On Mon, Jan 6, 2014 at 6:06 PM, Anand Kumar, Karthik
<Karthik.AnandKumar@classmates.com> wrote:
> Hi,
>
> We run postgres 9.1.11, on Centos 6.3, and an ext2 filesystem
>
> Everything will run along okay, and every few hours, for about a couple of
> minutes, postgres will slow way down. A "select 1" query takes between 10
> and 15 seconds to run, and the box in general gets lethargic.
>
> This causes a pile up of connections at the DB, and we run out of
> max_connections.
>
> This is accompanied with a steep spike in system CPU and load avg. No spike
> in user CPU or in I/O.
As well as the previously mentioned huge pages thing, also look at vm
dirty ratio:
http://www.westnet.com/~gsmith/content/linux-pdflush.htm