Re: Performance Woes

> I have several databases. They are each about 35gb in size and have about
> 10.5K relations (count from pg_stat_all_tables) in them. Pg_class is
> about 26k rows and the data directory contains about 70k files. These are
> busy machines, they run about 50 xactions per second, ( aproxx insert /
> update / delete about 500 rows per second).
>
> We started getting errors about the number of open file descriptors
>
> : 2007-05-09 03:07:50.083 GMT 1146975740: LOG: 53000: out of file
> descriptors: Too many open files; release and retry
>
> 2007-05-09 03:07:50.083 GMT 1146975740: CONTEXT: SQL statement "insert
> ….. "
>
> PL/pgSQL function "trigfunc_whatever" line 50 at execute statement
>
> 2007-05-09 03:07:50.083 GMT 1146975740: LOCATION: BasicOpenFile, fd.c:471
>
> 2007-05-09 03:07:50.091 GMT 0: LOG: 00000: duration: 12.362 ms
>
> 2007-05-09 03:07:50.091 GMT 0: LOCATION: exec_simple_query, postgres.c
> :1090
>
>
>
> So we decreased the max_files_per_process to 800. This took care of the
> error **BUT** about quadrupled the IO wait that is happening on the
> machine. It went from a peek of about 50% to peeks of over 200% (4 processor
> machines, 4 gigs ram, raid). The load on the machine remained constant.
>

What version of Pg/OS? What is your hardware config?

I had seen these errors with earlier versions of Pg 7.4.x which was fixed in
later releases according to the changelogs