Optimizations

[ale-rt]

I am reporting quickly what I found.
When I finished my assessment I will make this issue look better!

Replace

if request and rcachekey in list(request.keys()):
     return request[rcachekey]
return VALUE_NOT_CACHED

with something like:

return (request or {}).get(rcachekey, VALUE_NOT_CACHED)

or at list replace rcachekey in list(request.keys()) with rcachekey in request.

Also this does not work for subrequests: I see multiple connections for every tile I use and for the diazo compilation.
Caching the connection in memcached might be better.
BTW I do not know if I have the plugin improperly configured ;)

[jensens]

subrequests indeed. we should get the root-parent first in a non expensive way

[ale-rt]

Thanks @jensens for moving this forward