Re: run httpd and postgresql on different machines ?

Chuming Chen wrote:
>
> I want to set up a web site using apache httpd, php and postgresql. From
> the performance point of view, which architecture is better? 1) Run
> httpd and postgresql on the same machine; 2) Run postgresql on seperate
> machine. My concern is that the machine I am going to run httpd has
> limitted storage. I am expecting the increasing of postgresql database
> once I set it ip.

I had good luck with 4 very cheap (small, used, 1CPU, IDE disk)
machines running httpd/php/MONO-ASP.NET, and 1 more expensived
machine (with some internal failover capabilities - dual power
supplies, with a RAID array, with a support contract) running
postgresql.

The reasoning was one of cost/performance with the ability to
have likely-to-fail components fail with no downtime.

The cheapest way to scale the front-end machines with failover
capabilities was to use sub-$1000 slightly obsolete PCs.
The cheapest way I knew to provide limited scalability
and failover (at least for disk) for a database was a raid array.

With some of the newer replication features or pgpool, it might
be easier to scale "out" instead of "up"; but I have no experience
making that determination.

How about the rest of you guys....

If CPU demands in my database get to the point of needing 5-CPUs
with a read-mostly (90%) system, am I better off with
1 lots of replication between small servers
or
2 scaling up a big server.

(the reason I'm CPU bound instead of disk bound is that many
of my queries are spatial operations with PostGIS like unions
and buffers of polygons).