From: Mischa Sandberg <mischa_sandberg@telus.net>
To: pgsql-admin@postgresql.org
Subject: Re: Reliably determining whether the server came up
Date: Tue, 18 Nov 2008 11:06:50 -0800
Message-ID: <1227035210.4923124a948e9@legacywebmail.telus.net> (raw)
In-Reply-To: <22317.1227032425@sss.pgh.pa.us>
References: <1226527535.491b532f4c45e@legacywebmail.telus.net>
<491F1861.4060403@reedyriver.com>
<1226780945.491f3111e22de@legacywebmail.telus.net>
<1226781115.22056.1.camel@jd-laptop.pragmaticzealot.org>
<49200BD8.4060703@reedyriver.com>
<1226989027.49225de368848@legacywebmail.telus.net>
<20048.1227023982@sss.pgh.pa.us>
<1227026844.4922f19ce4c77@legacywebmail.telus.net>
<22317.1227032425@sss.pgh.pa.us>
Quoting Tom Lane <tgl@sss.pgh.pa.us>:
> Mischa Sandberg <mischa_sandberg@telus.net> writes:
> > Quoting Tom Lane <tgl@sss.pgh.pa.us>:
> >> I'd bet that the pg_ctl status part is failing. I get exit status
> 1
> >> from it if there's no server running.
>
> > Yes, that was part of the problem with the original startup
> script;
> > postmaster hadn't even gotten as far as writing postmaster.pid,
> > I guess. But pg_ctl status returning 1 could also mean that that
> the
> > server had come up, hit a critical problem and exited. Hence my
> problem;
> > this has to detect server failure, reliably, as well.
>
> You could sleep for a second or so *before* you start looking for
> the
> pidfile.
The systems are under erratic load, due to concurrent
cpu and diskio spikes around start-up time.
1-2 secs is not enough to be a guarantee :-(
Probably not explaining the issues well;
caught between two constraints that aren't really pg's problem;
and wide clusters with automated admin, variable hardware
and spikes of db restarts are no doubt an oddball edge case.
There are workarounds; was hoping for something
clean and obvious (to all but me).
Switching back to tailing the log files and moving on.
Thanks everyone.
--
Engineers think that equations approximate reality.
Physicists think that reality approximates the equations.
Mathematicians never make the connection.
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To: pgsql-admin@postgresql.org
Cc: mischa_sandberg@telus.net
Subject: Re: Reliably determining whether the server came up
In-Reply-To: <1227035210.4923124a948e9@legacywebmail.telus.net>
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