!("Tenant {tenant_id} is stopping already")
                 }
             },
             None => anyhow::bail!("Tenant not found for id {tenant_id}"),
         }
-    }
+    };
 
-    // shutdown all tenant and timeline tasks: gc, compaction, page service)
-    // No new tasks will be started for this tenant because it's in `Stopping` state.
-    // Hence, once we're done here, the `tenant_cleanup` callback can mutate tenant on-disk state freely.
-    task_mgr::shutdown_tasks(None, Some(tenant_id), None).await;
+    // Shut down all tenant and timeline tasks.
+    tenant.graceful_shutdown(true).await;
 
+    // All tasks that operated on the tenant or any of its timelines have no finished,
+    // and they are in Stopped state so that new ones cannot appear anymore. Proceed
+    // with the cleanup.
     match tenant_cleanup
         .await
         .with_context(|| format!("Failed to run cleanup for tenant {tenant_id}"))
@@ -437,108 +440,3 @@ where
         }
     }
 }
-
-#[cfg(feature = "testing")]
-use {
-    crate::repository::GcResult, pageserver_api::models::TimelineGcRequest,
-    utils::http::error::ApiError,
-};
-
-#[cfg(feature = "testing")]
-pub async fn immediate_gc(
-    tenant_id: TenantId,
-    timeline_id: TimelineId,
-    gc_req: TimelineGcRequest,
-) -> Result<tokio::sync::oneshot::Receiver<Result<GcResult, anyhow::Error>>, ApiError> {
-    let guard = TENANTS.read().await;
-
-    let tenant = guard
-        .get(&tenant_id)
-        .map(Arc::clone)
-        .with_context(|| format!("Tenant {tenant_id} not found"))
-        .map_err(ApiError::NotFound)?;
-
-    let gc_horizon = gc_req.gc_horizon.unwrap_or_else(|| tenant.get_gc_horizon());
-    // Use tenant's pitr setting
-    let pitr = tenant.get_pitr_interval();
-
-    // Run in task_mgr to avoid race with detach operation
-    let (task_done, wait_task_done) = tokio::sync::oneshot::channel();
-    task_mgr::spawn(
-        &tokio::runtime::Handle::current(),
-        TaskKind::GarbageCollector,
-        Some(tenant_id),
-        Some(timeline_id),
-        &format!("timeline_gc_handler garbage collection run for tenant {tenant_id} timeline {timeline_id}"),
-        false,
-        async move {
-            fail::fail_point!("immediate_gc_task_pre");
-            let result = tenant
-                .gc_iteration(Some(timeline_id), gc_horizon, pitr)
-                .instrument(info_span!("manual_gc", tenant = %tenant_id, timeline = %timeline_id))
-                .await;
-                // FIXME: `gc_iteration` can return an error for multiple reasons; we should handle it
-                // better once the types support it.
-            match task_done.send(result) {
-                Ok(_) => (),
-                Err(result) => error!("failed to send gc result: {result:?}"),
-            }
-            Ok(())
-        }
-    );
-
-    // drop the guard until after we've spawned the task so that timeline shutdown will wait for the task
-    drop(guard);
-
-    Ok(wait_task_done)
-}
-
-#[cfg(feature = "testing")]
-pub async fn immediate_compact(
-    tenant_id: TenantId,
-    timeline_id: TimelineId,
-) -> Result<tokio::sync::oneshot::Receiver<anyhow::Result<()>>, ApiError> {
-    let guard = TENANTS.read().await;
-
-    let tenant = guard
-        .get(&tenant_id)
-        .map(Arc::clone)
-        .with_context(|| format!("Tenant {tenant_id} not found"))
-        .map_err(ApiError::NotFound)?;
-
-    let timeline = tenant
-        .get_timeline(timeline_id, true)
-        .map_err(ApiError::NotFound)?;
-
-    // Run in task_mgr to avoid race with detach operation
-    let (task_done, wait_task_done) = tokio::sync::oneshot::channel();
-    task_mgr::spawn(
-        &tokio::runtime::Handle::current(),
-        TaskKind::Compaction,
-        Some(tenant_id),
-        Some(timeline_id),
-        &format!(
-            "timeline_compact_handler compaction run for tenant {tenant_id} timeline {timeline_id}"
-        ),
-        false,
-        async move {
-            let result = timeline
-                .compact()
-                .instrument(
-                    info_span!("manual_compact", tenant = %tenant_id, timeline = %timeline_id),
-                )
-                .await;
-
-            match task_done.send(result) {
-                Ok(_) => (),
-                Err(result) => error!("failed to send compaction result: {result:?}"),
-            }
-            Ok(())
-        },
-    );
-
-    // drop the guard until after we've spawned the task so that timeline shutdown will wait for the task
-    drop(guard);
-
-    Ok(wait_task_done)
-}

pageserver/src/tenant/remote_timeline_client.rs

@@ -214,6 +214,7 @@ use anyhow::ensure;
 use remote_storage::{DownloadError, GenericRemoteStorage};
 use std::ops::DerefMut;
 use tokio::runtime::Runtime;
+use tokio_util::sync::CancellationToken;
 use tracing::{debug, info, warn};
 use tracing::{info_span, Instrument};
 use utils::lsn::Lsn;
@@ -225,12 +226,12 @@ use crate::tenant::remote_timeline_client::index::LayerFileMetadata;
 use crate::{
     config::PageServerConf,
     task_mgr,
-    task_mgr::TaskKind,
     task_mgr::BACKGROUND_RUNTIME,
     tenant::metadata::TimelineMetadata,
     tenant::upload_queue::{
         UploadOp, UploadQueue, UploadQueueInitialized, UploadQueueStopped, UploadTask,
     },
+    tenant::TimelineRequestContext,
     {exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS},
 };
 
@@ -313,25 +314,50 @@ 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) -> anyhow::Result<()> {
+    pub fn init_upload_queue(
+        self: &Arc<Self>,
+        index_part: &IndexPart,
+        upload_ctx: TimelineRequestContext,
+    ) -> anyhow::Result<()> {
+        let cancellation_token = upload_ctx.cancellation_token().clone();
         let mut upload_queue = self.upload_queue.lock().unwrap();
-        upload_queue.initialize_with_current_remote_index_part(index_part)?;
+        upload_queue.initialize_with_current_remote_index_part(index_part, upload_ctx)?;
         self.update_remote_physical_size_gauge(Some(index_part));
+        self.spawn_cancellation_watch(cancellation_token);
         Ok(())
     }
 
     /// Initialize the upload queue for the case where the remote storage is empty,
     /// i.e., it doesn't have an `IndexPart`.
     pub fn init_upload_queue_for_empty_remote(
-        &self,
+        self: &Arc<Self>,
         local_metadata: &TimelineMetadata,
+        upload_ctx: TimelineRequestContext,
     ) -> anyhow::Result<()> {
+        let cancellation_token = upload_ctx.cancellation_token().clone();
         let mut upload_queue = self.upload_queue.lock().unwrap();
-        upload_queue.initialize_empty_remote(local_metadata)?;
+        upload_queue.initialize_empty_remote(local_metadata, upload_ctx)?;
         self.update_remote_physical_size_gauge(None);
+        self.spawn_cancellation_watch(cancellation_token);
         Ok(())
     }
 
+    /// Spawn a task that calls `stop` on cancellation. It's important that we
+    /// stop the upload queue promptly, because it holds onto the RequestContext,
+    /// which in turn prevents the Timeline from shutting down.
+    fn spawn_cancellation_watch(self: &Arc<Self>, cancellation_token: CancellationToken) {
+        let self_rc = Arc::clone(self);
+        task_mgr::spawn(
+            self.runtime.handle(),
+            "remote upload queue cancellation watch",
+            false,
+            async move {
+                cancellation_token.cancelled().await;
+                self_rc.stop();
+            },
+        );
+    }
+
     pub fn last_uploaded_consistent_lsn(&self) -> Option<Lsn> {
         match &*self.upload_queue.lock().unwrap() {
             UploadQueue::Uninitialized => None,
@@ -625,7 +651,10 @@ impl RemoteTimelineClient {
     ///
     /// Wait for all previously scheduled uploads/deletions to complete
     ///
-    pub async fn wait_completion(self: &Arc<Self>) -> anyhow::Result<()> {
+    pub async fn wait_completion(
+        self: &Arc<Self>,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         let (sender, mut receiver) = tokio::sync::watch::channel(());
         let barrier_op = UploadOp::Barrier(sender);
 
@@ -639,9 +668,16 @@ impl RemoteTimelineClient {
             self.launch_queued_tasks(upload_queue);
         }
 
-        if receiver.changed().await.is_err() {
-            anyhow::bail!("wait_completion aborted because upload queue was stopped");
-        }
+        tokio::select! {
+            result = receiver.changed() => {
+                if result.is_err() {
+                    anyhow::bail!("wait_completion aborted because upload queue was stopped");
+                }
+            },
+            _ = ctx.cancelled() => {
+                anyhow::bail!("request cancelled while waiting on uploads to finish");
+            },
+        };
         Ok(())
     }
 
@@ -719,16 +755,15 @@ impl RemoteTimelineClient {
 
             // Spawn task to perform the task
             let self_rc = Arc::clone(self);
+
+            let cancellation_token = upload_queue.upload_ctx.cancellation_token().clone();
+
             task_mgr::spawn(
                 self.runtime.handle(),
-                TaskKind::RemoteUploadTask,
-                Some(self.tenant_id),
-                Some(self.timeline_id),
                 "remote upload",
                 false,
                 async move {
-                    self_rc.perform_upload_task(task).await;
-                    Ok(())
+                    self_rc.perform_upload_task(task, cancellation_token).await;
                 }
                 .instrument(info_span!(parent: None, "remote_upload", tenant = %self.tenant_id, timeline = %self.timeline_id, upload_task_id = %task_id)),
             );
@@ -748,7 +783,11 @@ impl RemoteTimelineClient {
     /// The task can be shut down, however. That leads to stopping the whole
     /// queue.
     ///
-    async fn perform_upload_task(self: &Arc<Self>, task: Arc<UploadTask>) {
+    async fn perform_upload_task(
+        self: &Arc<Self>,
+        task: Arc<UploadTask>,
+        cancellation_token: CancellationToken,
+    ) {
         // Loop to retry until it completes.
         loop {
             // If we're requested to shut down, close up shop and exit.
@@ -760,7 +799,7 @@ impl RemoteTimelineClient {
             // the Future, but we're not 100% sure if the remote storage library
             // is cancellation safe, so we don't dare to do that. Hopefully, the
             // upload finishes or times out soon enough.
-            if task_mgr::is_shutdown_requested() {
+            if cancellation_token.is_cancelled() {
                 info!("upload task cancelled by shutdown request");
                 self.calls_unfinished_metric_end(&task.op);
                 self.stop();
@@ -858,7 +897,7 @@ impl RemoteTimelineClient {
 
