Re: Increasing number of PG connections.

On 2 Feb 2004 at 16:45, scott.marlowe wrote:

> Do you have the cache set to write back or write through? Write through
> can be a performance killer. But I don't think your RAID is the problem,
> it looks to me like postgresql is doing a lot of I/O. When you run top,
> do the postgresql processes show a lot of D status? That's usually waiting
> on I/O
>

Actually I'm not sure. It's setup with the factory defaults from IBM. Actually when I
start hitting the limit I was surprised to find only a few D status indicators. Most of the
processes where sleeping.

> what you want to do is get the machine to a point where the kernel cache
> is about twice the size or larger, than the shared_buffers. I'd start at
> 10000 shared buffers and 4096 sort mem and see what happens. If you've
> still got >2 gig kernel cache at that point, then increase both a bit (2x
> or so) and see how much kernel cache you've got. If your kernel cache
> stays above 1Gig, and the machine is running faster, you're doing pretty
> good.
>

I've set shared to 10000 and sort to 4096. I just have to wait until the afternoon
before I see system load start to max out. Thanks for the tips I'm crossing my
fingers.

--
Kevin Barnard