[MapProxy] Refresh existing tiles

[Jaak Laineste]

Hello,

I have a mapproxy in front of WMS serving large area (it is OSM Planet). It used mapproxy-seed to pregenerate some tiles to make it respond faster.

Now I refreshed data and need to refresh all the existing tiles (at least in given zoom range) in cache. So how to do it properly? One way would be just deleting everything from cache and regenerating, but this would make service slow after updates, I would rather serve a bit older tiles than give long time to wait for live regeneration.

I ran to set of questions:

 1) I initially tried the same seed.yaml file (with limited area, zoom up to 13) as for initial seeding, just changed refresh_before (time: 2011-12-21T15:35:00) so it should refresh all the tiles, and I run mapproxy-seed. It runs now, but it does not look like it really generates any updated tiles. At least postgres is idle which is not normal for real bulk tile generation.

 2) I want to make sure that all the cached tiles will be refreshed, up to maximum zoom (18), but only existing tiles and for the whole grid (i.e. in global scale). How could I accomplish this? I assume that existing tile indicates that this may be needed soon again, so these should be faster. 

 3) From documentation about refresh_before there is statement "By default, existing tiles will be refreshed.". What does it mean in this context? One way to understand would be that if this parameter is given, then only old tiles are refreshed, no new tiles generated (as I need)? Or is it vice versa? Or is it something else?
 
 4) I have following output for seeder:
...
    Limited to: 21.00000, 57.00000, 27.00000, 60.00000 (EPSG:4326)
    Levels: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
    Overwriting: tiles older than 2011-12-21 15:35:00
[16:00:11]  0   0.00% 2337709.30666, 7760118.67290, 3005626.25142, 8399737.88982 (0 tiles) ETA: N/A
[16:00:11]  1   0.00% 2337709.30666, 7760118.67290, 3005626.25142, 8399737.88982 (0 tiles) ETA: N/A
[16:00:11]  2   0.00% 2337709.30666, 7760118.67290, 3005626.25142, 8399737.88982 (0 tiles) ETA: N/A
...
 Why there is 0 tiles for zooms 0...8? Even if my given pre-seed area is smaller than tile, I want to get also low-zoom tiles pregenerated. You know live generation of low zoom tiles is very slow, especially with whole planet database.

Regards,
Jaak
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapproxy/attachments/20111221/df85f57a/attachment.html