| From: | Thomas Munro <thomas(dot)munro(at)gmail(dot)com> |
|---|---|
| To: | Simon Riggs <simon(at)2ndquadrant(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>, Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, Jakub Wartak <Jakub(dot)Wartak(at)tomtom(dot)com> |
| Subject: | Re: Background writer and checkpointer in crash recovery |
| Date: | 2020-11-12 04:26:39 |
| Message-ID: | CA+hUKG+1fCDXp5vnSQ0gvZSYNjxRNNbMJqA2QzZy2FO8CrhFkg@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Wed, Nov 11, 2020 at 9:57 PM Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> Having said that, we did raise the checkpoint_timeout by a lot, so the
> situation today might be quite different. A large checkpoint_timeout
> could eventually overflow shared buffers, with the right workload.
FWIW Jakuk Wartak did manage to show a 1.64x speedup while running
crash recovery of an insert-only workload (with a variant of this
patch that I shared in another thread), albeit with aggressive tuning:
> We don't have any stats to show whether this patch is worthwhile or
> not, so I suggest adding the attached instrumentation patch as well so
> we can see on production systems whether checkpoint_timeout is too
> high by comparison with pg_stat_bgwriter. The patch is written in the
> style of log_checkpoints.
Very useful. I've also been wondering how to get that sort of
information in hot standby.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Fujii Masao | 2020-11-12 04:36:07 | Re: Use standard SIGHUP and SIGTERM handlers in autoprewarm module |
| Previous Message | tsunakawa.takay@fujitsu.com | 2020-11-12 04:13:35 | RE: [Patch] Optimize dropping of relation buffers using dlist |