Thread: Make use of assign_checkpoint_completion_target() to calculate CheckPointSegments correctly
Make use of assign_checkpoint_completion_target() to calculate CheckPointSegments correctly
From
Bharath Rupireddy
Date:
Hi,
It looks like assign_checkpoint_completion_target() is defined [1],
but never used, because of which CheckPointSegments may miss to
account for changed checkpoint_completion_target. I'm attaching a tiny
patch to fix this.
Thoughts?
[1]
commit 88e982302684246e8af785e78a467ac37c76dee9
Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon Feb 23 18:53:02 2015 +0200
Replace checkpoint_segments with min_wal_size and max_wal_size.
--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
Attachment
Re: Make use of assign_checkpoint_completion_target() to calculate CheckPointSegments correctly
From
Michael Paquier
Date:
On Mon, Dec 26, 2022 at 06:12:34PM +0530, Bharath Rupireddy wrote: > It looks like assign_checkpoint_completion_target() is defined [1], > but never used, because of which CheckPointSegments may miss to > account for changed checkpoint_completion_target. I'm attaching a tiny > patch to fix this. > > Thoughts? Oops. It looks like you are right here. This would impact the calculation of CheckPointSegments on reload when checkpoint_completion_target is updated. This is wrong since we've switched to max_wal_size as of 88e9823, so this had better be backpatched all the way down. Thoughts? -- Michael
Attachment
Re: Make use of assign_checkpoint_completion_target() to calculate CheckPointSegments correctly
From
Bharath Rupireddy
Date:
On Tue, Jan 17, 2023 at 12:31 PM Michael Paquier <michael@paquier.xyz> wrote: > > On Mon, Dec 26, 2022 at 06:12:34PM +0530, Bharath Rupireddy wrote: > > It looks like assign_checkpoint_completion_target() is defined [1], > > but never used, because of which CheckPointSegments may miss to > > account for changed checkpoint_completion_target. I'm attaching a tiny > > patch to fix this. > > > > Thoughts? > > Oops. It looks like you are right here. This would impact the > calculation of CheckPointSegments on reload when > checkpoint_completion_target is updated. This is wrong since we've > switched to max_wal_size as of 88e9823, so this had better be > backpatched all the way down. > > Thoughts? +1 to backpatch as setting checkpoint_completion_target will not take effect immediately. -- Bharath Rupireddy PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
Re: Make use of assign_checkpoint_completion_target() to calculate CheckPointSegments correctly
From
Michael Paquier
Date:
On Tue, Jan 17, 2023 at 07:55:53PM +0530, Bharath Rupireddy wrote: > On Tue, Jan 17, 2023 at 12:31 PM Michael Paquier <michael@paquier.xyz> wrote: >> Oops. It looks like you are right here. This would impact the >> calculation of CheckPointSegments on reload when >> checkpoint_completion_target is updated. This is wrong since we've >> switched to max_wal_size as of 88e9823, so this had better be >> backpatched all the way down. >> >> Thoughts? > > +1 to backpatch as setting checkpoint_completion_target will not take > effect immediately. Okay, applied down to 11. I have double-checked the surroundings to see if there was a similar mistake or something hiding around CheckpointSegments but noticed nothing (also did some primary/standby pgbench-ing with periodic reloads of checkpoint_completion_target, while on it). -- Michael