                     // sleep until it's time to retry, or we're cancelled
                     tokio::select! {
-                        _ = task_mgr::shutdown_watcher() => { },
+                        _ = cancellation_token.cancelled() => { },
                         _ = exponential_backoff(
                             retries,
                             DEFAULT_BASE_BACKOFF_SECONDS,
@@ -1010,7 +1049,9 @@ impl RemoteTimelineClient {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::context::{DownloadBehavior, RequestContext, TaskKind};
     use crate::tenant::harness::{TenantHarness, TIMELINE_ID};
+    use crate::DEFAULT_PG_VERSION;
     use remote_storage::{RemoteStorageConfig, RemoteStorageKind};
     use std::{collections::HashSet, path::Path};
     use utils::lsn::Lsn;
@@ -1029,7 +1070,7 @@ mod tests {
             Lsn(0),
             // Any version will do
             // but it should be consistent with the one in the tests
-            crate::DEFAULT_PG_VERSION,
+            DEFAULT_PG_VERSION,
         );
 
         // go through serialize + deserialize to fix the header, including checksum
@@ -1064,9 +1105,19 @@ mod tests {
     // Test scheduling
     #[test]
     fn upload_scheduling() -> anyhow::Result<()> {
+        // Use a current-thread runtime in the test
+        let runtime = Box::leak(Box::new(
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()?,
+        ));
+        let _entered = runtime.enter();
+
         let harness = TenantHarness::create("upload_scheduling")?;
+        let (tenant, tenant_ctx) = runtime.block_on(harness.load());
+        let (_timeline, timeline_ctx) =
+            tenant.create_empty_timeline(TIMELINE_ID, Lsn(0), DEFAULT_PG_VERSION, &tenant_ctx)?;
         let timeline_path = harness.timeline_path(&TIMELINE_ID);
-        std::fs::create_dir_all(&timeline_path)?;
 
         let remote_fs_dir = harness.conf.workdir.join("remote_fs");
         std::fs::create_dir_all(remote_fs_dir)?;
@@ -1084,14 +1135,6 @@ mod tests {
             storage: RemoteStorageKind::LocalFs(remote_fs_dir.clone()),
         };
 
-        // Use a current-thread runtime in the test
-        let runtime = Box::leak(Box::new(
-            tokio::runtime::Builder::new_current_thread()
-                .enable_all()
-                .build()?,
-        ));
-        let _entered = runtime.enter();
-
         // Test outline:
         //
         // Schedule upload of a bunch of layers. Check that they are started immediately, not queued
@@ -1127,7 +1170,11 @@ mod tests {
         println!("remote_timeline_dir: {}", remote_timeline_dir.display());
 
         let metadata = dummy_metadata(Lsn(0x10));
-        client.init_upload_queue_for_empty_remote(&metadata)?;
+        let upload_ctx = timeline_ctx.register_another(RequestContext::new(
+            TaskKind::RemoteUploadTask,
+            DownloadBehavior::Error,
+        ));
+        client.init_upload_queue_for_empty_remote(&metadata, upload_ctx)?;
 
         // Create a couple of dummy files,  schedule upload for them
         let content_foo = dummy_contents("foo");
@@ -1167,7 +1214,7 @@ mod tests {
         }
 
         // Wait for the uploads to finish
-        runtime.block_on(client.wait_completion())?;
+        runtime.block_on(client.wait_completion(&timeline_ctx))?;
         {
             let mut guard = client.upload_queue.lock().unwrap();
             let upload_queue = guard.initialized_mut().unwrap();
@@ -1204,7 +1251,7 @@ mod tests {
         assert_remote_files(&["foo", "bar", "index_part.json"], &remote_timeline_dir);
 
         // Finish them
-        runtime.block_on(client.wait_completion())?;
+        runtime.block_on(client.wait_completion(&timeline_ctx))?;
 
         assert_remote_files(&["bar", "baz", "index_part.json"], &remote_timeline_dir);
 

pageserver/src/tenant/size.rs

@@ -3,10 +3,9 @@ use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
 
 use anyhow::Context;
-use tokio::sync::oneshot::error::RecvError;
 use tokio::sync::Semaphore;
 
-use crate::pgdatadir_mapping::CalculateLogicalSizeError;
+use crate::tenant::{PageReconstructError, TenantRequestContext, TimelineRequestContext};
 
 use super::Tenant;
 use utils::id::TimelineId;
@@ -63,13 +62,14 @@ pub(super) async fn gather_inputs(
     tenant: &Tenant,
     limit: &Arc<Semaphore>,
     logical_size_cache: &mut HashMap<(TimelineId, Lsn), u64>,
+    tenant_ctx: &TenantRequestContext,
 ) -> anyhow::Result<ModelInputs> {
     // with joinset, on drop, all of the tasks will just be de-scheduled, which we can use to
     // our advantage with `?` error handling.
     let mut joinset = tokio::task::JoinSet::new();
 
     let timelines = tenant
-        .refresh_gc_info()
+        .refresh_gc_info(tenant_ctx)
         .await
         .context("Failed to refresh gc_info before gathering inputs")?;
 
@@ -97,9 +97,21 @@ pub(super) async fn gather_inputs(
     // used to determine the `retention_period` for the size model
     let mut max_cutoff_distance = None;
 
+    let mut ctx_dropguards: Vec<tokio_util::sync::DropGuard> = Vec::new();
+
     for timeline in timelines {
         let last_record_lsn = timeline.get_last_record_lsn();
 
+        let ctx = match timeline.get_context(tenant_ctx) {
+            Ok(ctx) => ctx,
+            Err(state) => {
+                info!("skipping tenant size calculation for timeline because it is in {state:?} state");
+                continue;
+            }
+        };
+        ctx_dropguards.push(ctx.cancellation_token().clone().drop_guard());
+        let ctx = Arc::new(ctx);
+
         let (interesting_lsns, horizon_cutoff, pitr_cutoff, next_gc_cutoff) = {
             // there's a race between the update (holding tenant.gc_lock) and this read but it
             // might not be an issue, because it's not for Timeline::gc
@@ -169,19 +181,23 @@ pub(super) async fn gather_inputs(
             timeline_id: timeline.timeline_id,
         });
 
-        for (lsn, _kind) in &interesting_lsns {
-            if let Some(size) = logical_size_cache.get(&(timeline.timeline_id, *lsn)) {
+        for (lsn, _kind) in interesting_lsns.iter() {
+            let lsn = *lsn;
+            if let Some(size) = logical_size_cache.get(&(timeline.timeline_id, lsn)) {
                 updates.push(Update {
-                    lsn: *lsn,
+                    lsn,
                     timeline_id: timeline.timeline_id,
                     command: Command::Update(*size),
                 });
 
-                needed_cache.insert((timeline.timeline_id, *lsn));
+                needed_cache.insert((timeline.timeline_id, lsn));
             } else {
                 let timeline = Arc::clone(&timeline);
                 let parallel_size_calcs = Arc::clone(limit);
-                joinset.spawn(calculate_logical_size(parallel_size_calcs, timeline, *lsn));
+                let ctx_clone = Arc::clone(&ctx);
+                joinset.spawn(async move {
+                    calculate_logical_size(parallel_size_calcs, timeline, lsn, &ctx_clone).await
+                });
             }
         }
 
@@ -357,7 +373,7 @@ enum LsnKind {
 struct TimelineAtLsnSizeResult(
     Arc<crate::tenant::Timeline>,
     utils::lsn::Lsn,
-    Result<u64, CalculateLogicalSizeError>,
+    Result<u64, PageReconstructError>,
 );
 
 #[instrument(skip_all, fields(timeline_id=%timeline.timeline_id, lsn=%lsn))]
@@ -365,14 +381,13 @@ async fn calculate_logical_size(
     limit: Arc<tokio::sync::Semaphore>,
     timeline: Arc<crate::tenant::Timeline>,
     lsn: utils::lsn::Lsn,
-) -> Result<TimelineAtLsnSizeResult, RecvError> {
+    ctx: &TimelineRequestContext,
+) -> Result<TimelineAtLsnSizeResult, PageReconstructError> {
     let _permit = tokio::sync::Semaphore::acquire_owned(limit)
         .await
-        .expect("global semaphore should not had been closed");
+        .expect("global semaphore should not have been closed");
 
-    let size_res = timeline
-        .spawn_ondemand_logical_size_calculation(lsn)
-        .await?;
+    let size_res = timeline.calculate_logical_size(lsn, ctx).await;
     Ok(TimelineAtLsnSizeResult(timeline, lsn, size_res))
 }
 

pageserver/src/tenant/tasks.rs

@@ -1,45 +1,39 @@
 //! This module contains functions to serve per-tenant background processes,
 //! such as compaction and GC
 
-use std::ops::ControlFlow;
 use std::sync::Arc;
 use std::time::Duration;
 
+use crate::context::{DownloadBehavior, RequestContext, TaskKind};
 use crate::metrics::TENANT_TASK_EVENTS;
 use crate::task_mgr;
-use crate::task_mgr::{TaskKind, BACKGROUND_RUNTIME};
-use crate::tenant::mgr;
-use crate::tenant::{Tenant, TenantState};
+use crate::task_mgr::BACKGROUND_RUNTIME;
+use crate::tenant::Tenant;
 use tracing::*;
-use utils::id::TenantId;
 
-pub fn start_background_loops(tenant_id: TenantId) {
+pub fn start_background_loops(tenant: &Arc<Tenant>) {
+    let tenant_id = tenant.tenant_id;
+
+    let tenant_clone = Arc::clone(tenant);
     task_mgr::spawn(
         BACKGROUND_RUNTIME.handle(),
-        TaskKind::Compaction,
-        Some(tenant_id),
-        None,
         &format!("compactor for tenant {tenant_id}"),
         false,
         async move {
-            compaction_loop(tenant_id)
+            compaction_loop(&tenant_clone)
                 .instrument(info_span!("compaction_loop", tenant_id = %tenant_id))
                 .await;
-            Ok(())
         },
     );
+    let tenant_clone = Arc::clone(tenant);
     task_mgr::spawn(
         BACKGROUND_RUNTIME.handle(),
-        TaskKind::GarbageCollector,
-        Some(tenant_id),
-        None,
         &format!("garbage collector for tenant {tenant_id}"),
         false,
         async move {
-            gc_loop(tenant_id)
+            gc_loop(&tenant_clone)
                 .instrument(info_span!("gc_loop", tenant_id = %tenant_id))
                 .await;
-            Ok(())
         },
     );
 }
@@ -47,25 +41,27 @@ pub fn start_background_loops(tenant_id: TenantId) {
 ///
 /// Compaction task's main loop
 ///
-async fn compaction_loop(tenant_id: TenantId) {
+async fn compaction_loop(tenant: &Arc<Tenant>) {
     let wait_duration = Duration::from_secs(2);
     info!("starting");
     TENANT_TASK_EVENTS.with_label_values(&["start"]).inc();
     async {
+        let top_ctx = RequestContext::new(TaskKind::Compaction, DownloadBehavior::Download);
+
+        let tenant_ctx = match tenant.get_context(&top_ctx) {
+            Ok(ctx) => ctx,
+            Err(state) => {
+                // This could happen if the tenant is detached or the pageserver is shut
+                // down immediately after loading or attaching completed and the tenant
+                // was activated. It seems unlikely enough in practice that we better print
+                // a warning, as it could also be a bug.
+                error!("Not running compaction loop, tenant is not active: {state:?}");
+                return;
+            }
+        };
         loop {
             trace!("waking up");
 
