Re: file-locking and postmaster.pid

On Tuesday 23 May 2006 17:54, Tom Lane wrote:
> Andreas Joseph Krogh <andreak(at)officenet(dot)no> writes:
> > I've experienced several times that PG has died somehow and the
> > postmaster.pid file still exists 'cause PG hasn't had the ability to
> > delete it upon proper shutdown. Upon start-up, after such an incidence,
> > PG tells me another PG is running and that I either have to shut down the
> > other instance, or delete the postmaster.pid file if there really isn't
> > an instance running. This seems totally unnecessary to me.
>
> The postmaster does check to see whether the PID mentioned in the file
> is still alive, so it's not that easy for the above to happen. If you
> can provide details of a scenario where a failure is likely, we'd like
> to know about it. Also, what PG version are you talking about?

I have experienced this with PG-8.1.3 and will provide details if I can make
it happen. Basically it has happened when I have had to "hard-reset" my
laptop due to some strange bugs in Linux which have made it hang.

> > Why doesn't PG use file-locking to tell if another
> > PG is running or not?
>
> Portability.

Ok.

--
Andreas Joseph Krogh <andreak(at)officenet(dot)no>
Senior Software Developer / Manager
gpg public_key: http://dev.officenet.no/~andreak/public_key.asc
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