Re: Checkpoint cost, looks like it is WAL/CRC - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Checkpoint cost, looks like it is WAL/CRC
Date
Msg-id 9193.1121803617@sss.pgh.pa.us
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In response to Checkpoint cost, looks like it is WAL/CRC  (Josh Berkus <josh@agliodbs.com>)
Responses Re: Checkpoint cost, looks like it is WAL/CRC  (Josh Berkus <josh@agliodbs.com>)
List pgsql-hackers
Josh Berkus <josh@agliodbs.com> writes:
> So, now that we know what the performance bottleneck is, how do we fix it?

Josh, I see that all of those runs seem to be using wal_buffers = 8.
Have you tried materially increasing wal_buffers (say to 100 or 1000)
and/or experimenting with different wal_sync_method options since we
fixed the bufmgrlock problem?  I am wondering if the real issue is
WAL buffer contention or something like that.

It would also be useful to compare these runs to runs with fsync = off,
just to see how the performance changes.
        regards, tom lane


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