Re: Need a debugging tip or two - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Need a debugging tip or two
Date
Msg-id 24877.973642361@sss.pgh.pa.us
Whole thread Raw
In response to Re: Need a debugging tip or two  (Peter Eisentraut <peter_e@gmx.net>)
Responses Re: Need a debugging tip or two
List pgsql-hackers
Peter Eisentraut <peter_e@gmx.net> writes:
> There's probably little reason to start a backend standalone.  If you want
> to do stock-of-the-trade debugging you simply start a postmaster, then
> psql (or whatever floats your boat), and attach gdb to the resulting
> backend process.

Right, that's what I always do (unless I have to debug a crash at initdb
time :-().  A tip here is that you can even debug backend-startup-time
problems this way, and no you don't have to be superhumanly quick on the
trigger: you set PGOPTIONS="-W n" in the environment of psql.  This
will cause an n-second sleep() call very early in the backend startup
process.  I find 30 seconds plenty of time to run ps, start gdb, and
attach.  You can also throw in things like "-d2" to crank up the
postmaster log level for just the backend under test.

I thought this lore was in the developer's FAQ already, but I don't
see it there at the moment.  Bruce, is it lurking someplace else?
        regards, tom lane


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: Issue NOTICE for attempt to raise lock level?
Next
From: Thomas Lockhart
Date:
Subject: Committed patches; initdb required