On Sat, 2019-12-21 at 11:34 +0100, Marco Slot wrote: > The GUCs are not re-checked in the main loop in SyncRepWaitForLSN, so > backends will remain stuck there even if synchronous replication has > been (temporarily) disabled while they were waiting.
If you do: alter system set synchronous_standby_names=''; select pg_reload_conf(); it will release the backends waiting on sync rep. Regards, Jeff Davis