Caching is the key to performance, but if done incorrectly is liable to return stale data.
Cohesion uses write-through caches to assure that data is not stale.
Another problem is modifying records in a cluster that may be held in cache on other nodes. Cohesion broadcasts edit events to the other nodes in the cluster so that all nodes can flush their respective caches.
There are several types of caches used by Cohesion:
In memory cache for nearly anything that can be created once.
A multi-level secure record cache.
Out of memory caching using services like Memcached.
Limited use of query caches that can be attributed back to tables to help keep the cache coherent.