-            let tenant = tokio::select! {
-                _ = task_mgr::shutdown_watcher() => {
-                    info!("received cancellation request");
-                    return;
-                },
-                tenant_wait_result = wait_for_active_tenant(tenant_id, wait_duration) => match tenant_wait_result {
-                    ControlFlow::Break(()) => return,
-                    ControlFlow::Continue(tenant) => tenant,
-                },
-            };
-
             let mut sleep_duration = tenant.get_compaction_period();
             if sleep_duration == Duration::ZERO {
                 info!("automatic compaction is disabled");
@@ -73,7 +69,7 @@ async fn compaction_loop(tenant_id: TenantId) {
                 sleep_duration = Duration::from_secs(10);
             } else {
                 // Run compaction
-                if let Err(e) = tenant.compaction_iteration().await {
+                if let Err(e) = tenant.compaction_iteration(&tenant_ctx).await {
                     sleep_duration = wait_duration;
                     error!("Compaction failed, retrying in {:?}: {e:?}", sleep_duration);
                 }
@@ -81,7 +77,7 @@ async fn compaction_loop(tenant_id: TenantId) {
 
             // Sleep
             tokio::select! {
-                _ = task_mgr::shutdown_watcher() => {
+                _ = tenant_ctx.cancelled() => {
                     info!("received cancellation request during idling");
                     break;
                 },
@@ -98,25 +94,28 @@ async fn compaction_loop(tenant_id: TenantId) {
 ///
 /// GC task's main loop
 ///
-async fn gc_loop(tenant_id: TenantId) {
+async fn gc_loop(tenant: &Arc<Tenant>) {
     let wait_duration = Duration::from_secs(2);
     info!("starting");
     TENANT_TASK_EVENTS.with_label_values(&["start"]).inc();
     async {
+        // GC might require downloading, to find the cutoff LSN that corresponds to the
+        // cutoff specified as time.
+        let top_ctx = RequestContext::new(TaskKind::GarbageCollector, DownloadBehavior::Download);
+        let tenant_ctx = match tenant.get_context(&top_ctx) {
+            Ok(ctx) => ctx,
+            Err(state) => {
+                // This could happen if the tenant is detached or the pageserver is shut
+                // down immediately after loading or attaching completed and the tenant
+                // was activated. It seems unlikely enough in practice that we better print
+                // a warning, as it could also be a bug.
+                error!("Not running GC loop, tenant is not active: {state:?}");
+                return;
+            }
+        };
         loop {
             trace!("waking up");
 
-            let tenant = tokio::select! {
-                _ = task_mgr::shutdown_watcher() => {
-                    info!("received cancellation request");
-                    return;
-                },
-                tenant_wait_result = wait_for_active_tenant(tenant_id, wait_duration) => match tenant_wait_result {
-                    ControlFlow::Break(()) => return,
-                    ControlFlow::Continue(tenant) => tenant,
-                },
-            };
-
             let gc_period = tenant.get_gc_period();
             let gc_horizon = tenant.get_gc_horizon();
             let mut sleep_duration = gc_period;
@@ -127,7 +126,10 @@ async fn gc_loop(tenant_id: TenantId) {
             } else {
                 // Run gc
                 if gc_horizon > 0 {
-                    if let Err(e) = tenant.gc_iteration(None, gc_horizon, tenant.get_pitr_interval()).await
+                    // Run compaction
+                    if let Err(e) = tenant
+                        .gc_iteration(None, gc_horizon, tenant.get_pitr_interval(), &tenant_ctx)
+                        .await
                     {
                         sleep_duration = wait_duration;
                         error!("Gc failed, retrying in {:?}: {e:?}", sleep_duration);
@@ -137,7 +139,7 @@ async fn gc_loop(tenant_id: TenantId) {
 
             // Sleep
             tokio::select! {
-                _ = task_mgr::shutdown_watcher() => {
+                _ = tenant_ctx.cancelled() => {
                     info!("received cancellation request during idling");
                     break;
                 },
@@ -149,46 +151,3 @@ async fn gc_loop(tenant_id: TenantId) {
     TENANT_TASK_EVENTS.with_label_values(&["stop"]).inc();
     trace!("GC loop stopped.");
 }
-
-async fn wait_for_active_tenant(
-    tenant_id: TenantId,
-    wait: Duration,
-) -> ControlFlow<(), Arc<Tenant>> {
-    let tenant = loop {
-        match mgr::get_tenant(tenant_id, false).await {
-            Ok(tenant) => break tenant,
-            Err(e) => {
-                error!("Failed to get a tenant {tenant_id}: {e:#}");
-                tokio::time::sleep(wait).await;
-            }
-        }
-    };
-
-    // if the tenant has a proper status already, no need to wait for anything
-    if tenant.current_state() == TenantState::Active {
-        ControlFlow::Continue(tenant)
-    } else {
-        let mut tenant_state_updates = tenant.subscribe_for_state_updates();
-        loop {
-            match tenant_state_updates.changed().await {
-                Ok(()) => {
-                    let new_state = *tenant_state_updates.borrow();
-                    match new_state {
-                        TenantState::Active => {
-                            debug!("Tenant state changed to active, continuing the task loop");
-                            return ControlFlow::Continue(tenant);
-                        }
-                        state => {
-                            debug!("Not running the task loop, tenant is not active: {state:?}");
-                            continue;
-                        }
-                    }
-                }
-                Err(_sender_dropped_error) => {
-                    info!("Tenant dropped the state updates sender, quitting waiting for tenant and the task loop");
-                    return ControlFlow::Break(());
-                }
-            }
-        }
-    }
-}

pageserver/src/tenant/timeline.rs

@@ -10,8 +10,7 @@ use once_cell::sync::OnceCell;
 use pageserver_api::models::{
     DownloadRemoteLayersTaskInfo, DownloadRemoteLayersTaskState, TimelineState,
 };
-use tokio::sync::{oneshot, watch, Semaphore, TryAcquireError};
-use tokio_util::sync::CancellationToken;
+use tokio::sync::{watch, Semaphore, TryAcquireError};
 use tracing::*;
 
 use std::cmp::{max, min, Ordering};
@@ -23,6 +22,7 @@ use std::sync::atomic::{AtomicI64, Ordering as AtomicOrdering};
 use std::sync::{Arc, Mutex, MutexGuard, RwLock, Weak};
 use std::time::{Duration, Instant, SystemTime};
 
+use crate::context::{DownloadBehavior, RequestContext, RequestContextId, TaskKind};
 use crate::tenant::remote_timeline_client::{self, index::LayerFileMetadata};
 use crate::tenant::storage_layer::{
     DeltaFileName, DeltaLayerWriter, ImageFileName, ImageLayerWriter, InMemoryLayer, LayerFileName,
@@ -34,14 +34,15 @@ use crate::tenant::{
     metadata::{save_metadata, TimelineMetadata},
     par_fsync,
     storage_layer::{PersistentLayer, ValueReconstructResult, ValueReconstructState},
+    TenantRequestContext,
 };
 
 use crate::config::PageServerConf;
 use crate::keyspace::{KeyPartitioning, KeySpace};
 use crate::metrics::TimelineMetrics;
+use crate::pgdatadir_mapping::BlockNumber;
 use crate::pgdatadir_mapping::LsnForTimestamp;
 use crate::pgdatadir_mapping::{is_rel_fsm_block_key, is_rel_vm_block_key};
-use crate::pgdatadir_mapping::{BlockNumber, CalculateLogicalSizeError};
 use crate::tenant::config::TenantConfOpt;
 use pageserver_api::reltag::RelTag;
 
@@ -57,7 +58,6 @@ use utils::{
 use crate::page_cache;
 use crate::repository::GcResult;
 use crate::repository::{Key, Value};
-use crate::task_mgr::TaskKind;
 use crate::walreceiver::{is_broker_client_initialized, spawn_connection_manager_task};
 use crate::walredo::WalRedoManager;
 use crate::METADATA_FILE_NAME;
@@ -190,6 +190,10 @@ pub struct Timeline {
     download_all_remote_layers_task_info: RwLock<Option<DownloadRemoteLayersTaskInfo>>,
 
     state: watch::Sender<TimelineState>,
+
+    /// RequestContexts associated with this timeline. Used on
+    /// shutdown, to cancel and wait for operations to finish.
+    active_contexts: Mutex<HashMap<RequestContextId, TaskKind>>,
 }
 
 /// Internal structure to hold all data needed for logical size calculation.
@@ -377,6 +381,12 @@ pub enum PageReconstructError {
     #[error(transparent)]
     Other(#[from] anyhow::Error), // source and Display delegate to anyhow::Error
 
+    /// The operation would require downloading a layer that is missing locally.
+    NeedsDownload(Weak<Timeline>, Weak<RemoteLayer>),
+
+    /// The operation was cancelled
+    Cancelled,
+
     /// An error happened replaying WAL records
     #[error(transparent)]
     WalRedo(#[from] crate::walredo::WalRedoError),
@@ -386,6 +396,19 @@ impl std::fmt::Debug for PageReconstructError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
         match self {
             Self::Other(err) => err.fmt(f),
+            Self::NeedsDownload(_tli, _layer) => write!(f, "needs download"),
+            Self::Cancelled => write!(f, "cancelled"),
+            Self::WalRedo(err) => err.fmt(f),
+        }
+    }
+}
+
+impl std::fmt::Display for PageReconstructError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        match self {
+            Self::Other(err) => err.fmt(f),
+            Self::NeedsDownload(_tli, _layer) => write!(f, "needs download"),
+            Self::Cancelled => write!(f, "cancelled"),
             Self::WalRedo(err) => err.fmt(f),
         }
     }
@@ -410,6 +433,79 @@ impl Timeline {
         self.latest_gc_cutoff_lsn.read()
     }
 
