Re: Adding more memory = hugh cpu load

Em 10-10-2011 23:19, Claudio Freire escreveu:
> On Tue, Oct 11, 2011 at 12:02 AM, Samuel Gendler
> <sgendler(at)ideasculptor(dot)com> wrote:
>> The original question doesn't actually say that performance has gone down,
>> only that cpu utilization has gone up. Presumably, with lots more RAM, it is
>> blocking on I/O a lot less, so it isn't necessarily surprising that CPU
>> utilization has gone up. The only problem would be if db performance has
>> gotten worse. Maybe I missed a message where that was covered? I don't see
>> it in the original query to the list.
>
> Load average (which is presumably the metric in question) includes
> both processes using the CPU and processes waiting for I/O.
> So it *would* be strange for load average to go up like that, if
> database configuration remains the same (ie: equal query plans)

Yep, that's the point. Iostat and vmstat reports a very low use of the
disks (lower than before the changes are made - perhaps because the cache).
Nothing changed in database itself.