Re: BUG #5284: Postgres CPU 100% and worker took too long to start; cancelled... Systemdown

On Mon, Jan 18, 2010 at 12:43 AM, azuneko <azuneko(at)hotmail(dot)com> wrote:
> The following bug has been logged online:
>
> Bug reference:      5284
> Logged by:          azuneko
> Email address:      azuneko(at)hotmail(dot)com
> PostgreSQL version: 8.3.3
> Operating system:   FreeBSD7.0.2
> Description:        Postgres CPU 100% and worker took too long to start;
> cancelled... Systemdown
> Details:
>
> Hello,
>
> I have the following 2 problems.
> It would be appreciated if you give me some information such as the way to
> avoid them.(Or if those problems are already known and fixed, could you
> please tell me what version I should apply.)
>
> 1,CPU utilization of postgres reaches 100%.
>
> I excuted "top" command and sometimes found that CPU utilization of postgres
> process reached 100% or almost 100%. (This is similar to the problem that
> was posted at
> http://archives.free.net.ph/message/20081104.074244.6e0dbcde.ja.html.)
> What might be the cause?
>
> 2. The following warning can be seen in the postgres log.
>        WARNING:  worker took too long to start; cancelled
>
> After this warning firstly appears in the log, the same warining message
> seems to be repeated. And if you leave this state as it is, the OS freezes
> before long. I guess this event happens because the daemons related to
> postgres (such as vacuum and autovacuum) won't release the shared memory and
> exclusively keep using it. Am I correct?
>
> Those 2 problems are confirmed to happen at least under the following
> conditions;
>        Software
>         -OS : FreeBSD 7.0.2
>         -Postgres version : 8.3.3
>        Hardware
>         -Disk configuration : RAID5 (MegaCLI)
>         -CPU : Xeon2.4
>
> Thank you.

You haven't really provided us with much detail here, but it kind of
sounds like your system is overloaded.

...Robert