On Thu, Mar 13, 2025 at 3:20 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
>
> On Thu, Mar 13, 2025 at 11:43 AM Dilip Kumar <dilipbal...@gmail.com> wrote:
> >
> > Looks fine, shall we add the missing publication point as well
> > something like below
> >
> > /*
> > * In operations like 'ALTER SUBSCRIPTION ... ADD/SET PUBLICATION' and
> > * 'CREATE SUBSCRIPTION', if the specified publication does not exist or
> > * if the replication origin is not updated before the worker exits,
> > * the WAL start location may point to a position prior to the publication's
> > * WAL record. This can cause persistent restarts and errors
> > * in the apply worker.
> > *
>
> I think that is too much related to pub-sub model, and ideally,
> pgoutput should not care about it. I have written a comment
> considering somebody using pgoutput decoding module via APIs.
I agree, here we just need to talk about skipping the missing
publication, not different scenarios where that can happen. This
comments look much better.
> > > * Additionally, dropping a subscription's publication should not
> > > * disrupt logical replication.
> > *
> > > * This ensures that a missing publication is skipped and loaded
> > > * when its corresponding WAL record is encountered.
> > */
> >
> >
> >
> > > ereport(WARNING,
> > > errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> > > errmsg("skipped loading publication: %s", pubname),
> > > errhint("If the publication is missing, create and refresh it.
> > > Otherwise, wait for the slot to reach the WAL record, then refresh"));
> > >
> > > > 2. + errhint("If the publication already exists, ignore it as it will
> > > > be loaded upon reaching the corresponding WAL record; otherwise,
> > > > create it."));
> > > >
> > > > Is this hint correct? This is a question rather than a comment: When
> > > > we reach a particular WAL where the publication was created, will the
> > > > publication automatically load, or does the user need to REFRESH the
> > > > publications?
> > >
> > > Users need to refresh the publication in case the relation is not
> > > already added to pg_subscription_rel and apply incremental changes.
> > > How about an error hint like:
> > > "If the publication is missing, create and refresh it. Otherwise, wait
> > > for the slot to reach the WAL record for the created publication, then
> > > refresh"
> >
>
> I have tried to split this information into errdetail and errhint in
> the attached. See and let me know what you think of the same.
Yes, the errhint also makes sense to me.
--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
