[Tile-serving] Real time tile merging strategy

[sly (sylvain letuffe)]

Hi again,

Is anyone aware of a renderd or tirex option (or other software ?) able to 
real time merge 2 or more (meta-)tiles themself generated by renderd before 
serving it to client ?

The use case is this :
I have a never changing hillshaded/colored + contours background who takes 
ages to generate and a permanently updated osm layer on top of that, much 
faster to generate.

For practical use reasons, I don't want to let the client do the merging of 
PNGs as an overlay and I prefer to send one only tile resulting in the merge 
of png.
While still avoiding to regenate the contours one.

I had the idea to set a proxy in front of mod_tile requesting the 2 tiles, 
merge them, store them, and send them to the client, but that forces me to 
manage a storing backend.

-- 
sly, DWG member since 11/2012
Coordinateur du groupe [ga]
http://wiki.openstreetmap.org/wiki/User:Sletuffe