Re: oom_killer

On Thu, Apr 21, 2011 at 11:15 AM, Tory M Blue <tmblue(at)gmail(dot)com> wrote:

> While I don't mind the occasional slap of reality. This configuration
> has run for 4+ years. It's possible that as many other components each
> fedora release is worse then the priors.

How many of those 300 max connections do you generally use? If you've
always used a handful, or you've used more but they weren't memory
hungry then you've been lucky.

work_mem is how much memory postgresql can allocate PER sort or hash
type operation. Each connection can do that more than once. A
complex query can do it dozens of times. Can you see that going from
20 to 200 connections and increasing complexity can result in memory
usage going from a few megabytes to something like 200 connections *
100Megabytes per sort * 3 sorts = 60Gigabytes.

> The Os has changed 170 days ago from fc6 to f12, but the postgres
> configuration has been the same, and umm no way it can operate, is so
> black and white, especially when it has ran performed well with a
> decent sized data set for over 4 years.

Just because you've been walking around with a gun pointing at your
head without it going off does not mean walking around with a gun
pointing at your head is a good idea.