Horton

Re: Introduce XID age and inactive timeout based replication slot invalidation

Peter Smith <smithpb2250@gmail.com>

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From: Peter Smith <smithpb2250@gmail.com>
To: Nisha Moond <nisha.moond412@gmail.com>
Cc: Shlok Kyal <shlok.kyal.oss@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, vignesh C <vignesh21@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, shveta malik <shveta.malik@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Ajin Cherian <itsajin@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-01-21T02:55:39Z
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. Add a test for commit ac0e33136a using the injection point.

  2. Invalidate inactive replication slots.

  3. Fix incorrect slot type in BuildTupleHashTableExt

  4. Allow synced slots to have their inactive_since.

  5. Change last_inactive_time to inactive_since in pg_replication_slots.

  6. Track last_inactive_time in pg_replication_slots.

  7. Track invalidation_reason in pg_replication_slots.

  8. Add option force_initdb to PostgreSQL::Test::Cluster:init()

  9. Add a failover option to subscriptions.

  10. Allow setting failover property in the replication command.

  11. Allow to enable failover property for replication slots via SQL API.

  12. Track conflict_reason in pg_replication_slots.

  13. Log messages for replication slot acquisition and release.

  14. Remove vacuum_defer_cleanup_age

  15. Fix corruption due to vacuum_defer_cleanup_age underflowing 64bit xids

  16. meson: Add initial version of meson based build system

Some review comments for patch v61-0002

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src/backend/replication/slot.c

1.
  * Whether a slot needs to be invalidated depends on the cause. A slot is
- * removed if it:
+ * invalidated if it:
  * - RS_INVAL_WAL_REMOVED: requires a LSN older than the given segment
  * - RS_INVAL_HORIZON: requires a snapshot <= the given horizon in the given
  *   db; dboid may be InvalidOid for shared relations
  * - RS_INVAL_WAL_LEVEL: is logical
+ * - RS_INVAL_IDLE_TIMEOUT: idle slot timeout has occurred

1a.
Firstly the wording seems odd. "Is invalidated if it:" (missing words?)

~

1b.
Secondly, is this comment strictly correct? IIUC it's not *always*
going to be invalidated just because the cause is one of those listed.
e.g. the code calls InvalidatePossiblyObsoleteSlot but it might not
end up invalidating the slot having a cause RS_INVAL_IDLE_TIMEOUT.

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Kind Regards,
Peter Smith.
Fujitsu Australia