From 5202d2dc982e9861e2710e5ba099fe396f42c20f Mon Sep 17 00:00:00 2001
From: Christian Schwarz <christian@neon.tech>
Date: Mon, 24 Jun 2024 19:03:30 +0000
Subject: [PATCH] WIP: solution approach 1: propagate cancellationtoken from
 tenant

not enough, we need its gate, and there's no concept of child gate
---
 pageserver/src/tenant.rs  | 20 +++++++++++++-------
 pageserver/src/walredo.rs |  4 ++++
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/pageserver/src/tenant.rs b/pageserver/src/tenant.rs
index b13521e0ed..42d9e10307 100644
--- a/pageserver/src/tenant.rs
+++ b/pageserver/src/tenant.rs
@@ -658,11 +658,6 @@ impl Tenant {
             walredo_global_state,
         } = resources;
 
-        let wal_redo_manager = Arc::new(WalRedoManager::from(PostgresRedoManager::new(
-            walredo_global_state,
-            tenant_shard_id,
-        )));
-
         let attach_mode = attached_conf.location.attach_mode;
         let generation = attached_conf.location.generation;
 
@@ -2492,11 +2487,22 @@ impl Tenant {
         conf: &'static PageServerConf,
         attached_conf: AttachedTenantConf,
         shard_identity: ShardIdentity,
-        walredo_mgr: Option<Arc<WalRedoManager>>,
         tenant_shard_id: TenantShardId,
         remote_storage: GenericRemoteStorage,
         deletion_queue_client: DeletionQueueClient,
     ) -> Tenant {
+        let cancel = CancellationToken::default();
+
+        let walredo_mgr = if let TenantState::Broken { .. } = &state {
+            None
+        } else {
+            Some(Arc::new(WalRedoManager::from(PostgresRedoManager::new(
+                walredo_global_state,
+                tenant_shard_id,
+                cancel.child_token(),
+            ))))
+        };
+
         let (state, mut rx) = watch::channel(state);
 
         tokio::spawn(async move {
@@ -2571,7 +2577,7 @@ impl Tenant {
             cached_synthetic_tenant_size: Arc::new(AtomicU64::new(0)),
             eviction_task_tenant_state: tokio::sync::Mutex::new(EvictionTaskTenantState::default()),
             activate_now_sem: tokio::sync::Semaphore::new(0),
-            cancel: CancellationToken::default(),
+            cancel,
             gate: Gate::default(),
             timeline_get_throttle: Arc::new(throttle::Throttle::new(
                 Tenant::get_timeline_get_throttle_config(conf, &attached_conf.tenant_conf),
diff --git a/pageserver/src/walredo.rs b/pageserver/src/walredo.rs
index e9782e64b1..e3cb69bdc5 100644
--- a/pageserver/src/walredo.rs
+++ b/pageserver/src/walredo.rs
@@ -35,6 +35,7 @@ use anyhow::Context;
 use bytes::{Bytes, BytesMut};
 use pageserver_api::models::{WalRedoManagerProcessStatus, WalRedoManagerStatus};
 use pageserver_api::shard::TenantShardId;
+use tokio_util::sync::CancellationToken;
 use std::sync::Arc;
 use std::time::Duration;
 use std::time::Instant;
@@ -74,6 +75,7 @@ impl GlobalState {
 pub struct PostgresRedoManager {
     global_state: Arc<GlobalState>,
     tenant_shard_id: TenantShardId,
+    cancel: CancellationToken,
     last_redo_at: std::sync::Mutex<Option<Instant>>,
     /// The current [`process::WalRedoProcess`] that is used by new redo requests.
     /// We use [`heavier_once_cell`] for coalescing the spawning, but the redo
@@ -200,10 +202,12 @@ impl PostgresRedoManager {
     pub fn new(
         global_state: Arc<GlobalState>,
         tenant_shard_id: TenantShardId,
+        cancel: CancellationToken,
     ) -> PostgresRedoManager {
         // The actual process is launched lazily, on first request.
         PostgresRedoManager {
             global_state,
+            cancel,
             tenant_shard_id,
             last_redo_at: std::sync::Mutex::default(),
             redo_process: heavier_once_cell::OnceCell::default(),