[Tilecache] tilecache_seed dies at a specific tile - how can I skip it?

[Christopher Schmidt]

On Mon, Oct 26, 2009 at 09:41:22AM +0200, Adrian Popa wrote:
> Hello everyone,
> 
> I'm getting an error while trying to cache offline parts of my map. The 
> caching process runs fine until it hits a particular tile (my guess is 
> it's tile 9143) - when the process dies (after a timeout of 2 minutes).
> 
> Here are samples of the output:
> 
> [root at terra utilities]# python /var/www/html/tilecache/tilecache_seed.py 
> rtc_base 1 10 --bbox 
> 2255332.8831578,5336357.2739115,3306188.8761,6183726.4985628
> ...
> 07 (004621, 005229) = (2568284.1491 5542601.7932 2573176.1189 
> 5547493.7630) [0.0003s : 2391.549/s] 9137/37195
>   File "/usr/lib/python2.4/urllib2.py", line 480, in http_error_default
>     raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
> urllib2.HTTPError: HTTP Error 500: Internal Server Error
> 
> Here is what httpd error_log says:
> [Mon Oct 26 09:23:13 2009] [warn] [client 127.0.0.1] Timeout waiting for 
> output from CGI script /var/www/cgi-bin/mapserv
> [Mon Oct 26 09:23:13 2009] [error] [client 127.0.0.1] Premature end of 
> script headers: mapserv
> [Mon Oct 26 09:25:13 2009] [warn] [client 127.0.0.1] Timeout waiting for 
> output from CGI script /var/www/cgi-bin/mapserv
> 
> 
> If I try with the --reverse parameter, the same thing happens after a 
> while, but at a different tile.
> 
> I have two questions:
> 1. Can I convince tilecache to skip the tiles it can't render, instead 
> of dying?

Not build in, but you can certainly modify the client to catch errors and 
keep going.

> 2. What would be the necessary steps I need to take to troubleshoot this 
> problem? (I am generating this cache from a mapserver which is getting 
> its data from shapefiles).

Look in the apache logs for the mapserver, look at what the URL is, 
and send it to the mapserver. See if it fails in the same way. If so, it's 
a mapserver 'issue' (quotes because it may simply be taking too long to do
this tile, and the actual issue is that you need to bump up your apache
timeout), and can be treated externally to TileCache.

-- Chris

> 
> Thanks,
> Adrian
> 
> _______________________________________________
> Tilecache mailing list
> Tilecache at openlayers.org
> http://openlayers.org/mailman/listinfo/tilecache

-- 
Christopher Schmidt
MetaCarta