[MapProxy] merged layer

[Oliver Tonnhofer]

Hi,

On 07.04.2014, at 15:52, BERÉNYI Attila wrote:
> I'd like to create a 'merged layer' using two caches. The reason is that the update frequency of the two caches are different and I really do not want to re-seed the a merged cache every time an update comes in for single source.
> 
> I have tried something like this:
> test.yaml
> ------------
> [...]
> The merged_layer only shows up in the WMS section, which (more or less) makes sense.
> 
> Is it possible to use TMS/WMTS with merged_layer? (I guess the answer is no.) Maybe with a 'virtual' container?

You need to create another cache with cache_1 and cache_2 as the source:

caches:
  cache_12:
    grids: [global_mercator]
    sources: [cache_1, cache_2]

> Using the WMS service - it seems that the two separate caches are created and populated with tiles - this is exactly what I need. A few questions popped up though:
> What are the performance implications of using WMS compared to TMS?

It should work well if you only have a few concurrent users. But you have to check for yourself if the performance is ok. It does need to decode the tiles, merge them and encode the merged image again.


> Does the WMS service really uses the generated tiles or it will (re)create them on every single request?


It uses the two caches.


Regards,
Oliver

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