+    /// similar to Tenant::register_context
+    pub fn register_context(
+        &self,
+        tenant_ctx: TenantRequestContext,
+    ) -> Result<TimelineRequestContext, TimelineState> {
+        let state_ref = self.state.borrow();
+        let state = *state_ref;
+
+        if state == TimelineState::Active || state == TimelineState::Suspended {
+            if self
+                .active_contexts
+                .lock()
+                .unwrap()
+                .insert(tenant_ctx.ctx.context_id(), tenant_ctx.ctx.task_kind())
+                .is_some()
+            {
+                panic!("active_contexts out of sync");
+            }
+            let timeline_ctx = TimelineRequestContext {
+                ctx: tenant_ctx,
+                timeline: self.myself.upgrade().unwrap(),
+            };
+            Ok(timeline_ctx)
+        } else {
+            Err(state)
+        }
+    }
+
+    pub fn get_context(
+        &self,
+        tenant_ctx: &TenantRequestContext,
+    ) -> Result<TimelineRequestContext, TimelineState> {
+        self.register_context(tenant_ctx.register_another(RequestContext::with_parent(
+            tenant_ctx.task_kind(),
+            tenant_ctx.download_behavior(),
+            &tenant_ctx.ctx,
+        )))
+    }
+
+    fn deregister_context(&self, context_id: RequestContextId) {
+        if self
+            .active_contexts
+            .lock()
+            .unwrap()
+            .remove(&context_id)
+            .is_none()
+        {
+            panic!("active_contexts out of sync");
+        }
+    }
+
+    ///
+    /// Wait until all RequestContexts registered with the Timeline have been dropped.
+    ///
+    /// This should be called only after setting the state to Stopping. Otherwise
+    /// new contexts can appear at any time.
+    ///
+    pub async fn wait_no_more_active_contexts(&self) {
+        let mut retries = 0;
+        loop {
+            if self.active_contexts.lock().unwrap().is_empty() {
+                return;
+            }
+            crate::exponential_backoff(
+                retries,
+                crate::DEFAULT_BASE_BACKOFF_SECONDS,
+                crate::DEFAULT_MAX_BACKOFF_SECONDS,
+            )
+            .await;
+            retries += 1;
+        }
+    }
+
     /// Look up given page version.
     ///
     /// If a remote layer file is needed, it is downloaded as part of this
@@ -422,7 +518,12 @@ impl Timeline {
     /// an ancestor branch, for example, or waste a lot of cycles chasing the
     /// non-existing key.
     ///
-    pub async fn get(&self, key: Key, lsn: Lsn) -> Result<Bytes, PageReconstructError> {
+    pub async fn get(
+        &self,
+        key: Key,
+        lsn: Lsn,
+        ctx: &TimelineRequestContext,
+    ) -> Result<Bytes, PageReconstructError> {
         if !lsn.is_valid() {
             return Err(PageReconstructError::Other(anyhow::anyhow!("Invalid LSN")));
         }
@@ -450,7 +551,7 @@ impl Timeline {
             img: cached_page_img,
         };
 
-        self.get_reconstruct_data(key, lsn, &mut reconstruct_state)
+        self.get_reconstruct_data(key, lsn, &mut reconstruct_state, ctx)
             .await?;
 
         self.metrics
@@ -513,13 +614,14 @@ impl Timeline {
     /// You should call this before any of the other get_* or list_* functions. Calling
     /// those functions with an LSN that has been processed yet is an error.
     ///
-    pub async fn wait_lsn(&self, lsn: Lsn) -> anyhow::Result<()> {
+    /// TODO: also return if 'ctx' is cancelled
+    pub async fn wait_lsn(&self, lsn: Lsn, ctx: &TimelineRequestContext) -> anyhow::Result<()> {
         anyhow::ensure!(self.is_active(), "Cannot wait for Lsn on inactive timeline");
 
         // This should never be called from the WAL receiver, because that could lead
         // to a deadlock.
         anyhow::ensure!(
-            task_mgr::current_task_kind() != Some(TaskKind::WalReceiverConnection),
+            ctx.task_kind() != TaskKind::WalReceiverConnection,
             "wait_lsn cannot be called in WAL receiver"
         );
 
@@ -558,7 +660,7 @@ impl Timeline {
         self.flush_frozen_layers_and_wait().await
     }
 
-    pub async fn compact(&self) -> anyhow::Result<()> {
+    pub async fn compact(&self, ctx: &TimelineRequestContext) -> anyhow::Result<()> {
         let last_record_lsn = self.get_last_record_lsn();
 
         // Last record Lsn could be zero in case the timeline was just created
@@ -616,14 +718,16 @@ impl Timeline {
             .repartition(
                 self.get_last_record_lsn(),
                 self.get_compaction_target_size(),
+                ctx,
             )
             .await
         {
             Ok((partitioning, lsn)) => {
                 // 2. Create new image layers for partitions that have been modified
                 // "enough".
-                let layer_paths_to_upload =
-                    self.create_image_layers(&partitioning, lsn, false).await?;
+                let layer_paths_to_upload = self
+                    .create_image_layers(&partitioning, lsn, false, ctx)
+                    .await?;
                 if let Some(remote_client) = &self.remote_client {
                     for (path, layer_metadata) in layer_paths_to_upload {
                         remote_client.schedule_layer_file_upload(&path, &layer_metadata)?;
@@ -632,7 +736,7 @@ impl Timeline {
 
                 // 3. Compact
                 let timer = self.metrics.compact_time_histo.start_timer();
-                self.compact_level0(target_file_size).await?;
+                self.compact_level0(target_file_size, ctx).await?;
                 timer.stop_and_record();
 
                 // If `create_image_layers' or `compact_level0` scheduled any
@@ -673,7 +777,10 @@ impl Timeline {
     /// the initial size calculation has not been run (gets triggered on the first size access).
     ///
     /// return size and boolean flag that shows if the size is exact
-    pub fn get_current_logical_size(self: &Arc<Self>) -> anyhow::Result<(u64, bool)> {
+    pub fn get_current_logical_size(
+        self: &Arc<Self>,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<(u64, bool)> {
         let current_size = self.current_logical_size.current_size()?;
         debug!("Current size: {current_size:?}");
 
@@ -683,7 +790,7 @@ impl Timeline {
             (current_size, self.current_logical_size.initial_part_end)
         {
             is_exact = false;
-            self.try_spawn_size_init_task(init_lsn);
+            self.try_spawn_size_init_task(init_lsn, ctx);
         }
 
         Ok((size, is_exact))
@@ -881,13 +988,81 @@ impl Timeline {
                 download_all_remote_layers_task_info: RwLock::new(None),
 
                 state,
+
+                active_contexts: Mutex::new(HashMap::new()),
             };
             result.repartition_threshold = result.get_checkpoint_distance() / 10;
             result
         })
     }
 
-    pub(super) fn maybe_spawn_flush_loop(self: &Arc<Self>) {
+    async fn graceful_shutdown_phase(&self, phase: u32) {
+        let mut contexts_to_kill = Vec::new();
+        {
+            let active_contexts = self.active_contexts.lock().unwrap();
+            for (&context_id, &task_kind) in active_contexts.iter() {
+                let this_phase = match task_kind {
+                    TaskKind::UnitTest => 1,
+
+                    // First shut down all client connections and
+                    // management request.
+                    // Also, if we were still doing the initial load or
+                    // attach operation, cancel that.
+                    // Also stop compaction and GC background tasks.
+                    //
+                    // Also stop WAL receiver immediately. A client
+                    // request could be waiting for new WAL to arrive,
+                    // but we're cancelling all such requests too.
+                    TaskKind::LibpqEndpointListener
+                    | TaskKind::HttpEndpointListener
+                    | TaskKind::PageRequestHandler
+                    | TaskKind::MgmtRequest
+                    | TaskKind::GarbageCollector
+                    | TaskKind::Compaction
+                    | TaskKind::InitialLogicalSizeCalculation
+                    | TaskKind::InitialLoad
+                    | TaskKind::Attach
+                    | TaskKind::DownloadAllRemoteLayers
+                    | TaskKind::RemoteDownloadTask
+                    | TaskKind::WalReceiverConnection
+                    | TaskKind::WalReceiverManager => 1,
+
+                    // There is no more incoming WAL.
+                    TaskKind::LayerFlush => 2,
+                    // FIXME: should we wait for in-progress uploads to finish?
+                    // With a timeout?
+                    TaskKind::RemoteUploadTask => 2,
+
+                    TaskKind::MetricsCollection => 3,
+                };
+                if this_phase == phase {
+                    contexts_to_kill.push(context_id);
+                }
+            }
+        }
+        crate::context::cancel_and_wait(&mut contexts_to_kill).await;
+    }
+
+    pub(super) async fn graceful_shutdown(&self, flush: bool) {
+        let state = *self.state.borrow();
+        assert!(
+            state == TimelineState::Stopping || state == TimelineState::Suspended,
+            "graceful_shutdown called on timeline in state {state:?}"
+        );
+
+        self.graceful_shutdown_phase(1).await;
+        if flush {
+            if let Err(err) = self.freeze_and_flush().await {
+                error!("error flushing in-memory data during shutdown: {err:?}");
+                // Continue with the shutdown anyway, it's the best we can do
+            }
+        }
+
+        self.graceful_shutdown_phase(2).await;
+        self.graceful_shutdown_phase(3).await;
+    }
+
+    pub(super) fn maybe_spawn_flush_loop(self: &Arc<Self>, ctx: &TimelineRequestContext) {
         let mut flush_loop_state = self.flush_loop_state.lock().unwrap();
         match *flush_loop_state {
             FlushLoopState::NotStarted => (),
@@ -909,27 +1084,30 @@ impl Timeline {
 
         let layer_flush_start_rx = self.layer_flush_start_tx.subscribe();
         let self_clone = Arc::clone(self);
+
+        let background_ctx = ctx.register_another(RequestContext::new(
+            TaskKind::LayerFlush,
+            DownloadBehavior::Error,
+        ));
+
         info!("spawning flush loop");
         task_mgr::spawn(
-                    task_mgr::BACKGROUND_RUNTIME.handle(),
-                    task_mgr::TaskKind::LayerFlushTask,
-                    Some(self.tenant_id),
-                    Some(self.timeline_id),
-                    "layer flush task",
-                    false,
-                    async move {
-                         self_clone.flush_loop(layer_flush_start_rx).await;
-                         let mut flush_loop_state = self_clone.flush_loop_state.lock().unwrap();
-                         assert_eq!(*flush_loop_state, FlushLoopState::Running);
-                         *flush_loop_state  = FlushLoopState::Exited;
-                         Ok(()) }
-                    .instrument(info_span!(parent: None, "layer flush task", tenant = %self.tenant_id, timeline = %self.timeline_id))
-                );
+            task_mgr::BACKGROUND_RUNTIME.handle(),
+            "layer flush task",
+            false,
+            async move {
+                self_clone.flush_loop(layer_flush_start_rx, &background_ctx).await;
+                let mut flush_loop_state = self_clone.flush_loop_state.lock().unwrap();
+                assert_eq!(*flush_loop_state, FlushLoopState::Running);
+                *flush_loop_state  = FlushLoopState::Exited;
+            }
+            .instrument(info_span!(parent: None, "layer flush task", tenant = %self.tenant_id, timeline = %self.timeline_id))
+        );
 
         *flush_loop_state = FlushLoopState::Running;
     }
 
-    pub(super) fn launch_wal_receiver(self: &Arc<Self>) {
+    pub(super) fn launch_wal_receiver(self: &Arc<Self>, ctx: &TimelineRequestContext) {
         if !is_broker_client_initialized() {
             if cfg!(test) {
                 info!("not launching WAL receiver because broker client hasn't been initialized");
@@ -939,6 +1117,11 @@ impl Timeline {
             }
         }
 
+        let background_ctx = ctx.register_another(RequestContext::new(
+            TaskKind::WalReceiverManager,
+            DownloadBehavior::Error,
+        ));
+
         info!(
             "launching WAL receiver for timeline {} of tenant {}",
             self.timeline_id, self.tenant_id
@@ -961,6 +1144,7 @@ impl Timeline {
             lagging_wal_timeout,
             max_lsn_wal_lag,
             crate::config::SAFEKEEPER_AUTH_TOKEN.get().cloned(),
+            background_ctx,
         );
     }
 
