[MapProxy] Possible Bug in Cleanup?!

[Oliver Tonnhofer]

Hi Johannes,

On 19.01.2012, at 08:43, Johannes Weskamm wrote:
> I got a problem on a mapproxy-cleanup on an existing cache. It tries to delete non existing tiles, and hangs when it cant find these tiles.
> I have a complete cache and do a cleanup based on polygons from a database (i think this doesnt matter).
> After a while, i get this error (already reproduced this a few times):
> [...]
>  File "/opt/mapproxy/lib/python2.7/site-packages/mapproxy/cache/file.py", line 138, in load_tile_metadata
>    stats = os.lstat(location)
> OSError: [Errno 2] No such file or directory: '/var/mapproxycache/osm_cache_EPSG900913/20/000/035/175/000/044/054.png'
> 
> The process hangs and i stop it with CTRL+C.
> Trying it again seems to work most of the time without errors, what confuses me.
> Wouldnt it be better if mapproxy keeps on cleaning, even if tiles havent been found?
> The version i use is 1.2.1


This looks like a race-condition in the cleanup handling. Do you use custom resolutions or a res_factor != 2?
These errors are now catched in 1.3.x and trunk.

Regards,
Oliver

-- 
Oliver Tonnhofer    | Omniscale GmbH & Co KG    | http://omniscale.de
http://mapproxy.org | https://bitbucket.org/olt | @oltonn