Windows Server AppFabric uses expiration and eviction to maintain the size of its cache and available memory on each cache host.
Eviction is usually dependent upon two levels of thresholds called Watermarks. When the memory usage of cache on a particular host reaches its Low Watermark (LWM) then the expired cache items are taken off from the cache. However, when the memory usage of the cache reaches High Watermark (HWM) then cache items are evicted based on LRU, regardless of their expiry status.
The Windows Server AppFabric cache's eviction is based on a Least Recently Used, or LRU, policy.
This eviction continues until cache usage goes under the lower watermark levels. When cache usage is above watermark levels, subsequent ...