Re: Backends "hanging" with strace showing selects?

Поиск
Список
Период
Сортировка
От hubert depesz lubaczewski
Тема Re: Backends "hanging" with strace showing selects?
Дата
Msg-id 20101115200001.GA18863@depesz.com
обсуждение исходный текст
Ответ на Re: Backends "hanging" with strace showing selects?  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-general
On Mon, Nov 15, 2010 at 02:52:16PM -0500, Tom Lane wrote:
> hubert depesz lubaczewski <depesz@depesz.com> writes:
> > hi
> > had strange situation today.
>
> > very high load, cpu saturated (and this machine has lots of cores).
>
> > i straced one of backends that was using lots of cpu (it was doing some
> > select, but I don't know what as i wasn't able to start psql).
>
> > strace looked like this:
> > select(0, NULL, NULL, NULL, {0, 1000})  = 0 (Timeout)
> > select(0, NULL, NULL, NULL, {0, 1000})  = 0 (Timeout)
> > select(0, NULL, NULL, NULL, {0, 1000})  = 0 (Timeout)
> > select(0, NULL, NULL, NULL, {0, 1000})  = 0 (Timeout)
>
> That suggests a lot of contention for a spinlock, but without any
> information about what the system was really doing, it's hard to go
> further than that.

we had ~ 700 active connections, but it is virtually impossible to tell
what they were doing, as I couldn't connect to get pg_stat_activity.

Best regards,

depesz

--
Linkedin: http://www.linkedin.com/in/depesz  /  blog: http://www.depesz.com/
jid/gtalk: depesz@depesz.com / aim:depeszhdl / skype:depesz_hdl / gg:6749007

В списке pgsql-general по дате отправления:

Предыдущее
От: Matthew Walden
Дата:
Сообщение: Re: Expected frequency of auto_vacuum activity
Следующее
От: Greg Smith
Дата:
Сообщение: Re: The first dedicated PostgreSQL forum