Re: Backend process is still runs even postmaster got killed

On Fri, Dec 7, 2012 at 10:21 AM, Hari Babu <haribabu(dot)kommi(at)huawei(dot)com>wrote:

> Backend processes are still running even if the postmaster got killed and
> all other server processes are exited by checking the****
>
> Postmaster status. ****
>
> ** **
>
> And the backend process is providing the service to the client.****
>
> Is there any problems are possible? If we continue the system for a long
> time with the above behavior?****
>
> ** **
>
> Until all these kind of backend processes are exited, postmaster is
> failing to start.****
>
> Manual cleanup is required for these backend processes? Or is there anyway
> we can handle?****
>
> ** **
>
> Regards,****
>
> Hari babu.****
>
>
>

Hi Hari.

How exactly do you kill the postmaster? It is suggested you use pg_ctl for
server shutdowns/restarts. Check out the option -m:
-m SHUTDOWN-MODE can be "smart", "fast", or "immediate"
Shutdown modes are:
smart quit after all clients have disconnected
fast quit directly, with proper shutdown
immediate quit without complete shutdown; will lead to recovery on
restart

"Smart" will wait for all your backend processes to terminate (or fail if
it takes too long). If i remember correctly "fast" will cause the
postmaster to exit even if backends are still up, the equivalent of sending
a kill -15 (SIGTERM). And "immediate" is like sending a kill -9 (SIGKILL)
i.e. violent shutdown of everything.

I'm guessing you went for the equivalent of SIGTERM that's why you still
have backends running.

regards,
--thalis