Re: [BUG] Logical replication failure "ERROR: could not map filenode "base/13237/442428" to relation OID" with catalog modifying txns

On Tue, Jul 12, 2022 at 2:53 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> On Tue, Jul 12, 2022 at 5:58 PM shiy(dot)fnst(at)fujitsu(dot)com
> <shiy(dot)fnst(at)fujitsu(dot)com> wrote:
> >
> >
> > It happened when executing the following code because it tried to free a NULL
> > pointer (catchange_xip).
> >
> > /* be tidy */
> > if (ondisk)
> > pfree(ondisk);
> > + if (catchange_xip)
> > + pfree(catchange_xip);
> > }
> >
> > It seems to be related to configure option. I could reproduce it when using
> > `./configure --enable-debug`.
> > But I couldn't reproduce with `./configure --enable-debug CFLAGS="-Og -ggdb"`.
>
> Hmm, I could not reproduce this problem even if I use ./configure
> --enable-debug. And it's weird that we checked if catchange_xip is not
> null but we did pfree for it:
>

Yeah, this looks weird to me as well but one difference in running
tests could be the timing of WAL LOG for XLOG_RUNNING_XACTS. That may
change the timing of SnapBuildSerialize. The other thing we can try is
by checking the value of catchange_xcnt before pfree.

BTW, I think ReorderBufferGetCatalogChangesXacts should have an Assert
to ensure rb->catchange_ntxns and xcnt are equal. We can probably then
avoid having xcnt_p as an out parameter as the caller can use
rb->catchange_ntxns instead.

--
With Regards,
Amit Kapila.