Horton

Re: MultiXact\SLRU buffers configuration

x4mmm@yandex-team.ru

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From: Andrey Borodin <x4mmm@yandex-team.ru>
To: vignesh C <vignesh21@gmail.com>
Cc: Andrew Borodin <amborodin86@gmail.com>, i.lazarev@postgrespro.ru, Yura Sokolov <y.sokolov@postgrespro.ru>, Andres Freund <andres@anarazel.de>, Thomas Munro <thomas.munro@gmail.com>, Gilles Darold <gilles@darold.net>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Alexander Korotkov <aekorotkov@gmail.com>, Anastasia Lubennikova <a.lubennikova@postgrespro.ru>, Daniel Gustafsson <daniel@yesql.se>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, pgsql-hackers mailing list <pgsql-hackers@postgresql.org>
Date: 2024-01-27T04:58:18Z
Lists: pgsql-hackers 

> On 20 Jan 2024, at 08:31, vignesh C <vignesh21@gmail.com> wrote:
> 
> On Mon, 9 Jan 2023 at 09:49, Andrey Borodin <amborodin86@gmail.com> wrote:
>> 
>> On Tue, Jan 3, 2023 at 5:02 AM vignesh C <vignesh21@gmail.com> wrote:
>>> does not apply on top of HEAD as in [1], please post a rebased patch:
>>> 
>> Thanks! Here's the rebase.
> 
> I'm seeing that there has been no activity in this thread for more
> than 1 year now, I'm planning to close this in the current commitfest
> unless someone is planning to take it forward.

Hi Vignesh,

thanks for the ping! Most important parts of this patch set are discussed in [0]. If that patchset will be committed, I'll withdraw entry for this thread from commitfest.
There's a version of Multixact-specific optimizations [1], but I hope they will not be necessary with effective caches developed in [0]. It seems to me that most important part of those optimization is removing sleeps under SLRU lock on standby [2] by Kyotaro Horiguchi. But given that cache optimizations took 4 years to get closer to commit, I'm not sure we will get this optimization any time soon...

Thanks!

Best regards, Andrey Borodin.


[0] https://www.postgresql.org/message-id/flat/CAFiTN-vzDvNz%3DExGXz6gdyjtzGixKSqs0mKHMmaQ8sOSEFZ33A%40mail.gmail.com
[1] https://www.postgresql.org/message-id/flat/2ECE132B-C042-4489-930E-DBC5D0DAB84A%40yandex-team.ru#5f7e7022647be9eeecfc2ae75d765500
[2] https://www.postgresql.org/message-id/flat/20200515.090333.24867479329066911.horikyota.ntt%40gmail.com#855f8bb7205890579a363d2344b4484d

Commits

  1. Rework new SLRU test with injection points

  2. injection_point: Add injection_points.stats

  3. injection_points: Add initialization of shmem state when loading module

  4. Add injection-point test for new multixact CV usage

  5. Use conditional variable to wait for next MultiXact offset

  6. Improve performance of subsystems on top of SLRU

  7. Adjust VACUUM hastup LP_REDIRECT comments.

  8. Test replay of regression tests, attempt II.