Re: file-locking and postmaster.pid

On Tue, May 23, 2006 at 01:36:41PM -0400, Tom Lane wrote:
> This is exactly what you should NOT do.
>
> A start script that thinks it is smarter than the postmaster is almost
> certainly wrong.  It is certainly dangerous, too, because auto-deleting
> that pidfile destroys the interlock against having two postmasters
> running in the same data directory (which WILL corrupt your data,
> quickly and irretrievably).  All it takes to cause a problem is to
> use the start script to start a postmaster, forgetting that you already
> have one running ...

I do agree with you that we should not play games with postmaster.
Better to be safe than sorry. (So, manually deleting pid file is the
only safe option). I was just suggestion (possibly dangerous)
workaround.

Btw, I do check for running postmaster, using full path (I don't wan to
kill every postmaster on the system), is this safe? Or there could be
race condition?