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

On 11/23/2010 04:58 PM, Amos Jeffries wrote:
> 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.)

I am going to commit this change if there are no new objections.

Thank you,

Alex.
Received on Tue Mar 29 2011 - 21:04:56 MDT