Re: Excessive PostmasterIsAlive calls slow down WAL redo
Stephen Frost <sfrost@snowman.net>
From: Stephen Frost <sfrost@snowman.net>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-04-06T19:09:52Z
Lists: pgsql-hackers
Greetings, * Heikki Linnakangas (hlinnaka@iki.fi) wrote: > On 06/04/18 19:39, Andres Freund wrote: > >On 2018-04-06 07:39:28 -0400, Stephen Frost wrote: > >>While I tend to agree that it'd be nice to just make it cheaper, that > >>doesn't seem like something that we'd be likely to back-patch and I tend > >>to share Heikki's feelings that this is a performance regression we > >>should be considering fixing in released versions. > > To be clear, this isn't a performance *regression*. It's always been bad. Oh, I see, apologies for the confusion, my initial read was that this was due to some patch that had gone in previously, hence it was an actual regression. I suppose I tend to view performance issues as either "regression" or "opportunity for improvement" and when you said "bug" it made me think it was a regression. :) > I'm not sure if I'd backpatch this. Maybe after it's been in 'master' for a > while and we've gotten some field testing of it. If it's not a regression then there's I definitely think the bar is much higher to consider this something to back-patch. I wouldn't typically argue for back-patching a performance improvement unless it's to address a specific regression. Thanks! Stephen
Commits
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Poll postmaster less frequently in recovery.
- 57dcc2ef3320 14.0 landed
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Use signals for postmaster death on FreeBSD.
- f98b8476cd4a 12.0 landed
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Use signals for postmaster death on Linux.
- 9f09529952ac 12.0 landed
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Introduce a pipe between postmaster and each backend, which can be used to
- 89fd72cbf26f 9.2.0 cited