RE: Logical replication timeout problem - Mailing list pgsql-hackers

On Mon, Apr 18, 2022 at 00:35 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> On Mon, Apr 18, 2022 at 1:01 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > On Thu, Apr 14, 2022 at 5:50 PM Masahiko Sawada <sawada.mshk@gmail.com>
> wrote:
> > >
> > > On Wed, Apr 13, 2022 at 7:45 PM Amit Kapila <amit.kapila16@gmail.com>
> wrote:
> > > >
> > > > On Mon, Apr 11, 2022 at 12:09 PM wangw.fnst@fujitsu.com
> > > > <wangw.fnst@fujitsu.com> wrote:
> > > > >
> > > > > So I skip tracking lag during a transaction just like the current HEAD.
> > > > > Attach the new patch.
> > > > >
> > > >
> > > > Thanks, please find the updated patch where I have slightly
> > > > modified the comments.
> > > >
> > > > Sawada-San, Euler, do you have any opinion on this approach? I
> > > > personally still prefer the approach implemented in v10 [1]
> > > > especially due to the latest finding by Wang-San that we can't
> > > > update the lag-tracker apart from when it is invoked at the transaction end.
> > > > However, I am fine if we like this approach more.
> > >
> > > Thank you for updating the patch.
> > >
> > > The current patch looks much better than v10 which requires to call
> > > to
> > > update_progress() every path.
> > >
> > > Regarding v15 patch, I'm concerned a bit that the new function name,
> > > update_progress(), is too generic. How about
> > > update_replation_progress() or something more specific name?
> > >
> >
> > Do you intend to say update_replication_progress()? The word
> > 'replation' doesn't make sense to me. I am fine with this suggestion.
> 
> Yeah, that was a typo. I meant update_replication_progress().
Thanks for your comments.

> > > Regarding v15 patch, I'm concerned a bit that the new function name,
> > > update_progress(), is too generic. How about
> > > update_replation_progress() or something more specific name?
Improve as suggested. Change the name from update_progress to
update_replication_progress.

> > > ---
> > > +        if (end_xact)
> > > +        {
> > > +                /* Update progress tracking at xact end. */
> > > +                OutputPluginUpdateProgress(ctx, skipped_xact, end_xact);
> > > +                changes_count = 0;
> > > +                return;
> > > +        }
> > > +
> > > +        /*
> > > +         * After continuously processing CHANGES_THRESHOLD changes,
> > > we try to send
> > > +         * a keepalive message if required.
> > > +         *
> > > +         * We don't want to try sending a keepalive message after
> > > processing each
> > > +         * change as that can have overhead. Testing reveals that there is no
> > > +         * noticeable overhead in doing it after continuously
> > > processing 100 or so
> > > +         * changes.
> > > +         */
> > > +#define CHANGES_THRESHOLD 100
> > > +        if (++changes_count >= CHANGES_THRESHOLD)
> > > +        {
> > > +                OutputPluginUpdateProgress(ctx, skipped_xact, end_xact);
> > > +                changes_count = 0;
> > > +        }
> > > 
> > > Can we merge two if branches since we do the same things? Or did you
> > > separate them for better readability?
Improve as suggested. Merge two if-branches.

Attach the new patch.
1. Rename the new function(update_progress) to update_replication_progress. [suggestion by Sawada-San]
2. Merge two if-branches in new function update_replication_progress. [suggestion by Sawada-San.]
3. Improve comments to make them clear. [suggestions by Euler-San.]

Regards,
Wang wei