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: Shlok Kyal <shlok.kyal.oss@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, shveta malik <shveta.malik@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Ashutosh Sharma <ashu.coek88@gmail.com>
Date: 2025-12-04T12:29:43Z
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 Thu, Dec 04, 2025 at 12:06:44PM +0530, Shlok Kyal wrote:
> On Thu, 4 Dec 2025 at 08:54, Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > On Wed, Dec 3, 2025 at 10:59 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > > On Fri, Nov 28, 2025 at 3:37 PM Michael Banck <mbanck@gmx.net> wrote:
> > > > On Fri, Nov 28, 2025 at 03:30:48PM +0530, Amit Kapila wrote:
> > > > > I suggested the current one because having the last was making the
> > > > > column name bit longer, and anyway the description clarifies it, but I
> > > > > see your point. So, the other options could be
> > > > > slotsync_last_skip_time, sync_last_skip_time, last_slotsync_skip_time,
> > > > > last_sync_skip_time .
> > > >
> > > > I also noticed while going through src/backend/catalog/system_views.sql
> > > > that *_last_*_time is rare, so in terms of brevity, removing the _time
> > > > at the end would be ok. "last_" already conveys time/a timestamp.
> > > >
> > >
> > > I think it depends on case to case but having last in the similar
> > > cases seems to be a common practice. So, again thinking about it based
> > > on your suggestion and looking at existing fields, I suggest we should
> > > rename slotsync_skip_at to slotsync_last_skip. This is similar to
> > > checksum_last_failure. I think there is a value in keeping initials
> > > the same for similar fields in the view as users could easily identify
> > > the related columns while querying the view. For example,
> > > checksum_failures and checksum_last_failure in pg_stat_database.
> > >
> > > Anyone else have any opinion on the names proposed here?
> >
> > IMHO keeping it 'slotsync_last_skip' makes more sense, so that we can
> > keep the *slotsync* prefix and the naming style also match with some
> > other usage e.g. 'checksum_last_failure' as well.  I see there are
> > more common examples where the name starts with 'last_' but I prefer
> > the 'slotsync_last_skip' name.
> 
> I also agree with Amit and Dilip. I have made the change and attached
> the patch for the same.

LGTM.


Michael