Horton

Re: long-standing data loss bug in initial sync of logical replication

vignesh C <vignesh21@gmail.com>

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From: vignesh C <vignesh21@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-07-10T16:37:29Z
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. Fix typo in test file name added in commit 4909b38af0.

  2. Fix data loss in logical replication.

  3. Avoid invalidating all RelationSyncCache entries on publication rename.

  4. Remove obsolete RECHECK keyword completely

  5. Backport BackgroundPsql perl test module

Attachments

On Wed, 10 Jul 2024 at 12:28, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Tue, Jul 9, 2024 at 8:14 PM vignesh C <vignesh21@gmail.com> wrote:
> >
> > On Tue, 9 Jul 2024 at 17:05, Amit Kapila <amit.kapila16@gmail.com> wrote:
> > >
> > > On Mon, Jul 1, 2024 at 10:51 AM vignesh C <vignesh21@gmail.com> wrote:
> > > >
> > > >
> > > > This issue is present in all supported versions. I was able to
> > > > reproduce it using the steps recommended by Andres and Tomas's
> > > > scripts. I also conducted a small test through TAP tests to verify the
> > > > problem. Attached is the alternate_lock_HEAD.patch, which includes the
> > > > lock modification(Tomas's change) and the TAP test.
> > > >
> > >
> > > @@ -1568,7 +1568,7 @@ OpenTableList(List *tables)
> > >   /* Allow query cancel in case this takes a long time */
> > >   CHECK_FOR_INTERRUPTS();
> > >
> > > - rel = table_openrv(t->relation, ShareUpdateExclusiveLock);
> > > + rel = table_openrv(t->relation, ShareRowExclusiveLock);
> > >
> > > The comment just above this code ("Open, share-lock, and check all the
> > > explicitly-specified relations") needs modification. It would be
> > > better to explain the reason of why we would need SRE lock here.
> >
> > Updated comments for the same.
> >
>
> The patch missed to use the ShareRowExclusiveLock for partitions, see
> attached. I haven't tested it but they should also face the same
> problem. Apart from that, I have changed the comments in a few places
> in the patch.

I could not hit the updated ShareRowExclusiveLock changes through the
partition table, instead I could verify it using the inheritance
table. Added a test for the same and also attaching the backbranch
patch.

Regards,
Vignesh