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| author | Stephen Frost <sfrost@snowman.net> | 2021-03-24 13:07:51 -0400 |
|---|---|---|
| committer | Stephen Frost <sfrost@snowman.net> | 2021-03-24 13:07:51 -0400 |
| commit | bbcc4eb2e08fb6e4535c7f84b2c00f3ad508bb9b (patch) | |
| tree | 64b67f0b4ba21b9ac6496b6f3f21c1e456a77920 /src | |
| parent | e5595de03ec6ce60afde980ae05e9353a1501fdf (diff) | |
| download | postgresql-bbcc4eb2e08fb6e4535c7f84b2c00f3ad508bb9b.tar.gz postgresql-bbcc4eb2e08fb6e4535c7f84b2c00f3ad508bb9b.zip | |
Change checkpoint_completion_target default to 0.9
Common recommendations are that the checkpoint should be spread out as
much as possible, provided we avoid having it take too long. This
change updates the default to 0.9 (from 0.5) to match that
recommendation.
There was some debate about possibly removing the option entirely but it
seems there may be some corner-cases where having it set much lower to
try to force the checkpoint to be as fast as possible could result in
fewer periods of time of reduced performance due to kernel flushing.
General agreement is that the "spread more" is the preferred approach
though and those who need to tune away from that value are much less
common.
Reviewed-By: Michael Paquier, Peter Eisentraut, Tom Lane, David Steele,
Nathan Bossart
Discussion: https://postgr.es/m/20201207175329.GM16415%40tamriel.snowman.net
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/postmaster/checkpointer.c | 2 | ||||
| -rw-r--r-- | src/backend/utils/misc/guc.c | 2 | ||||
| -rw-r--r-- | src/backend/utils/misc/postgresql.conf.sample | 2 | ||||
| -rw-r--r-- | src/test/recovery/t/015_promotion_pages.pl | 1 |
4 files changed, 3 insertions, 4 deletions
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c index 5907a7befc5..e7e6a2a4594 100644 --- a/src/backend/postmaster/checkpointer.c +++ b/src/backend/postmaster/checkpointer.c @@ -145,7 +145,7 @@ static CheckpointerShmemStruct *CheckpointerShmem; */ int CheckPointTimeout = 300; int CheckPointWarning = 30; -double CheckPointCompletionTarget = 0.5; +double CheckPointCompletionTarget = 0.9; /* * Private state diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index cc0b9f6ad62..0c5dc4d3e84 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -3725,7 +3725,7 @@ static struct config_real ConfigureNamesReal[] = NULL }, &CheckPointCompletionTarget, - 0.5, 0.0, 1.0, + 0.9, 0.0, 1.0, NULL, NULL, NULL }, diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 74b416b74a8..b234a6bfe64 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -231,7 +231,7 @@ #checkpoint_timeout = 5min # range 30s-1d #max_wal_size = 1GB #min_wal_size = 80MB -#checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 - 1.0 +#checkpoint_completion_target = 0.9 # checkpoint target duration, 0.0 - 1.0 #checkpoint_flush_after = 0 # measured in pages, 0 disables #checkpoint_warning = 30s # 0 disables diff --git a/src/test/recovery/t/015_promotion_pages.pl b/src/test/recovery/t/015_promotion_pages.pl index 6fb70b5001b..25a9e4764a2 100644 --- a/src/test/recovery/t/015_promotion_pages.pl +++ b/src/test/recovery/t/015_promotion_pages.pl @@ -26,7 +26,6 @@ my $bravo = get_new_node('bravo'); $bravo->init_from_backup($alpha, 'bkp', has_streaming => 1); $bravo->append_conf('postgresql.conf', <<EOF); checkpoint_timeout=1h -checkpoint_completion_target=0.9 EOF $bravo->start; |