Re: xid_wraparound tests intermittent failure. - Mailing list pgsql-hackers
From | Masahiko Sawada |
---|---|
Subject | Re: xid_wraparound tests intermittent failure. |
Date | |
Msg-id | CAD21AoBHZUmxuPnUcQ+Fen9z_1-DWLdFDzoAd=Qc4XbU9gf7CQ@mail.gmail.com Whole thread Raw |
In response to | Re: xid_wraparound tests intermittent failure. (Andrew Dunstan <andrew@dunslane.net>) |
Responses |
Re: xid_wraparound tests intermittent failure.
|
List | pgsql-hackers |
On Sat, Jul 27, 2024 at 1:06 PM Andrew Dunstan <andrew@dunslane.net> wrote: > > > On 2024-07-26 Fr 1:46 PM, Masahiko Sawada wrote: > > On Thu, Jul 25, 2024 at 6:52 PM Andrew Dunstan <andrew@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.mshk@gmail.com> wrote: > >> > >> On Thu, Jul 25, 2024 at 10:56 AM Andrew Dunstan <andrew@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 Iretried 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"? > > > > The attached patch, a slight modification of yours, removes "autovacuum > = off" for all three tests, and given that a set of 200 runs was clean > for me. Oh I missed that I left "autovacuum = off' for some reason in 002 test. Thank you for attaching the patch, it looks good to me. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
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