From 727589995a3e027046f0da7af6ba665b0b47f89f Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 18 Mar 2011 21:43:45 -0400 Subject: [PATCH] Move synchronous_standbys_defined updates from WAL writer to BG writer. This is advantageous because the BG writer is alive until much later in the shutdown sequence than WAL writer; we want to make sure that it's possible to shut off synchronous replication during a smart shutdown, else it might not be possible to complete the shutdown at all. Per very reasonable gripes from Fujii Masao and Simon Riggs. --- src/backend/postmaster/bgwriter.c | 8 ++++++++ src/backend/postmaster/walwriter.c | 6 ------ src/backend/replication/syncrep.c | 6 +++--- 3 files changed, 11 insertions(+), 9 deletions(-) diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c index 4df69c2f67..1b450a802b 100644 --- a/src/backend/postmaster/bgwriter.c +++ b/src/backend/postmaster/bgwriter.c @@ -55,6 +55,7 @@ #include "miscadmin.h" #include "pgstat.h" #include "postmaster/bgwriter.h" +#include "replication/syncrep.h" #include "storage/bufmgr.h" #include "storage/fd.h" #include "storage/ipc.h" @@ -363,6 +364,9 @@ BackgroundWriterMain(void) if (RecoveryInProgress()) ThisTimeLineID = GetRecoveryTargetTLI(); + /* Do this once before starting the loop, then just at SIGHUP time. */ + SyncRepUpdateSyncStandbysDefined(); + /* * Loop forever */ @@ -389,6 +393,8 @@ BackgroundWriterMain(void) { got_SIGHUP = false; ProcessConfigFile(PGC_SIGHUP); + /* update global shmem state for sync rep */ + SyncRepUpdateSyncStandbysDefined(); } if (checkpoint_requested) { @@ -704,6 +710,8 @@ CheckpointWriteDelay(int flags, double progress) { got_SIGHUP = false; ProcessConfigFile(PGC_SIGHUP); + /* update global shmem state for sync rep */ + SyncRepUpdateSyncStandbysDefined(); } AbsorbFsyncRequests(); diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c index e97ac63ed0..d0d7c9bebf 100644 --- a/src/backend/postmaster/walwriter.c +++ b/src/backend/postmaster/walwriter.c @@ -49,7 +49,6 @@ #include "libpq/pqsignal.h" #include "miscadmin.h" #include "postmaster/walwriter.h" -#include "replication/syncrep.h" #include "storage/bufmgr.h" #include "storage/fd.h" #include "storage/ipc.h" @@ -217,9 +216,6 @@ WalWriterMain(void) */ PG_SETMASK(&UnBlockSig); - /* Do this once before starting the loop, then just at SIGHUP time. */ - SyncRepUpdateSyncStandbysDefined(); - /* * Loop forever */ @@ -241,8 +237,6 @@ WalWriterMain(void) { got_SIGHUP = false; ProcessConfigFile(PGC_SIGHUP); - /* update global shmem state for sync rep */ - SyncRepUpdateSyncStandbysDefined(); } if (shutdown_requested) { diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index 8aef998b47..e99b43d8e0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -557,9 +557,9 @@ SyncRepWakeQueue(bool all) } /* - * WAL writer calls this as needed to update the shared sync_standbys_defined - * flag, so that backends don't remain permanently wedged if - * synchronous_standby_names is unset. It's safe to check the current value + * The background writer calls this as needed to update the shared + * sync_standbys_defined flag, so that backends don't remain permanently wedged + * if synchronous_standby_names is unset. It's safe to check the current value * without the lock, because it's only ever updated by one process. But we * must take the lock to change it. */ -- 2.40.0