Re: Race condition in server-crash testing

Andres Freund <andres@anarazel.de> writes:
> On 2022-04-04 00:50:27 -0400, Tom Lane wrote:
>> It's hard to be totally sure, but I think what happened is that
>> gaur hit the in-hindsight-obvious race condition in this code:
>> we managed to execute a successful iteration of poll_query_until
>> before the postmaster had noticed its dead child and commenced
>> the restart.  The test lines after these are not prepared to see
>> failure-to-connect.
>> It's not obvious to me how to remove this race condition.
>> Thoughts?

> Maybe we can use pump_until() with the psql that's not getting killed? With a
> non-matching regex? That'd only return once the backend was killed by
> postmaster, afaics?

Good idea.  What I actually did was to borrow the recently-fixed code
in 013_crash_restart.pl that checks for psql's "connection lost"
report.

            regards, tom lane