Horton

Re: How can end users know the cause of LR slot sync delays?

Michael Banck <mbanck@gmx.net>

View thread
From: Michael Banck <mbanck@gmx.net>
To: shveta malik <shveta.malik@gmail.com>
Cc: Shlok Kyal <shlok.kyal.oss@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Ashutosh Sharma <ashu.coek88@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>
Date: 2025-11-28T09:15:52Z
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. Rename column slotsync_skip_at to slotsync_last_skip.

  2. Add slotsync_skip_reason column to pg_replication_slots view.

  3. Fix test failure caused by commit 76b78721ca.

  4. Fix a BF failure caused by commit 76b78721ca.

  5. Add slotsync skip statistics.

Hi,

On Fri, Nov 21, 2025 at 11:00:36AM +0530, shveta malik wrote:
> 2)
> +            s.slotsync_skip_count,
> +            s.last_slotsync_skip_at,
> 
> Shall we rename last_slotsync_skip_at to slotsync_last_skip_at. That
> way all slotsync related stats columns will have same prefix.

I am not sure that was a great change. AFAICT, we only have _at once in
the catalog, and that if for two_phase_at. There, AIUI, it marks the
specific timestamp two_phase was enabled(?) for logical replication, not
the last time something happened.

So I think using _at here as well is confusing as this one is about the
last time a slotsync was skipped. I think it should be renamed to
'last', as per our usual naming.

I agree that having the same prefix would be nice, but it looks like
almost all other columns are named last_something (except for
checksum_last_failure, but that's been around for a long time).

So I suggest to reopen the discussion about naming this (second) column.


Michael