Horton

Re: SLRU optimization - configurable buffer pool and partitioning the SLRU lock

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Ants Aasma <ants@cybertec.at>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-11-10T04:47:49Z
Lists: pgsql-hackers 
On Thu, Nov 9, 2023 at 4:55 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> IMO the whole area of SLRU buffering is in horrible shape and many users
> are struggling with overall PG performance because of it.  An
> improvement doesn't have to be perfect -- it just has to be much better
> than the current situation, which should be easy enough.  We can
> continue to improve later, using more scalable algorithms or ones that
> allow us to raise the limits higher.

I agree with this.

> The only point on which we do not have full consensus yet is the need to
> have one GUC per SLRU, and a lot of effort seems focused on trying to
> fix the problem without adding so many GUCs (for example, using shared
> buffers instead, or use a single "scaling" GUC).  I think that hinders
> progress.  Let's just add multiple GUCs, and users can leave most of
> them alone and only adjust the one with which they have a performance
> problems; it's not going to be the same one for everybody.

+1

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Fix zeroing of pg_serial page without SLRU bank lock

  2. Fix misspelled assertions

  3. GUC table: Add description to computed variables

  4. Improve performance of subsystems on top of SLRU

  5. Rename SLRU elements in view pg_stat_slru

  6. Use atomic access for SlruShared->latest_page_number

  7. Split use of SerialSLRULock, creating SerialControlLock

  8. Index SLRUs by 64-bit integers rather than by 32-bit integers

  9. Add a macro templatized hashtable.