On Thu, Jul 25, 2024 at 6:52 PM Andrew Dunstan <and...@dunslane.net> wrote: > > > On 2024-07-25 Th 3:40 PM, Masahiko Sawada wrote: > > On Thu, Jul 25, 2024 at 11:06 AM Masahiko Sawada <sawada.m...@gmail.com> > wrote: > > On Thu, Jul 25, 2024 at 10:56 AM Andrew Dunstan <and...@dunslane.net> wrote: > > On 2024-07-23 Tu 6:59 PM, Masahiko Sawada wrote: > > See > <https://bitbucket.org/adunstan/rotfang-fdw/downloads/xid-wraparound-result.tar.bz2> > > > The failure logs are from a run where both tests 1 and 2 failed. > > Thank you for sharing the logs. > > I think that the problem seems to match what Alexander Lakhin > mentioned[1]. Probably we can fix such a race condition somehow but > I'm not sure it's worth it as setting autovacuum = off and > autovacuum_max_workers = 1 (or a low number) is an extremely rare > case. I think it would be better to stabilize these tests. One idea is > to turn the autovacuum GUC parameter on while setting > autovacuum_enabled = off for each table. That way, we can ensure that > autovacuum workers are launched. And I think it seems to align real > use cases. > > Regards, > > [1] > https://www.postgresql.org/message-id/02373ec3-50c6-df5a-0d65-5b9b1c0c86d6%40gmail.com > > > OK, do you want to propose a patch? > > Yes, I'll prepare and share it soon. > > I've attached the patch. Could you please test if the patch fixes the > instability you observed? > > Since we turn off autovacuum on all three tests and we wait for > autovacuum to complete processing databases, these tests potentially > have a similar (but lower) risk. So I modified these tests to turn it > on so we can ensure the autovacuum runs periodically. > > > I assume you actually meant to remove the "autovacuum = off" in > 003_wraparound.pl. With that change in your patch I retried my test, but on > iteration 100 out of 100 it failed on test 002_limits.pl. >
I think we need to remove the "autovacuum = off' also in 002_limits.pl as it waits for autovacuum to process both template0 and template1 databases. Just to be clear, the failure happened even without "autovacuum = off"? Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
