Re: SIGUSR1 pingpong between master na autovacum launcher causes crash

Tom Lane wrote:
> Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> > Zdenek Kotala wrote:
> >> Just a confirmation that Alvaro's patch+ReleasePostmasterChildSlot() fix
> >> solves the problem and PostgreSQL survives well during a memory
> >> shortages.
>
> > So this patch would do it.
>
> Looks good to me, but I think you should also increase the avlauncher
> delay from 100ms -> 1s as Zdenek suggested.

Committed with this change.

> > I think this stuff about postmaster child slots is later than
> > launcher/worker split. I don't recall seeing it before.
>
> Yeah, I added that recently to try to detect postmaster children
> that exit without cleaning up properly. I seem to have missed this
> error case :-(. Actually it looks like fork failure for regular
> backends gets it wrong too :-( :-( --- would you please also add one
> in the pid<0 path in BackendStartup? I think this logic is in 8.4
> too, in which case it'll need to be back-patched.

And this one too.

Thanks!

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.