@@ -1220,11 +1404,12 @@ impl Timeline {
     /// # TODO
     /// May be a bit cleaner to do things based on populated remote client,
     /// and then do things based on its upload_queue.latest_files.
-    #[instrument(skip(self, index_part, up_to_date_metadata))]
+    #[instrument(skip(self, index_part, up_to_date_metadata, ctx))]
     pub async fn reconcile_with_remote(
         &self,
         up_to_date_metadata: &TimelineMetadata,
         index_part: Option<&IndexPart>,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         info!("starting");
         let remote_client = self
@@ -1242,19 +1427,24 @@ impl Timeline {
             .map(|l| (l.filename(), l))
             .collect::<HashMap<_, _>>();
 
+        let upload_ctx = ctx.register_another(RequestContext::new(
+            TaskKind::RemoteUploadTask,
+            DownloadBehavior::Error,
+        ));
         let local_only_layers = match index_part {
             Some(index_part) => {
                 info!(
                     "initializing upload queue from remote index with {} layer files",
                     index_part.timeline_layers.len()
                 );
-                remote_client.init_upload_queue(index_part)?;
+                remote_client.init_upload_queue(index_part, upload_ctx)?;
                 self.create_remote_layers(index_part, local_layers, disk_consistent_lsn)
                     .await?
             }
             None => {
                 info!("initializing upload queue as empty");
-                remote_client.init_upload_queue_for_empty_remote(up_to_date_metadata)?;
+                remote_client
+                    .init_upload_queue_for_empty_remote(up_to_date_metadata, upload_ctx)?;
                 local_layers
             }
         };
@@ -1280,7 +1470,7 @@ impl Timeline {
         Ok(())
     }
 
-    fn try_spawn_size_init_task(self: &Arc<Self>, init_lsn: Lsn) {
+    fn try_spawn_size_init_task(self: &Arc<Self>, init_lsn: Lsn, ctx: &TimelineRequestContext) {
         let permit = match Arc::clone(&self.current_logical_size.initial_size_computation)
             .try_acquire_owned()
         {
@@ -1298,26 +1488,35 @@ impl Timeline {
             .is_none());
         // We need to start the computation task.
         let self_clone = Arc::clone(self);
+        let background_ctx = ctx.register_another(RequestContext::new(
+            TaskKind::InitialLogicalSizeCalculation,
+            DownloadBehavior::Download,
+        ));
         task_mgr::spawn(
             task_mgr::BACKGROUND_RUNTIME.handle(),
-            task_mgr::TaskKind::InitialLogicalSizeCalculation,
-            Some(self.tenant_id),
-            Some(self.timeline_id),
             "initial size calculation",
             false,
             // NB: don't log errors here, task_mgr will do that.
             async move {
-                let calculated_size = match self_clone.logical_size_calculation_task(init_lsn).await
+                let calculated_size = match self_clone
+                    .calculate_logical_size(init_lsn, &background_ctx)
+                    .await
                 {
                     Ok(s) => s,
-                    Err(CalculateLogicalSizeError::Cancelled) => {
+                    Err(PageReconstructError::Cancelled) => {
                         // Don't make noise, this is a common task.
                         // In the unlikely case that there ihs another call to this function, we'll retry
                         // because initial_logical_size is still None.
                         info!("initial size calculation cancelled, likely timeline delete / tenant detach");
-                        return Ok(());
+                        return;
+                    }
+                    Err(err) => {
+                        error!(
+                            "initial size calculation for {}/{} failed: {:?}",
+                            self_clone.tenant_id, self_clone.timeline_id, err
+                        );
+                        return;
                     }
-                    x @ Err(_) => x.context("Failed to calculate logical size")?,
                 };
                 match self_clone
                     .current_logical_size
@@ -1334,109 +1533,19 @@ impl Timeline {
                 // now that `initial_logical_size.is_some()`, reduce permit count to 0
                 // so that we prevent future callers from spawning this task
                 permit.forget();
-                Ok(())
             },
         );
     }
 
-    pub fn spawn_ondemand_logical_size_calculation(
-        self: &Arc<Self>,
-        lsn: Lsn,
-    ) -> oneshot::Receiver<Result<u64, CalculateLogicalSizeError>> {
-        let (sender, receiver) = oneshot::channel();
-        let self_clone = Arc::clone(self);
-        task_mgr::spawn(
-            task_mgr::BACKGROUND_RUNTIME.handle(),
-            task_mgr::TaskKind::InitialLogicalSizeCalculation,
-            Some(self.tenant_id),
-            Some(self.timeline_id),
-            "ondemand logical size calculation",
-            false,
-            async move {
-                let res = self_clone.logical_size_calculation_task(lsn).await;
-                let _ = sender.send(res).ok();
-                Ok(()) // Receiver is responsible for handling errors
-            },
-        );
-        receiver
-    }
-
-    #[instrument(skip_all, fields(tenant = %self.tenant_id, timeline = %self.timeline_id))]
-    async fn logical_size_calculation_task(
-        self: &Arc<Self>,
-        init_lsn: Lsn,
-    ) -> Result<u64, CalculateLogicalSizeError> {
-        let mut timeline_state_updates = self.subscribe_for_state_updates();
-        let self_calculation = Arc::clone(self);
-        let cancel = CancellationToken::new();
-
-        let calculation = async {
-            let cancel = cancel.child_token();
-            tokio::task::spawn_blocking(move || {
-                // Run in a separate thread since this can do a lot of
-                // synchronous file IO without .await inbetween
-                // if there are no RemoteLayers that would require downloading.
-                let h = tokio::runtime::Handle::current();
-                h.block_on(self_calculation.calculate_logical_size(init_lsn, cancel))
-            })
-            .await
-            .context("Failed to spawn calculation result task")?
-        };
-        let timeline_state_cancellation = async {
-            loop {
-                match timeline_state_updates.changed().await {
-                    Ok(()) => {
-                        let new_state = *timeline_state_updates.borrow();
-                        match new_state {
-                            // we're running this job for active timelines only
-                            TimelineState::Active => continue,
-                            TimelineState::Broken
-                            | TimelineState::Stopping
-                            | TimelineState::Suspended => {
-                                break format!("aborted because timeline became inactive (new state: {new_state:?})")
-                            }
-                        }
-                    }
-                    Err(_sender_dropped_error) => {
-                        // can't happen, the sender is not dropped as long as the Timeline exists
-                        break "aborted because state watch was dropped".to_string();
-                    }
-                }
-            }
-        };
-
-        let taskmgr_shutdown_cancellation = async {
-            task_mgr::shutdown_watcher().await;
-            "aborted because task_mgr shutdown requested".to_string()
-        };
-
-        tokio::pin!(calculation);
-        loop {
-            tokio::select! {
-                res = &mut calculation =>  { return res }
-                reason = timeline_state_cancellation => {
-                    debug!(reason = reason, "cancelling calculation");
-                    cancel.cancel();
-                    return calculation.await;
-                }
-                reason = taskmgr_shutdown_cancellation => {
-                    debug!(reason = reason, "cancelling calculation");
-                    cancel.cancel();
-                    return calculation.await;
-                }
-            }
-        }
-    }
-
     /// Calculate the logical size of the database at the latest LSN.
     ///
     /// NOTE: counted incrementally, includes ancestors. This can be a slow operation,
     /// especially if we need to download remote layers.
-    async fn calculate_logical_size(
+    pub async fn calculate_logical_size(
         &self,
         up_to_lsn: Lsn,
-        cancel: CancellationToken,
-    ) -> Result<u64, CalculateLogicalSizeError> {
+        ctx: &TimelineRequestContext,
+    ) -> Result<u64, PageReconstructError> {
         info!(
             "Calculating logical size for timeline {} at {}",
             self.timeline_id, up_to_lsn
@@ -1478,7 +1587,7 @@ impl Timeline {
             self.metrics.logical_size_histo.start_timer()
         };
         let logical_size = self
-            .get_current_logical_size_non_incremental(up_to_lsn, cancel)
+            .get_current_logical_size_non_incremental(up_to_lsn, ctx)
             .await?;
         debug!("calculated logical size: {logical_size}");
         timer.stop_and_record();
@@ -1555,6 +1664,7 @@ impl Timeline {
         key: Key,
         request_lsn: Lsn,
         reconstruct_state: &mut ValueReconstructState,
+        ctx: &TimelineRequestContext,
     ) -> Result<(), PageReconstructError> {
         // Start from the current timeline.
         let mut timeline_owned;
@@ -1747,9 +1857,24 @@ impl Timeline {
                 // The next layer doesn't exist locally. Need to download it.
                 // (The control flow is a bit complicated here because we must drop the 'layers'
                 // lock before awaiting on the Future.)
-                info!("on-demand downloading remote layer {id}");
-                timeline.download_remote_layer(remote_layer).await?;
-                continue 'layer_map_search;
+                match ctx.download_behavior() {
+                    DownloadBehavior::Download => {
+                        info!("on-demand downloading remote layer {id}");
+                        timeline.download_remote_layer(remote_layer).await?;
+                        continue 'layer_map_search;
+                    }
+                    DownloadBehavior::Warn => {
+                        warn!("unexpectedly on-demand downloading remote layer {id}");
+                        timeline.download_remote_layer(remote_layer).await?;
+                        continue 'layer_map_search;
+                    }
+                    DownloadBehavior::Error => {
+                        return Err(PageReconstructError::NeedsDownload(
+                            timeline.myself.clone(),
+                            Arc::downgrade(&remote_layer),
+                        ))
+                    }
+                }
             }
         }
     }
@@ -1871,11 +1996,15 @@ impl Timeline {
     }
 
     /// Layer flusher task's main loop.
-    async fn flush_loop(&self, mut layer_flush_start_rx: tokio::sync::watch::Receiver<u64>) {
+    async fn flush_loop(
+        &self,
+        mut layer_flush_start_rx: tokio::sync::watch::Receiver<u64>,
+        ctx: &TimelineRequestContext,
+    ) {
         info!("started flush loop");
         loop {
             tokio::select! {
-                _ = task_mgr::shutdown_watcher() => {
+                _ = ctx.cancelled() => {
                     info!("shutting down layer flush task");
                     break;
                 },
@@ -1892,7 +2021,7 @@ impl Timeline {
                     // drop 'layers' lock to allow concurrent reads and writes
                 };
                 if let Some(layer_to_flush) = layer_to_flush {
-                    if let Err(err) = self.flush_frozen_layer(layer_to_flush).await {
+                    if let Err(err) = self.flush_frozen_layer(layer_to_flush, ctx).await {
                         error!("could not flush frozen layer: {err:?}");
                         break Err(err);
                     }
@@ -1957,8 +2086,12 @@ impl Timeline {
     }
 
