Re: prevent immature WAL streaming

On 2021-Nov-09, Tom Lane wrote:

> This is still happening off and on, which makes it look like a
> timing-sensitive problem. Confirming that, I can make it fail
> every time by adding a long sleep just ahead of where
> 026_overwrite_contrecord.pl captures $initfile. On reflection
> I think the problem is obvious: if autovacuum does anything
> concurrently with the test's startup portion, it will cause the
> carefully-established WAL insertion point to move into the
> next segment. I propose to add "autovacuum = off" to the
> test's postmaster configuration.

Ooh, of course.

> Also, I think we want
>
> -ok($initfile != $endfile, "$initfile differs from $endfile");
> +ok($initfile ne $endfile, "$initfile differs from $endfile");
>
> The existing coding works as long as all characters of these
> WAL segment names happen to be decimal digits, but ...

Argh!

Thanks for taking care of these issues.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"La conclusión que podemos sacar de esos estudios es que
no podemos sacar ninguna conclusión de ellos" (Tanenbaum)