From c55de5e5123ce58ee19a47c08425949599285041 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 2 Jul 2018 22:19:46 +0900 Subject: [PATCH] Add wait event for fsync of WAL segments This has been visibly a forgotten spot in the first implementation of wait events for I/O added by 249cf07, and what has been missing is a fsync call for WAL segments which is a wrapper reacting on the value of GUC wal_sync_method. Reported-by: Konstantin Knizhnik Author: Konstantin Knizhnik Reviewed-by: Craig Ringer, Michael Paquier Discussion: https://postgr.es/m/4a243897-0ad8-f471-aa40-242591f2476e@postgrespro.ru --- doc/src/sgml/monitoring.sgml | 4 ++++ src/backend/access/transam/xlog.c | 2 ++ src/backend/postmaster/pgstat.c | 3 +++ src/include/pgstat.h | 1 + 4 files changed, 10 insertions(+) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index c2adb22dff..36d393d329 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1674,6 +1674,10 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser WALSenderTimelineHistoryRead Waiting for a read from a timeline history file during walsender timeline command. + + WALSync + Waiting for a WAL file to reach stable storage. + WALSyncMethodAssign Waiting for data to reach stable storage while assigning WAL sync method. diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index dcfef36591..0981657801 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -10156,6 +10156,7 @@ assign_xlog_sync_method(int new_sync_method, void *extra) void issue_xlog_fsync(int fd, XLogSegNo segno) { + pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC); switch (sync_method) { case SYNC_METHOD_FSYNC: @@ -10191,6 +10192,7 @@ issue_xlog_fsync(int fd, XLogSegNo segno) elog(PANIC, "unrecognized wal_sync_method: %d", sync_method); break; } + pgstat_report_wait_end(); } /* diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index 084573e77c..bbe73618c7 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -3925,6 +3925,9 @@ pgstat_get_wait_io(WaitEventIO w) case WAIT_EVENT_WAL_READ: event_name = "WALRead"; break; + case WAIT_EVENT_WAL_SYNC: + event_name = "WALSync"; + break; case WAIT_EVENT_WAL_SYNC_METHOD_ASSIGN: event_name = "WALSyncMethodAssign"; break; diff --git a/src/include/pgstat.h b/src/include/pgstat.h index be2f59239b..d59c24ae23 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -921,6 +921,7 @@ typedef enum WAIT_EVENT_WAL_INIT_SYNC, WAIT_EVENT_WAL_INIT_WRITE, WAIT_EVENT_WAL_READ, + WAIT_EVENT_WAL_SYNC, WAIT_EVENT_WAL_SYNC_METHOD_ASSIGN, WAIT_EVENT_WAL_WRITE } WaitEventIO; -- 2.49.0