[Tilecache] High CPU Usage with TileCache on IIS 6

[Christopher Schmidt]

On Tue, Nov 18, 2008 at 04:07:08PM -0500, chris marx wrote:
> Hi,
>  I was wondering if anyone has experience with TileCache and IIS 6 and cpu
> usage. I've been hitting a google map page that make around 30 tile overlay
> requests to tilecache, and even when tilecache is retrieving cached tiles
> (no calls to the WMS (which is on same server) which i validated looking at
> IIS logs), the cpu usage goes up to 90-100%, albiet not for that long (maybe
> a second or 2). Thats only one person hitting one page! Is this an iis
> configuration issue, or should I just start installing apache....

The latter. Each tile requires the Python startup time under IIS/CGI:
you can't expect to serve more than about 15-20 tiles per secnd
depending on your hardware setup under these circumstances.

Specifically, on my relatively fast macbook, python startup is .03s --
which would equate, with 30 tile loads, to your "1-2 seconds" -- 30 *
.03 = 1s of CPU time. 

Regards,
-- 
Christopher Schmidt
MetaCarta