Re: [PATCH] If a worker process crashes during shutdown, dump core and prevent restarts

On Sat, 20 Nov 2010 00:45:21 +0300, Dmitry Kurochkin
<dmitry.kurochkin_at_measurement-factory.com> wrote:
> If a worker process crashes during shutdown, dump core and prevent
> restarts.
>
> Before the change, if a worker process crashes during shutdown, death()
> handler would exit with code 1, and master process would restart the
> worker. Now workers send SIGUSR1 to master when shutting down. When
> master process gets the SIGUSR1 signal, it stops restarting workers.
>
> SIGUSR1 is already used for log rotation, but it is fine to use SIGUSR1
> for master process shutdown notifications because master is never
> responsible for both log rotation and kid restarts.
>
> Terminate with abort(3) instead of exit(3) to leave a core dump if Squid
> worker crashes during shutdown.
>
> Also the patch fixes potential infinite loop in master process. Master
> finished only when all kids exited with success, or all kids are
> hopeless, or all kids were killed by a signal. But in cases like when
> part of kids are hopeless and other were killed, master process would
> not exit. After the change master exits when there are no running kids
> and no kids should be restarted.
>
> Add syslog notice if kid becomes hopeless.
>
> Regards,
> Dmitry

This seems to me a cleaner implementation of the kill-parent hack. Thank
you.

+0. (seems right by reading, but I can't evaluate it properly yet.)

Amos
Received on Tue Nov 23 2010 - 23:58:21 MST