[Tilecache] Getting frequent 500 Internal Server Error

[David R Robison]

We have multiple client hitting the tile server where all tiles have 
been previously generated and cached. We are seeing frequent "500 
Internal Server Errors" returned from the tile cache, however, when 
requested a second time, the tile returns normally. Here is the 
transaction as reported by LiveHTTPHeaders,

GET 
/tilecache/tilecache.py?LAYERS=basemap&FORMAT=image%2Fgif&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A4326&BBOX=-77.607421875,37.44140625,-77.51953125,37.529296875&WIDTH=256&HEIGHT=256 
HTTP/1.1
Host: xxx.xxx.xxx.xxx
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1) 
Gecko/2008070208 Firefox/3.0.1
Accept: image/png,image/*;q=0.8,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://xxx.xxx.xxx.xxx:8080/OpenCones/app/?wicket:interface=:5::::

HTTP/1.x 500 Internal Server Error
Date: Tue, 09 Sep 2008 13:48:39 GMT
Server: Apache/2.2.6 (Win32) mod_python/3.3.1 Python/2.5.1
Connection: close
Transfer-Encoding: chunked
Content-Type: text/plain

Any ideas on the cause or how best to start debugging this issue?
Thanks, David

-- 

David R Robison
Open Roads Consulting, Inc.
708 S. Battlefield Blvd., Chesapeake, VA 23322
phone: (757) 546-3401
e-mail: drrobison at openroadsconsulting.com
web: http://openroadsconsulting.com
blog: http://therobe.blogspot.com
book: http://www.xulonpress.com/book_detail.php?id=2579