Re: FATAL: bogus data in lock file "postmaster.pid": ""

On Thu, Jan 5, 2012 at 14:18, Heikki Linnakangas
<heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> My laptop ran out of battery and turned itself off while I was just starting
> up postmaster. After plugging in the charger and rebooting, I got the
> following error when I tried to restart PostgreSQL:
>
> FATAL:  bogus data in lock file "postmaster.pid": ""
>
> postmaster.pid file was present in the data directory, but had zero length.
> Looking at the way the file is created and written, that can happen if you
> crash after the file is created, but before it's written/fsync'd (my laptop
> might have write-cache enabled, which would make the window larger).
>
> I was a bit surprised by that. That's probably not a big deal in practice,
> but I wonder if there was some easy way to avoid that. First I thought we
> could create the new postmaster.pid file with a temporary name and rename it
> in place, but rename(2) will merrily overwrite any existing file which is
> not what we want. We could use link(2), I guess.

Is this really a problem big enough to spend even that much effort on?

Perhaps a special-case in the error message instead is enough?

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/