Re: xid_wraparound tests intermittent failure.

On Mon, Jul 22, 2024 at 12:53 PM Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
>
>
> On 2024-07-22 Mo 12:46 PM, Tom Lane wrote:
>
> Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> writes:
>
> Looking at dodo's failures, it seems that while it passes
> module-xid_wraparound-check, all failures happened only during
> testmodules-install-check-C. Can we check the server logs written
> during xid_wraparound test in testmodules-install-check-C?
>
> Oooh, that is indeed an interesting observation. There are enough
> examples now that it's hard to dismiss it as chance, but why would
> the two runs be different?
>
>
> It's not deterministic.
>
> I tested the theory that it was some other concurrent tests causing the issue, but that didn't wash. Here's what I did:
>
> for f in `seq 1 100`
> do echo iteration = $f
> meson test --suite xid_wraparound || break
> done
>
> It took until iteration 6 to get an error. I don't think my Ubuntu instance is especially slow. e.g. "meson compile" normally takes a handful of seconds. Maybe concurrent tests make it more likely, but they can't be the only cause.

Could you provide server logs in both OK and NG tests? I want to see
if there's a difference in the rate at which tables are vacuumed.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com