Improve caching strategy to avoid outages at peaks

[Mrgaton]

I dont know if already implemented but a cache for a given uri to expire when the next weather update comes would be great to prevent the use of whether queries

[chubin]

There are of course already several levels of caching. The caching policy is not aggressive enough though to handle the peak loads which occur from time to time. We should probably make it adaptive, depending on the current load level, to avoid outages similar to that from yesterday.

[Mrgaton]

You explained better.