Re: postmaster dies (was Re: Very disappointing performance)

Tom Lane wrote:

> secret <secret@kearneydev.com> writes:
> > ERROR:  postmaster: StreamConnection: accept: Invalid argument
> > server_fd = 3, port = 0x816aa70
>
> >     There we go, it crashed this morning...(interestingly it went all of
> > yesterday without crashing)... Does this shed some light?
>
> Not much ... it shows pretty much what we expected, ie, nothing
> obviously wrong.
>
> What I would suggest doing next is running the postmaster under 'truss'
> or some similar utility that can generate a logfile of all the kernel
> calls made by the postmaster.  I can't give you any details on how to do
> that --- perhaps some other reader can help?  What we're looking for is
> anything that might have changed the state of file descriptor 3 shortly
> before the crash.
>
> BTW, some tips on debugging this.  Maybe these are obvious, maybe not:
>
> 1. This accept call is not associated with normal query processing, but
> with receiving connection requests from new clients.  Almost certainly
> the bug is not triggered by processing queries but by connection
> attempts.  You probably could make the crash happen sooner by starting
> and stopping clients in a steady stream (not that you want a crash
> sooner on your real system, of course, but for debugging it'd be nice
> not to have to wait for long).
>
> 2. You might want to build a playpen system that you can stress into
> crashing without taking out your live server.  The easiest way to do
> that is just to duplicate your installation on another machine, but if
> no other machine is handy (or if you suspect a platform-dependent bug,
> which I do here) the best bet is to build a debugging version of
> Postgres that has nonstandard values for the installation directory
> and server's port address.  For example I usually build trial versions
> with
>
> ./configure --with-pgport=5440 --prefix=/users/postgres/testversion
>
> (plus any options you normally use, of course).  I think it might also
> be possible to set these values while running initdb and starting the
> test postmaster, without having to recompile; but I don't know the
> exact incantations to use to do it that way.
>
>                         regards, tom lane
   Would strace work instead of truss?  I have strace... Will you be able to
interpret the strace files & determine the problem do you think?
   You've been the only one to respond on this, so I'm a tad worried about
being left out in the cold on this one... I'd be glad to pay for support if
there is a place I can do that, heck I pay for support on other software
products, why not PostgreSQL?
   Please let me know.  I'll begin an strace tonight...

David