[MapProxy] concurrent seed workers on windows

[Oliver Tonnhofer]

Hi,


> On 22.12.2015, at 09:14, Brunner Tobias (GEO) <Tobias.Brunner at zuerich.ch> wrote:
> […] 
> I suspect this may have something to do with the python-multiprocessing on windows…?
> Is this a known issue on windows and are there any workarounds?

The way mapproxy-seed is implemented is incompatible with python-multiprocessing on Windows. It therefore uses threading on Windows. Threading in Python is limited in how things can run in parallel (search for GIL if you are interested). More recent Pillow versions are able to "release the GIL” when encoding images, so it should be able to use more than one CPU.

Which version of Pillow/PIL do you use?


> Systems:
> Mapproxy-Windows-VM: 8 cores, 12 GB of ram, windows server 2012 r2, python 2.7 (osgeo4w)
> Mapproxy-linux-VM: 8 cores, 12 gb of ram, redhat

If you have the option: go with linux. 


Regards,
Oliver

-- 
Oliver Tonnhofer  | Omniscale GmbH & Co KG  | http://omniscale.com
OpenStreetMap WMS and tile services         | http://maps.omniscale.com