Re: Force update_process_title=on in crash recovery?

On Tue, Sep 15, 2020 at 10:01:18AM -0400, Tom Lane wrote:
> Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
> > Based on a couple of independent reports from users with no idea how
> > to judge the progress of a system recovering from a crash, Christoph
> > and I wondered if we should override update_process_title for the
> > "recovering ..." message, at least until connections are allowed. We
> > already do that to set the initial titles.
>
> > Crash recovery is a rare case where important information is reported
> > through the process title that isn't readily available anywhere else,
> > since you can't log in. If you want to gauge progress on a system
> > that happened to crash with update_process_title set to off, your best
> > hope is probably to trace the process or spy on the files it has open,
> > to see which WAL segment it's accessing, but that's not very nice.
>
> Seems like a good argument, but you'd have to be careful about the
> final state when you stop overriding update_process_title --- it can't
> be left looking like it's still-in-progress on some random WAL file.
> (Compare my nearby gripes about walsenders being sloppy about their
> pg_stat_activity and process title presentations.)

Related:
https://commitfest.postgresql.org/29/2688/

I'm not sure I understood Michael's recent message, but I think maybe refers to
promotion of a standby.

--
Justin