Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-29 Thread Bernd Helmle
--On 26. April 2014 19:42:47 -0700 Peter Geoghegan p...@heroku.com wrote: I suggest removing it for 9.5, and instead logging individual occurrences of backend fsync requests within ForwardFsyncRequest(). It seems fair to treat that as an anomaly to draw particular attention to. But wouldn't

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-29 Thread Peter Geoghegan
On Tue, Apr 29, 2014 at 2:51 AM, Bernd Helmle maili...@oopsware.de wrote: I suggest removing it for 9.5, and instead logging individual occurrences of backend fsync requests within ForwardFsyncRequest(). It seems fair to treat that as an anomaly to draw particular attention to. But wouldn't

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-29 Thread Robert Haas
On Tue, Apr 29, 2014 at 5:54 AM, Peter Geoghegan p...@heroku.com wrote: On Tue, Apr 29, 2014 at 2:51 AM, Bernd Helmle maili...@oopsware.de wrote: I suggest removing it for 9.5, and instead logging individual occurrences of backend fsync requests within ForwardFsyncRequest(). It seems fair to

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-29 Thread Tom Lane
Robert Haas robertmh...@gmail.com writes: Overall, I don't see much reason to tinker with this. If we had no reporting at all of this condition now, I'd probably be mildly more supportive of adding a log message than a counter. But since we've already got something and there's no real

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-29 Thread Jim Nasby
On 4/26/14, 9:42 PM, Peter Geoghegan wrote: Backend fsyncs are theoretically still possible after the fsync request queue compaction patch (which was subsequently back-patched to all supported release branches). However, I'm reasonably confident that that patch was so effective as to make a

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-29 Thread Peter Geoghegan
On Tue, Apr 29, 2014 at 12:02 PM, Jim Nasby j...@nasby.net wrote: All else equal, I don't like the idea of removing this from pg_stat_bgwriter. Being able to look there and see if this is occurring since last stats reset is much easier than grepping logfiles. Have you ever actually seen it at

[HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-26 Thread Peter Geoghegan
Backend fsyncs are theoretically still possible after the fsync request queue compaction patch (which was subsequently back-patched to all supported release branches). However, I'm reasonably confident that that patch was so effective as to make a backend fsync all but impossible. As such, it

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-26 Thread Tom Lane
Peter Geoghegan p...@heroku.com writes: Backend fsyncs are theoretically still possible after the fsync request queue compaction patch (which was subsequently back-patched to all supported release branches). However, I'm reasonably confident that that patch was so effective as to make a

Re: [HACKERS] Should pg_stat_bgwriter.buffers_backend_fsync be removed?

2014-04-26 Thread Peter Geoghegan
On Sat, Apr 26, 2014 at 9:16 PM, Tom Lane t...@sss.pgh.pa.us wrote: Peter Geoghegan p...@heroku.com writes: Backend fsyncs are theoretically still possible after the fsync request queue compaction patch (which was subsequently back-patched to all supported release branches). However, I'm