Re: Options for growth

On Thu, 16 Jan 2003, D'Arcy J.M. Cain wrote:

> Due to the fact that we are growing out of our current system
> (PostgreSQL on PCs) we are looking for ways to expand and one of the
> suggestions has been to toss PostgreSQL in favour of Oracle with
> Remote Access Cluster (RAC) software. The theory is that you can just
> plug machines into the cluster if the database appears to be straining
> and they automagically take over some of the load.
> ...
> My idea is to create a new middleware layer that allows me to split
> things up based on various criteria without changing my application.

It's a basic principle of clustering that doing it in an application-
aware way will always be more efficient than trying to hide it from the
application.

If you've not read it already, I strongly suggest reading _In Search of
Clusters_ by Gregory F. Pfister.

> And finally, if you had your dream machine to run on, what would it
> be? We are also looking outside of PC hardware but we are concerned
> about not having access to that nice, cheap, generic hardware for when
> we need to grow again or for redundant backup.

If you can manage to stick with PC hardware, you are going to save a
*lot* of money. If you're considering buying a reasonably well loaded
Sun E6000 or similar, it's well worth spending twenty or thirty thousand
dollars on a big PC system and spending some time to see if that will do
the trick before you shell out a couple hundred thousand for the Sun.

As for how well postgres uses multiple CPUs: so long as you've got lots
of connections with the load distributed among them, it's dependent on
the OS, postgres. If the OS can handle the scheduling (which, last I
checked, Linux couldn't, at least not without patches), eight or sixteen
CPUs will be fine.

cjs
--
Curt Sampson <cjs(at)cynic(dot)net> +81 90 7737 2974 http://www.netbsd.org
Don't you know, in this new Dark Age, we're all light. --XTC