Re: trying again to get incremental backup

On Thu, Dec 7, 2023 at 4:15 PM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

Hi Robert,

> On Thu, Dec 7, 2023 at 9:42 AM Jakub Wartak
> <jakub(dot)wartak(at)enterprisedb(dot)com> wrote:
> > Comment: I was wondering if it wouldn't make some sense to teach
> > pg_resetwal to actually delete all WAL summaries after any any
> > WAL/controlfile alteration?
>
> I thought that this was a good idea so I decided to go implement it,
> only to discover that it was already part of the patch set ... did you
> find some case where it doesn't work as expected? The code looks like
> this:

Ah, my bad, with a fresh mind and coffee the error message makes it
clear and of course it did reset the summaries properly.

While we are at it, maybe around the below in PrepareForIncrementalBackup()

if (tlep[i] == NULL)
ereport(ERROR,

(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("timeline %u found in
manifest, but not in this server's history",
range->tli)));

we could add

errhint("You might need to start a new full backup instead of
incremental one")

?

> > test_pending_2pc.sh - getting GOOD on most recent runs, but several
> > times during early testing (probably due to my own mishaps), I've been
> > hit by Abort/TRAP. I'm still investigating and trying to reproduce
> > those ones. TRAP: failed Assert("summary_end_lsn >=
> > WalSummarizerCtl->pending_lsn"), File: "walsummarizer.c", Line: 940
>
> I have a fix for this locally, but I'm going to hold off on publishing
> a new version until either there's a few more things I can address all
> at once, or until Thomas commits the ubsan fix.
>

Great, I cannot get it to fail again today, it had to be some dirty
state of the testing env. BTW: Thomas has pushed that ubsan fix.

-J.