     /// Flush one frozen in-memory layer to disk, as a new delta layer.
-    #[instrument(skip(self, frozen_layer), fields(tenant_id=%self.tenant_id, timeline_id=%self.timeline_id, layer=%frozen_layer.short_id()))]
-    async fn flush_frozen_layer(&self, frozen_layer: Arc<InMemoryLayer>) -> anyhow::Result<()> {
+    #[instrument(skip(self, frozen_layer, ctx), fields(tenant_id=%self.tenant_id, timeline_id=%self.timeline_id, layer=%frozen_layer.short_id()))]
+    async fn flush_frozen_layer(
+        &self,
+        frozen_layer: Arc<InMemoryLayer>,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         // As a special case, when we have just imported an image into the repository,
         // instead of writing out a L0 delta layer, we directly write out image layer
         // files instead. This is possible as long as *all* the data imported into the
@@ -1966,10 +2099,12 @@ impl Timeline {
         let lsn_range = frozen_layer.get_lsn_range();
         let layer_paths_to_upload =
             if lsn_range.start == self.initdb_lsn && lsn_range.end == Lsn(self.initdb_lsn.0 + 1) {
+                // Note: The 'ctx' in use here has DownloadBehavior::Error. We should not
+                // require downloading anything during initial import.
                 let (partitioning, _lsn) = self
-                    .repartition(self.initdb_lsn, self.get_compaction_target_size())
+                    .repartition(self.initdb_lsn, self.get_compaction_target_size(), ctx)
                     .await?;
-                self.create_image_layers(&partitioning, self.initdb_lsn, true)
+                self.create_image_layers(&partitioning, self.initdb_lsn, true, ctx)
                     .await?
             } else {
                 // normal case, write out a L0 delta layer file.
@@ -2119,6 +2254,7 @@ impl Timeline {
         &self,
         lsn: Lsn,
         partition_size: u64,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<(KeyPartitioning, Lsn)> {
         {
             let partitioning_guard = self.partitioning.lock().unwrap();
@@ -2129,7 +2265,7 @@ impl Timeline {
                 return Ok((partitioning_guard.0.clone(), partitioning_guard.1));
             }
         }
-        let keyspace = self.collect_keyspace(lsn).await?;
+        let keyspace = self.collect_keyspace(lsn, ctx).await?;
         let partitioning = keyspace.partition(partition_size);
 
         let mut partitioning_guard = self.partitioning.lock().unwrap();
@@ -2187,6 +2323,7 @@ impl Timeline {
         partitioning: &KeyPartitioning,
         lsn: Lsn,
         force: bool,
+        ctx: &TimelineRequestContext,
     ) -> Result<HashMap<LayerFileName, LayerFileMetadata>, PageReconstructError> {
         let timer = self.metrics.create_images_time_histo.start_timer();
         let mut image_layers: Vec<ImageLayer> = Vec::new();
@@ -2211,7 +2348,7 @@ impl Timeline {
                 for range in &partition.ranges {
                     let mut key = range.start;
                     while key < range.end {
-                        let img = match self.get(key, lsn).await {
+                        let img = match self.get(key, lsn, ctx).await {
                             Ok(img) => img,
                             Err(err) => {
                                 // If we fail to reconstruct a VM or FSM page, we can zero the
@@ -2554,7 +2691,11 @@ impl Timeline {
     /// Collect a bunch of Level 0 layer files, and compact and reshuffle them as
     /// as Level 1 files.
     ///
-    async fn compact_level0(&self, target_file_size: u64) -> anyhow::Result<()> {
+    async fn compact_level0(
+        &self,
+        target_file_size: u64,
+        ctx: &TimelineRequestContext,
+    ) -> anyhow::Result<()> {
         let CompactLevel0Phase1Result {
             new_layers,
             deltas_to_compact,
@@ -2570,10 +2711,7 @@ impl Timeline {
         // Do it here because we don't want to hold self.layers.write() while waiting.
         if let Some(remote_client) = &self.remote_client {
             debug!("waiting for upload ops to complete");
-            remote_client
-                .wait_completion()
-                .await
-                .context("wait for layer upload ops to complete")?;
+            remote_client.wait_completion(ctx).await?;
         }
 
         let mut layers = self.layers.write().unwrap();
@@ -2662,6 +2800,7 @@ impl Timeline {
         retain_lsns: Vec<Lsn>,
         cutoff_horizon: Lsn,
         pitr: Duration,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<()> {
         // First, calculate pitr_cutoff_timestamp and then convert it to LSN.
         //
@@ -2674,7 +2813,7 @@ impl Timeline {
             if let Some(pitr_cutoff_timestamp) = now.checked_sub(pitr) {
                 let pitr_timestamp = to_pg_timestamp(pitr_cutoff_timestamp);
 
-                match self.find_lsn_for_timestamp(pitr_timestamp).await? {
+                match self.find_lsn_for_timestamp(pitr_timestamp, ctx).await? {
                     LsnForTimestamp::Present(lsn) => lsn,
                     LsnForTimestamp::Future(lsn) => {
                         // The timestamp is in the future. That sounds impossible,
@@ -2724,7 +2863,7 @@ impl Timeline {
     /// within a layer file. We can only remove the whole file if it's fully
     /// obsolete.
     ///
-    pub(super) async fn gc(&self) -> anyhow::Result<GcResult> {
+    pub(super) async fn gc(&self, ctx: &TimelineRequestContext) -> anyhow::Result<GcResult> {
         fail_point!("before-timeline-gc");
 
         let _layer_removal_cs = self.layer_removal_cs.lock().await;
@@ -2745,7 +2884,7 @@ impl Timeline {
 
         let new_gc_cutoff = Lsn::min(horizon_cutoff, pitr_cutoff);
 
-        self.gc_timeline(horizon_cutoff, pitr_cutoff, retain_lsns, new_gc_cutoff)
+        self.gc_timeline(horizon_cutoff, pitr_cutoff, retain_lsns, new_gc_cutoff, ctx)
             .instrument(
                 info_span!("gc_timeline", timeline = %self.timeline_id, cutoff = %new_gc_cutoff),
             )
@@ -2758,6 +2897,7 @@ impl Timeline {
         pitr_cutoff: Lsn,
         retain_lsns: Vec<Lsn>,
         new_gc_cutoff: Lsn,
+        ctx: &TimelineRequestContext,
     ) -> anyhow::Result<GcResult> {
         let now = SystemTime::now();
         let mut result: GcResult = GcResult::default();
@@ -2796,10 +2936,7 @@ impl Timeline {
         // Do it here because we don't want to hold self.layers.write() while waiting.
         if let Some(remote_client) = &self.remote_client {
             debug!("waiting for upload ops to complete");
-            remote_client
-                .wait_completion()
-                .await
-                .context("wait for layer upload ops to complete")?;
+            remote_client.wait_completion(ctx).await?;
         }
 
         let mut layers_to_remove = Vec::new();
@@ -3058,9 +3195,6 @@ impl Timeline {
         let self_clone = self.myself.upgrade().expect("timeline is gone");
         task_mgr::spawn(
             &tokio::runtime::Handle::current(),
-            TaskKind::RemoteDownloadTask,
-            Some(self.tenant_id),
-            Some(self.timeline_id),
             &format!("download layer {}", remote_layer.short_id()),
             false,
             async move {
@@ -3106,8 +3240,6 @@ impl Timeline {
                 // XXX: This resets the exponential backoff because it's a new call to
                 // download_layer file.
                 drop(permit);
-
-                Ok(())
             },
         );
 
@@ -3116,6 +3248,7 @@ impl Timeline {
 
     pub async fn spawn_download_all_remote_layers(
         self: Arc<Self>,
+        ctx: &TimelineRequestContext,
     ) -> Result<DownloadRemoteLayersTaskInfo, DownloadRemoteLayersTaskInfo> {
         let mut status_guard = self.download_all_remote_layers_task_info.write().unwrap();
         if let Some(st) = &*status_guard {
@@ -3130,23 +3263,26 @@ impl Timeline {
             }
         }
 
+        let child_ctx = ctx.register_another(RequestContext::new(
+            TaskKind::DownloadAllRemoteLayers,
+            DownloadBehavior::Download,
+        ));
+        let task_id = child_ctx.context_id();
+
         let self_clone = Arc::clone(&self);
-        let task_id = task_mgr::spawn(
+        task_mgr::spawn(
             task_mgr::BACKGROUND_RUNTIME.handle(),
-            task_mgr::TaskKind::DownloadAllRemoteLayers,
-            Some(self.tenant_id),
-            Some(self.timeline_id),
             "download all remote layers task",
             false,
             async move {
-                self_clone.download_all_remote_layers().await;
+                self_clone.download_all_remote_layers(&child_ctx).await;
                 let mut status_guard = self_clone.download_all_remote_layers_task_info.write().unwrap();
                  match &mut *status_guard {
                     None => {
                         warn!("tasks status is supposed to be Some(), since we are running");
                     }
                     Some(st) => {
-                        let exp_task_id = format!("{}", task_mgr::current_task_id().unwrap());
+                        let exp_task_id = format!("{:?}", child_ctx.context_id());
                         if st.task_id != exp_task_id {
                             warn!("task id changed while we were still running, expecting {} but have {}", exp_task_id, st.task_id);
                         } else {
@@ -3154,13 +3290,12 @@ impl Timeline {
                         }
                     }
                 };
-                Ok(())
             }
             .instrument(info_span!(parent: None, "download_all_remote_layers", tenant = %self.tenant_id, timeline = %self.timeline_id))
         );
 
         let initial_info = DownloadRemoteLayersTaskInfo {
-            task_id: format!("{task_id}"),
+            task_id: format!("{task_id:?}"),
             state: DownloadRemoteLayersTaskState::Running,
             total_layer_count: 0,
             successful_download_count: 0,
@@ -3171,7 +3306,7 @@ impl Timeline {
         Ok(initial_info)
     }
 
