Re: Reliably determining whether the server came up

Mischa Sandberg <mischa_sandberg(at)telus(dot)net> writes:
> Quoting Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)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.

> In another vein, another place where there are consistent
> failures is in the sequence:

> createlang ... -d template1 plpgsql
> createdb $PGDATABASE
> <app>

This should be fixed in 8.3 and up. In older releases about all you
can do is delay a second or so to let the old backend exit.

regards, tom lane