Re: How to analyze load average ?

> I think load avg is high because before I change the servers my produce
> server
> was on 16 cpu, 24 gb memory and load avg on that server was 0.24.
> Database is the same,
> users that use the server is the same, nothing is changed. I dump the DB
> from old server
> and import it to new one before few days ago and because that is the new
> server with more
> resource I monitor his load avg and I think is too high. For that reason
> Im asking is there
> a way to detect why my load avg is 0.88. When I run select * from
> pg_stat_activity;
> did not see more then 3-4 query that isn't much complicated and I
> already try them with
> explain to see what is the result.

Well, the load average is a bit difficult to analyze because of the
exponential damping. Also, I find it a bit artificial and if there are
no sudden peaks or slowdowns I wouldn't bother analyzing this.

A wild quess is that the new server has more CPUs but at lower
frequency, therefore the tasks run longer and impact the load average
accordingly. There are other such things (e.g. maintenance of larger
shared buffers takes more time).

Have you verified that the performance of the new hardware matches
expectations and that it's actually faster than the old server?

> I know what load average mean, I was OpenBSD user a few years, now I
> use Slackware with kernel 3.5.

So you do have 3.5 on production? Wow, you're quite adventurous.

Tomas