-    async fn download_all_remote_layers(self: &Arc<Self>) {
+    async fn download_all_remote_layers(self: &Arc<Self>, ctx: &TimelineRequestContext) {
         let mut downloads: FuturesUnordered<_> = {
             let layers = self.layers.read().unwrap();
             layers
@@ -3187,13 +3322,7 @@ impl Timeline {
                 let st = st
                     .as_mut()
                     .expect("this function is only called after the task has been spawned");
-                assert_eq!(
-                    st.task_id,
-                    format!(
-                        "{}",
-                        task_mgr::current_task_id().expect("we run inside a task_mgr task")
-                    )
-                );
+                assert_eq!(st.task_id, format!("{:?}", ctx.context_id()));
                 let $st = st;
             };
         }
@@ -3217,9 +3346,9 @@ impl Timeline {
                         }
                     }
                 }
-                _ = task_mgr::shutdown_watcher() => {
+                _ = ctx.cancelled() => {
                     // Kind of pointless to watch for shutdowns here,
-                    // as download_remote_layer spawns other task_mgr tasks internally.
+                    // as download_remote_layer spawns other tasks internally.
                     lock_status!(st);
                     st.state = DownloadRemoteLayersTaskState::ShutDown;
                 }
@@ -3335,3 +3464,52 @@ fn rename_to_backup(path: &Path) -> anyhow::Result<()> {
 
     bail!("couldn't find an unused backup number for {:?}", path)
 }
+
+///
+/// TimelineRequestContext is a RequestContext that has a reference to a particular
+/// Timeline in a Tenant.
+///
+/// Like TenantRequestContext, holding a TimelineRequestContext prevents the Timeline
+/// from being deleted.
+///
+/// Use Timeline::get_context() to get a TimelineRequestContext.
+///
+pub struct TimelineRequestContext {
+    pub ctx: TenantRequestContext,
+    timeline: Arc<Timeline>,
+}
+
+impl Deref for TimelineRequestContext {
+    type Target = RequestContext;
+
+    fn deref(&self) -> &RequestContext {
+        &self.ctx.ctx
+    }
+}
+
+impl Drop for TimelineRequestContext {
+    fn drop(&mut self) {
+        self.timeline.deregister_context(self.context_id())
+    }
+}
+
+impl TimelineRequestContext {
+    pub fn register_another(&self, ctx: RequestContext) -> TimelineRequestContext {
+        let ctx = self.ctx.register_another(ctx);
+        if self
+            .timeline
+            .active_contexts
+            .lock()
+            .unwrap()
+            .insert(ctx.ctx.context_id(), ctx.ctx.task_kind())
+            .is_some()
+        {
+            panic!("active_contexts out of sync");
+        }
+
+        TimelineRequestContext {
+            ctx,
+            timeline: Arc::clone(&self.timeline),
+        }
+    }
+}

pageserver/src/tenant/upload_queue.rs

@@ -4,6 +4,7 @@ use super::storage_layer::LayerFileName;
 use crate::tenant::metadata::TimelineMetadata;
 use crate::tenant::remote_timeline_client::index::IndexPart;
 use crate::tenant::remote_timeline_client::index::LayerFileMetadata;
+use crate::tenant::TimelineRequestContext;
 use std::collections::{HashMap, VecDeque};
 use std::fmt::Debug;
 
@@ -73,6 +74,13 @@ pub(crate) struct UploadQueueInitialized {
     /// tasks to finish. For example, metadata upload cannot be performed before all
     /// preceding layer file uploads have completed.
     pub(crate) queued_operations: VecDeque<UploadOp>,
+
+    /// Context used for the upload tasks. Note that this is associated with the
+    /// Timeline, so this prevents the Timeline from being shut down. To ensure quick
+    /// shutdown, RemoteTimelineClient spawns a task to wait for cancellation on the
+    /// context and stop the queue. Otherwise we woudn't notice the cancellation
+    /// until next upload attempt.
+    pub(crate) upload_ctx: TimelineRequestContext,
 }
 
 pub(crate) struct UploadQueueStopped {
@@ -83,6 +91,7 @@ impl UploadQueue {
     pub(crate) fn initialize_empty_remote(
         &mut self,
         metadata: &TimelineMetadata,
+        upload_ctx: TimelineRequestContext,
     ) -> anyhow::Result<&mut UploadQueueInitialized> {
         match self {
             UploadQueue::Uninitialized => (),
@@ -108,6 +117,7 @@ impl UploadQueue {
             num_inprogress_deletions: 0,
             inprogress_tasks: HashMap::new(),
             queued_operations: VecDeque::new(),
+            upload_ctx,
         };
 
         *self = UploadQueue::Initialized(state);
@@ -117,6 +127,7 @@ impl UploadQueue {
     pub(crate) fn initialize_with_current_remote_index_part(
         &mut self,
         index_part: &IndexPart,
+        upload_ctx: TimelineRequestContext,
     ) -> anyhow::Result<&mut UploadQueueInitialized> {
         match self {
             UploadQueue::Uninitialized => (),
@@ -153,6 +164,7 @@ impl UploadQueue {
             num_inprogress_deletions: 0,
             inprogress_tasks: HashMap::new(),
             queued_operations: VecDeque::new(),
+            upload_ctx,
         };
 
         *self = UploadQueue::Initialized(state);

pageserver/src/walreceiver.rs

@@ -103,19 +103,18 @@ pub enum TaskStateUpdate<E> {
 impl<E: Clone> TaskHandle<E> {
     /// Initializes the task, starting it immediately after the creation.
     pub fn spawn<Fut>(
-        task: impl FnOnce(watch::Sender<TaskStateUpdate<E>>, CancellationToken) -> Fut + Send + 'static,
+        task: impl FnOnce(watch::Sender<TaskStateUpdate<E>>) -> Fut + Send + 'static,
+        cancellation: CancellationToken,
     ) -> Self
     where
         Fut: Future<Output = anyhow::Result<()>> + Send,
         E: Send + Sync + 'static,
     {
-        let cancellation = CancellationToken::new();
         let (events_sender, events_receiver) = watch::channel(TaskStateUpdate::Started);
 
-        let cancellation_clone = cancellation.clone();
         let join_handle = WALRECEIVER_RUNTIME.spawn(async move {
             events_sender.send(TaskStateUpdate::Started).ok();
-            task(events_sender, cancellation_clone).await
+            task(events_sender).await
         });
 
         TaskHandle {

pageserver/src/walreceiver/connection_manager.rs

@@ -11,9 +11,9 @@
 
 use std::{collections::HashMap, num::NonZeroU64, ops::ControlFlow, sync::Arc, time::Duration};
 
-use crate::task_mgr::TaskKind;
+use crate::context::{DownloadBehavior, RequestContext, TaskKind};
 use crate::task_mgr::WALRECEIVER_RUNTIME;
-use crate::tenant::Timeline;
+use crate::tenant::{Timeline, TimelineRequestContext};
 use crate::{task_mgr, walreceiver::TaskStateUpdate};
 use anyhow::Context;
 use chrono::{NaiveDateTime, Utc};
@@ -46,6 +46,7 @@ pub fn spawn_connection_manager_task(
     lagging_wal_timeout: Duration,
     max_lsn_wal_lag: NonZeroU64,
     auth_token: Option<Arc<String>>,
+    ctx: TimelineRequestContext,
 ) {
     let mut broker_client = get_broker_client().clone();
 
@@ -54,9 +55,6 @@ pub fn spawn_connection_manager_task(
 
     task_mgr::spawn(
         WALRECEIVER_RUNTIME.handle(),
-        TaskKind::WalReceiverManager,
-        Some(tenant_id),
-        Some(timeline_id),
         &format!("walreceiver for timeline {tenant_id}/{timeline_id}"),
         false,
         async move {
@@ -70,20 +68,21 @@ pub fn spawn_connection_manager_task(
             );
             loop {
                 select! {
-                    _ = task_mgr::shutdown_watcher() => {
+                    _ = ctx.cancelled() => {
                         info!("WAL receiver shutdown requested, shutting down");
                         walreceiver_state.shutdown().await;
-                        return Ok(());
+                        return;
                     },
                     loop_step_result = connection_manager_loop_step(
                         &mut broker_client,
                         &mut walreceiver_state,
+                        &ctx,
                     ) => match loop_step_result {
                         ControlFlow::Continue(()) => continue,
                         ControlFlow::Break(()) => {
                             info!("Connection manager loop ended, shutting down");
                             walreceiver_state.shutdown().await;
-                            return Ok(());
+                            return;
                         }
                     },
                 }
@@ -101,6 +100,7 @@ pub fn spawn_connection_manager_task(
 async fn connection_manager_loop_step(
     broker_client: &mut BrokerClientChannel,
     walreceiver_state: &mut WalreceiverState,
+    ctx: &TimelineRequestContext,
 ) -> ControlFlow<(), ()> {
     let mut timeline_state_updates = walreceiver_state.timeline.subscribe_for_state_updates();
 
@@ -226,6 +226,7 @@ async fn connection_manager_loop_step(
                 .change_connection(
                     new_candidate.safekeeper_id,
                     new_candidate.wal_source_connconf,
+                    ctx,
                 )
                 .await
         }
@@ -389,26 +390,38 @@ impl WalreceiverState {
         &mut self,
         new_sk_id: NodeId,
         new_wal_source_connconf: PgConnectionConfig,
+        ctx: &TimelineRequestContext,
     ) {
         self.drop_old_connection(true).await;
 
         let id = self.id;
         let connect_timeout = self.wal_connect_timeout;
         let timeline = Arc::clone(&self.timeline);
-        let connection_handle = TaskHandle::spawn(move |events_sender, cancellation| {
-            async move {
-                super::walreceiver_connection::handle_walreceiver_connection(
-                    timeline,
-                    new_wal_source_connconf,
-                    events_sender,
-                    cancellation,
-                    connect_timeout,
-                )
-                .await
-                .context("walreceiver connection handling failure")
-            }
-            .instrument(info_span!("walreceiver_connection", id = %id, node_id = %new_sk_id))
-        });
+
+        let child_ctx = ctx.register_another(RequestContext::with_parent(
+            TaskKind::WalReceiverConnection,
+            DownloadBehavior::Download,
+            ctx,
+        ));
+        let cancellation_token = child_ctx.cancellation_token().clone();
+
+        let connection_handle = TaskHandle::spawn(
+            move |events_sender| {
+                async move {
+                    super::walreceiver_connection::handle_walreceiver_connection(
+                        timeline,
+                        new_wal_source_connconf,
+                        events_sender,
+                        connect_timeout,
+                        child_ctx,
+                    )
+                    .await
+                    .context("walreceiver connection handling failure")
+                }
+                .instrument(info_span!("walreceiver_connection", id = %id, node_id = %new_sk_id))
+            },
+            cancellation_token,
+        );
 
         let now = Utc::now().naive_utc();
         self.wal_connection = Some(WalConnection {
@@ -820,6 +833,7 @@ fn wal_stream_connection_config(
 mod tests {
     use super::*;
     use crate::tenant::harness::{TenantHarness, TIMELINE_ID};
+    use tokio_util::sync::CancellationToken;
     use url::Host;
 
     fn dummy_broker_sk_timeline(
@@ -900,12 +914,15 @@ mod tests {
             started_at: now,
             sk_id: connected_sk_id,
             status: connection_status,
-            connection_task: TaskHandle::spawn(move |sender, _| async move {
-                sender
-                    .send(TaskStateUpdate::Progress(connection_status))
-                    .ok();
-                Ok(())
-            }),
+            connection_task: TaskHandle::spawn(
+                move |sender| async move {
+                    sender
+                        .send(TaskStateUpdate::Progress(connection_status))
+                        .ok();
+                    Ok(())
+                },
+                CancellationToken::new(),
+            ),
             discovered_new_wal: None,
         });
         state.wal_stream_candidates = HashMap::from([
@@ -1062,12 +1079,15 @@ mod tests {
             started_at: now,
             sk_id: connected_sk_id,
             status: connection_status,
-            connection_task: TaskHandle::spawn(move |sender, _| async move {
-                sender
-                    .send(TaskStateUpdate::Progress(connection_status))
-                    .ok();
-                Ok(())
-            }),
+            connection_task: TaskHandle::spawn(
+                move |sender| async move {
+                    sender
+                        .send(TaskStateUpdate::Progress(connection_status))
+                        .ok();
+                    Ok(())
+                },
+                CancellationToken::new(),
+            ),
             discovered_new_wal: None,
         });
         state.wal_stream_candidates = HashMap::from([
@@ -1127,12 +1147,15 @@ mod tests {
             started_at: now,
             sk_id: NodeId(1),
             status: connection_status,
-            connection_task: TaskHandle::spawn(move |sender, _| async move {
-                sender
-                    .send(TaskStateUpdate::Progress(connection_status))
-                    .ok();
-                Ok(())
-            }),
+            connection_task: TaskHandle::spawn(
+                move |sender| async move {
+                    sender
+                        .send(TaskStateUpdate::Progress(connection_status))
+                        .ok();
+                    Ok(())
+                },
+                CancellationToken::new(),
+            ),
             discovered_new_wal: None,
         });
         state.wal_stream_candidates = HashMap::from([(
@@ -1189,7 +1212,10 @@ mod tests {
             started_at: now,
             sk_id: NodeId(1),
             status: connection_status,
-            connection_task: TaskHandle::spawn(move |_, _| async move { Ok(()) }),
+            connection_task: TaskHandle::spawn(
+                move |_| async move { Ok(()) },
+                CancellationToken::new(),
+            ),
             discovered_new_wal: Some(NewCommittedWAL {
                 discovered_at: time_over_threshold,
                 lsn: new_lsn,
@@ -1233,18 +1259,18 @@ mod tests {
     const DUMMY_SAFEKEEPER_HOST: &str = "safekeeper_connstr";
 
