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| author | Simon Riggs <simon@2ndQuadrant.com> | 2012-06-07 19:22:47 +0100 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2012-06-07 19:22:47 +0100 |
| commit | 2c8a4e9be2730342cbca85150a2a9d876aa77ff6 (patch) | |
| tree | d4431bf22e39c7c2a145cb2ce838f2cad6e0d3f8 | |
| parent | b50991eedb458a81d875d049f48fb62ab1685c0d (diff) | |
| download | postgresql-2c8a4e9be2730342cbca85150a2a9d876aa77ff6.tar.gz postgresql-2c8a4e9be2730342cbca85150a2a9d876aa77ff6.zip | |
Wake WALSender to reduce data loss at failover for async commit.
WALSender now woken up after each background flush by WALwriter, avoiding
multi-second replication delay for an all-async commit workload.
Replication delay reduced from 7s with default settings to 200ms and often
much less, allowing significantly reduced data loss at failover.
Andres Freund and Simon Riggs
| -rw-r--r-- | src/backend/access/transam/xlog.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index d3650bdf051..0f2678cfda0 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -2271,6 +2271,13 @@ XLogBackgroundFlush(void) END_CRIT_SECTION(); + /* + * If we wrote something then we have something to send to standbys also, + * otherwise the replication delay become around 7s with just async commit. + */ + if (wrote_something) + WalSndWakeup(); + return wrote_something; } |