Re: PostgreSQL running out of file handles

Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au> writes:
> A few days back the load increased on our database server to the point
> where it could not get enough file handles. This causes the backends to
> crash, get restarted only to crash again, on and on.

> We fixed it by bumping kern.maxfiles, but was just wondering if this is
> a scenario that PostgreSQL should handle more gracefully?

I suppose you are running on some BSD variant? BSD is notorious for
promising more than it can deliver with respect to number of open files
per process. This is a kernel bug, not a Postgres bug.

You can adjust Postgres' max_files_per_process setting to compensate for
the kernel's lying about its capabilities.

(Postgres is in fact one of the most robust applications I know of
in terms of not going belly-up in response to EMFILE or ENFILE.
However, if there are not any spare descriptors to close, there's
not a lot we can do except fail.)

regards, tom lane