Re: pg_ctl restart - behaviour based on wrong instance

Fujii Masao wrote:
> On Sat, Mar 19, 2011 at 10:20 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> > On Fri, Mar 18, 2011 at 1:19 PM, Erik Rijkers <er(at)xs4all(dot)nl> wrote:
> >> This is OK and expected. ?But then it continues (in the logfile) with:
> >>
> >> FATAL: ?lock file "postmaster.pid" already exists
> >> HINT: ?Is another postmaster (PID 20519) running in data directory
> >> "/var/data1/pg_stuff/pg_installations/pgsql.vanilla_1/data"?
> >>
> >> So, complaints about the *other* instance. ?It doesn't happen once a successful start (with pg_ctl
> >> start) has happened.
> >
> > I'm guessing that leftover postmaster.pid contents might be
> > responsible for this?
>
> The cause is that "pg_ctl restart" uses the postmaster.opts which was
> created in the primary. Since its content was something like
> "pg_ctl -D vanilla_1/data", vanilla_1/data/postmaster.pid was checked
> wrongly.

FYI, my The Magic of Hot Streaming Replication talk shows this exact
issue on slide 16:

http://momjian.us/main/presentations/features.html#hot_streaming

Remove /data2/postmaster.pid so the standby server does not see the
primary servers pid as its own:

rm /u/pg/data2/postmaster.pid

This is because my demo creates the standby on the same machine as the
master so the pid is still valid and owned by 'postgres', which is what
the user is reporting.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +