Shut down the DNS threadpool (#11190)

The DNS threadpool must be explicitly stopped, otherwise Synapse will hang indefinitely when asked to shut down.
matrix-org · Oct 27, 2021 · f3a4be8 · f3a4be8
1 parent 72626b7
commit f3a4be8
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 0 deletions.
diff --git a/changelog.d/11190.bugfix b/changelog.d/11190.bugfix
@@ -0,0 +1 @@
+Fix a performance regression introduced in 1.44.0 which could cause client requests to time out when making large numbers of outbound requests.
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
@@ -346,6 +346,7 @@ async def start(hs: "HomeServer"):
     # numbers of DNS requests don't starve out other users of the threadpool.
     resolver_threadpool = ThreadPool(name="gai_resolver")
     resolver_threadpool.start()
+    reactor.addSystemEventTrigger("during", "shutdown", resolver_threadpool.stop)
     reactor.installNameResolver(
         GAIResolver(reactor, getThreadPool=lambda: resolver_threadpool)
     )