Re: POC: make mxidoff 64 bits

Maxim Orlov <orlovmg@gmail.com>

From: Maxim Orlov <orlovmg@gmail.com>
To: wenhui qiu <qiuwenhuifx@gmail.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Alexander Korotkov <aekorotkov@gmail.com>, Postgres hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-11-08T18:10:28Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix partial read handling in pg_upgrade's multixact conversion

  2. Increase timeout in multixid_conversion upgrade test

  3. Improve sanity checks on multixid members length

  4. Clarify comment on multixid offset wraparound check

  5. Never store 0 as the nextMXact

  6. Add runtime checks for bogus multixact offsets

  7. Widen MultiXactOffset to 64 bits

  8. Move pg_multixact SLRU page format definitions to a separate header

  9. Convert confusing macros in multixact.c to static inline functions

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

  11. Cope with possible failure of the oldest MultiXact to exist.

Attachments

On Fri, 25 Oct 2024 at 06:39, wenhui qiu <qiuwenhuifx@gmail.com> wrote:

>
> + * Multixact members warning threshold.
> + *
> + * If difference bettween nextOffset and oldestOffset exceed this value,
> we
> + * trigger autovacuum in order to release the disk space if possible.
> + */
> +#define MULTIXACT_MEMBER_AUTOVAC_THRESHOLD UINT64CONST(0xFFFFFFFF)
> Can we refine this annotation a bit? for example
>
Thank you, fixed.

Sorry for a late reply. There was a problem in upgrade with offset
wraparound. Here is a fixed version. Test also added. I decide to use my
old patch to set a non-standard multixacts for the old cluster, fill it
with data and do pg_upgrade.

Here is how to test. All the patches are for 14e87ffa5c543b5f3 master
branch.
1) Get the 14e87ffa5c543b5f3 master branch apply patches
0001-Add-initdb-option-to-initialize-cluster-with-non-sta.patch and
0002-TEST-lower-SLRU_PAGES_PER_SEGMENT.patch
2) Get the 14e87ffa5c543b5f3 master branch in a separate directory and
apply v6 patch set.
3) Build two branches.
4) Use ENV oldinstall to run the test: PROVE_TESTS=t/005_mxidoff.pl
oldinstall=/home/orlov/proj/pgsql-new PG_TEST_NOCLEAN=1 make check -C
src/bin/pg_upgrade/

Maybe, I'll make a shell script to automate this steps if required.

-- 
Best regards,
Maxim Orlov.