From f5ca897292d78faf6a447a8f4542b1b1400e6dd1 Mon Sep 17 00:00:00 2001
From: Joonas Koivunen <joonas@neon.tech>
Date: Thu, 23 Mar 2023 12:00:52 +0200
Subject: [PATCH] fix: less logging at shutdown (#3866)

Log less during shutdown; don't log anything for quickly (less than 1s)
exiting tasks.
---
 pageserver/src/task_mgr.rs | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/pageserver/src/task_mgr.rs b/pageserver/src/task_mgr.rs
index 2734031a09..44b1bbb06d 100644
--- a/pageserver/src/task_mgr.rs
+++ b/pageserver/src/task_mgr.rs
@@ -481,13 +481,25 @@ pub async fn shutdown_tasks(
     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
+            task_mut.join_handle.take()
         };
-        if let Some(join_handle) = join_handle {
-            let _ = join_handle.await;
+        if let Some(mut join_handle) = join_handle {
+            let completed = tokio::select! {
+                _ = &mut join_handle => { true },
+                _ = tokio::time::sleep(std::time::Duration::from_secs(1)) => {
+                    // allow some time to elapse before logging to cut down the number of log
+                    // lines.
+                    info!("waiting for {} to shut down", task.name);
+                    false
+                }
+            };
+            if !completed {
+                // we never handled this return value, but:
+                // - we don't deschedule which would lead to is_cancelled
+                // - panics are already logged (is_panicked)
+                // - task errors are already logged in the wrapper
+                let _ = join_handle.await;
+            }
         } else {
             // Possibly one of:
             //  * The task had not even fully started yet.