"Anand Kumar, Karthik" <karthik.anandku...@classmates.com> writes: > 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.
System CPU only huh? There have been some reports of such behavior apparently caused by inefficiencies in the kernel's support of "transparent huge pages". See for instance this thread http://www.postgresql.org/message-id/flat/cabmvzl2y8mrm5c9xxejaydqe0i1s78rae3ceatgynf5ktz_...@mail.gmail.com although it looks like in that case the real fix was to reduce the number of backends. > We do typically have a lot of idle connections (1500 connections total, over > a 1000 idle at any given time). We're in the midst of installing pgbouncer to > try and mitigate the problem, but that still doesn't address the root cause. 1500 connections? What makes you think that itself isn't the root cause? regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