     async fn dummy_state(harness: &TenantHarness<'_>) -> WalreceiverState {
+        let (tenant, tenant_ctx) = harness.load().await;
+        let (timeline, timeline_ctx) = tenant
+            .create_empty_timeline(TIMELINE_ID, Lsn(0), crate::DEFAULT_PG_VERSION, &tenant_ctx)
+            .expect("Failed to create an empty timeline for dummy wal connection manager");
+        let timeline = timeline.initialize(&timeline_ctx).unwrap();
+
         WalreceiverState {
             id: TenantTimelineId {
                 tenant_id: harness.tenant_id,
                 timeline_id: TIMELINE_ID,
             },
-            timeline: harness
-                .load()
-                .await
-                .create_empty_timeline(TIMELINE_ID, Lsn(0), crate::DEFAULT_PG_VERSION)
-                .expect("Failed to create an empty timeline for dummy wal connection manager")
-                .initialize()
-                .unwrap(),
+            timeline,
             wal_connect_timeout: Duration::from_secs(1),
             lagging_wal_timeout: Duration::from_secs(1),
             max_lsn_wal_lag: NonZeroU64::new(1024 * 1024).unwrap(),

pageserver/src/walreceiver/walreceiver_connection.rs

@@ -19,15 +19,13 @@ use postgres_protocol::message::backend::ReplicationMessage;
 use postgres_types::PgLsn;
 use tokio::{pin, select, sync::watch, time};
 use tokio_postgres::{replication::ReplicationStream, Client};
-use tokio_util::sync::CancellationToken;
 use tracing::{debug, error, info, trace, warn};
 
 use crate::{metrics::LIVE_CONNECTIONS_COUNT, walreceiver::TaskStateUpdate};
 use crate::{
     task_mgr,
-    task_mgr::TaskKind,
     task_mgr::WALRECEIVER_RUNTIME,
-    tenant::{Timeline, WalReceiverInfo},
+    tenant::{Timeline, TimelineRequestContext, WalReceiverInfo},
     walingest::WalIngest,
     walrecord::DecodedWALRecord,
 };
@@ -60,8 +58,8 @@ pub async fn handle_walreceiver_connection(
     timeline: Arc<Timeline>,
     wal_source_connconf: PgConnectionConfig,
     events_sender: watch::Sender<TaskStateUpdate<WalConnectionStatus>>,
-    cancellation: CancellationToken,
     connect_timeout: Duration,
+    ctx: TimelineRequestContext,
 ) -> anyhow::Result<()> {
     // Connect to the database in replication mode.
     info!("connecting to {wal_source_connconf:?}");
@@ -99,12 +97,9 @@ pub async fn handle_walreceiver_connection(
 
     // The connection object performs the actual communication with the database,
     // so spawn it off to run on its own.
-    let connection_cancellation = cancellation.clone();
+    let cancellation_token = ctx.cancellation_token().clone();
     task_mgr::spawn(
         WALRECEIVER_RUNTIME.handle(),
-        TaskKind::WalReceiverConnection,
-        Some(timeline.tenant_id),
-        Some(timeline.timeline_id),
         "walreceiver connection",
         false,
         async move {
@@ -118,9 +113,8 @@ pub async fn handle_walreceiver_connection(
                     }
                 },
 
-                _ = connection_cancellation.cancelled() => info!("Connection cancelled"),
+                _ = cancellation_token.cancelled() => info!("Connection cancelled"),
             }
-            Ok(())
         },
     );
 
@@ -180,7 +174,9 @@ pub async fn handle_walreceiver_connection(
 
     let mut waldecoder = WalStreamDecoder::new(startpoint, timeline.pg_version);
 
-    let mut walingest = WalIngest::new(timeline.as_ref(), startpoint).await?;
+    let mut walingest = WalIngest::new(timeline.as_ref(), startpoint, &ctx).await?;
+
+    let cancellation = ctx.cancellation_token().clone();
 
     while let Some(replication_message) = {
         select! {
@@ -251,7 +247,7 @@ pub async fn handle_walreceiver_connection(
                         ensure!(lsn.is_aligned());
 
                         walingest
-                            .ingest_record(recdata.clone(), lsn, &mut modification, &mut decoded)
+                            .ingest_record(recdata, lsn, &mut modification, &mut decoded, &ctx)
                             .await
                             .with_context(|| format!("could not ingest record at {lsn}"))?;
 
@@ -329,7 +325,7 @@ pub async fn handle_walreceiver_connection(
             // Send the replication feedback message.
             // Regular standby_status_update fields are put into this message.
             let (timeline_logical_size, _) = timeline
-                .get_current_logical_size()
+                .get_current_logical_size(&ctx)
                 .context("Status update creation failed to get current logical size")?;
             let status_update = ReplicationFeedback {
                 current_timeline_size: timeline_logical_size,

test_runner/fixtures/neon_fixtures.py

@@ -1914,9 +1914,9 @@ class NeonPageserver(PgProtocol):
             ".*Shutdown task error: walreceiver connection handling failure.*",
             ".*wal_connection_manager.*tcp connect error: Connection refused.*",
             ".*query handler for .* failed: Socket IO error: Connection reset by peer.*",
-            ".*serving compute connection task.*exited with error: Postgres connection error.*",
-            ".*serving compute connection task.*exited with error: Connection reset by peer.*",
-            ".*serving compute connection task.*exited with error: Postgres query error.*",
+            ".*connection handler exited with error: Postgres connection error.*",
+            ".*connection handler exited with error: Connection reset by peer.*",
+            ".*connection handler exited with error: Postgres query error.*",
             ".*Connection aborted: connection error: error communicating with the server: Broken pipe.*",
             ".*Connection aborted: connection error: error communicating with the server: Transport endpoint is not connected.*",
             ".*Connection aborted: connection error: error communicating with the server: Connection reset by peer.*",
@@ -1945,6 +1945,7 @@ class NeonPageserver(PgProtocol):
             # Tenant::delete_timeline() can cause any of the four following errors.
             # FIXME: we shouldn't be considering it an error: https://github.com/neondatabase/neon/issues/2946
             ".*could not flush frozen layer.*queue is in state Stopped",  # when schedule layer upload fails because queued got closed before compaction got killed
+            ".*Compaction failed, .* queue is in state Stopped.*",  # similarly for compaction
             ".*wait for layer upload ops to complete.*",  # .*Caused by:.*wait_completion aborted because upload queue was stopped
             ".*gc_loop.*Gc failed, retrying in.*timeline is Stopping",  # When gc checks timeline state after acquiring layer_removal_cs
             ".*compaction_loop.*Compaction failed, retrying in.*timeline is Stopping",  # When compaction checks timeline state after acquiring layer_removal_cs

test_runner/regress/test_ondemand_download.py

@@ -87,8 +87,22 @@ def test_ondemand_download_large_rel(
     # run checkpoint manually to be sure that data landed in remote storage
     client.timeline_checkpoint(tenant_id, timeline_id)
 
-    # wait until pageserver successfully uploaded a checkpoint to remote storage
+    # wait until pageserver successfully uploaded all the data, and the result
+    # of the compaction, to remote storage
     wait_for_upload(client, tenant_id, timeline_id, current_lsn)
+    def assert_queue_empty(file_kind, op_kind):
+        val = client.get_remote_timeline_client_metric(
+            "pageserver_remote_timeline_client_calls_unfinished",
+            tenant_id,
+            timeline_id,
+            file_kind,
+            op_kind,
+        )
+        assert val is not None, "expecting metric to be present"
+        assert int(val) == 0
+    wait_until(60, 0.5, lambda: assert_queue_empty(file_kind="layer", op_kind="upload"))
+    wait_until(60, 0.5, lambda: assert_queue_empty(file_kind="index", op_kind="upload"))
+    wait_until(60, 0.5, lambda: assert_queue_empty(file_kind="layer", op_kind="delete"))
     log.info("uploads have finished")
 
     ##### Stop the first pageserver instance, erase all its data
@@ -112,7 +126,7 @@ def test_ondemand_download_large_rel(
     # relation, so they are likely already downloaded. But the middle of the
     # table should not have been needed by anything yet.
     with pg.cursor() as cur:
-        assert query_scalar(cur, "select count(*) from tbl where id = 500000") == 1
+        assert query_scalar(cur, f"select count(*) from tbl where id = {num_rows}/2") == 1
 
     after_downloads = get_num_downloaded_layers(client, tenant_id, timeline_id)
     log.info(f"layers downloaded before {before_downloads} and after {after_downloads}")
@@ -371,7 +385,7 @@ def test_download_remote_layers_api(
     env.pageserver.allowed_errors.extend(
         [
             f".*download_all_remote_layers.*{tenant_id}.*{timeline_id}.*layer download failed.*remote-storage-download-pre-rename failpoint",
-            f".*initial size calculation.*{tenant_id}.*{timeline_id}.*Failed to calculate logical size",
+            f".*initial size calculation for {tenant_id}/{timeline_id} failed.*remote-storage-download-pre-rename failpoint",
         ]
     )
 

test_runner/regress/test_remote_storage.py

@@ -543,6 +543,7 @@ def test_timeline_deletion_with_files_stuck_in_upload_queue(
     )
 
     env = neon_env_builder.init_start()
+    env.pageserver.allowed_errors.append(".*request cancelled while waiting on uploads to finish.*")
 
     # create tenant with config that will determinstically allow
     # compaction and gc

test_runner/regress/test_tenant_detach.py

@@ -209,6 +209,7 @@ def test_tenant_reattach_while_busy(
     env.pageserver.allowed_errors.append(
         ".*Tenant .* will not become active\\. Current state: Stopping.*"
     )
+    env.pageserver.allowed_errors.append(".*Tenant .* is not active, state: Stopping.*")
 
     pageserver_http = env.pageserver.http_client()