Re: Load problems...

Daniel Andersen <zedar@free2air.com.au> writes:
> [4059] DEBUG: connection startup failed (fork failure): Resource
> temporarily unavailable
> [4059] DEBUG: could not launch checkpoint process (fork failure): Resource
> temporarily unavailable

Hmm ... a fork failure suggests resource exhaustion somewhere in the
kernel.  Do you have enough swap space?  A large enough NFILE (kernel
filetable size) setting?

> there are generally up to 200 copies of postmaster running at any given time,

200 * a few dozen open files per backend is a lot of open files.  I'm
betting on NFILE being the issue, myself.

Linuxen tend to lie through their teeth about the number of open files
they can support per-process (sysconf(_SC_OPEN_MAX)).  In 7.2 you can
compensate for that by setting PG's config variable
max_files_per_process to something sane, maybe 50 to 100.

You'll still need to make sure that the kernel is configured to support
max_files_per_process * max_connections open files, but at least that's
a definable number now.

            regards, tom lane