Re: Improve pg_sync_replication_slots() to wait for primary to advance

shveta malik <shveta.malik@gmail.com>

From: shveta malik <shveta.malik@gmail.com>

To: Ajin Cherian <itsajin@gmail.com>

Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Japin Li <japinli@hotmail.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>, shveta malik <shveta.malik@gmail.com>

Date: 2025-11-19T07:04:54Z

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 →

Enhance slot synchronization API to respect promotion signal.
- 4bed04d39566 17.10 landed
- 94efd308bcec 18.4 landed
- 1362bc33e025 19 (unreleased) landed
Fix inconsistent elevel in pg_sync_replication_slots() retry logic.
- f1ddaa15357f 19 (unreleased) landed
Refactor slot synchronization logic in slotsync.c.
- 788ec96d591d 19 (unreleased) landed
Fix intermittent BF failure in 040_standby_failover_slots_sync.
- b47c50e5667b 19 (unreleased) landed
Add retry logic to pg_sync_replication_slots().
- 0d2d4a0ec3ec 19 (unreleased) landed
Fix LOCK_TIMEOUT handling in slotsync worker.
- 04396eacd3fa 19 (unreleased) cited
Add slotsync skip statistics.
- 76b78721ca49 19 (unreleased) cited

On Wed, Nov 12, 2025 at 1:54 PM Ajin Cherian <itsajin@gmail.com> wrote:
>
>
> Attaching patch v23 addressing these comments.
>

Thanks for the patch.

I observed that if the API is taking a nap in between slot sync cycles
and a promotion is triggered during that time, the promotion has to
wait for the entire nap period to finish before slot-sync stops and
the process can continue. There should be a mechanism to wake up the
backend so the API can exit early once stopSignaled is set. How about
doing SetLatch for the process doing synchronization in
ShutDownSlotSync()?

thanks
Shveta