Re: Logical replication launcher did not automatically restart when got SIGKILL

Fujii Masao <masao.fujii@gmail.com>

From: Fujii Masao <masao.fujii@gmail.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: cca5507 <cca5507@qq.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, pgsql-hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-07-24T09:09:01Z
Lists: pgsql-hackers
On Thu, Jul 17, 2025 at 6:58 PM shveta malik <shveta.malik@gmail.com> wrote:
>
> On Wed, Jul 16, 2025 at 8:51 AM cca5507 <cca5507@qq.com> wrote:
> >
> > Hi,
> >
> > The v1-0002 in [1] will call ReportBackgroundWorkerExit() which will send SIGUSR1 to 'bgw_notify_pid', but it may already exit in HandleChildCrash(), is this ok?
> >
>
> Shall ReportBackgroundWorkerExit() be skipped for 'crashed' background worker?
>
> If we look at code prior to commit 28a520c0b77, there we were setting
> 'rw_crashed_at' in CleanupBackgroundWorker() and then
> HandleChildCrash() was resetting the pid and exiting with no
> additional processing.

It seems we don't need to set rw_crashed_at in crash cases,
since it's always reset to 0 by ResetBackgroundWorkerCrashTimes()
in restart-after-crash code. So, the only additional step we need may be
resetting rw_pid to 0.

Instead of modifying CleanupBackend() to do this, another option
could be to reset rw_pid during restart-after-crash code, for example,
inside ResetBackgroundWorkerCrashTimes(). Thought?

Regards,

-- 
Fujii Masao



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add regression test for background worker restart after crash.

  2. Fix background worker not restarting after crash-and-restart cycle.

  3. Refactor code to handle death of a backend or bgworker in postmaster