Re: [COMMITTERS] pgsql: Improve corner cases in pg_ctl's new wait-for-postmaster-startup

On Sat, May 28, 2011 at 3:13 AM, Tom Lane  wrote:
> Also, if the postmaster.pid file is not there at any point after we've
> waited 5 seconds, assume the postmaster has failed and report that, rather
> than almost-certainly-fruitlessly continuing to wait.  The pidfile should
> appear almost instantly even when there is extensive startup work to do,
> so 5 seconds is already a very conservative figure.  This part is per a
> gripe from MauMau --- there might be better ways to do it, but nothing
> simple enough to get done for 9.1.

The postmaster.pid can remain even after the server dies, for example,
in the case where it dies with PANIC or SIGKILL. To address this corner
case, we should check whether postmaster is really running by sending
the signal 0 after we read postmater.pid file? Attached patch does that.

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center