Problem

During deployment, you see an error like this:

ERROR  01/Jan/2019:00:00:00.000 Disk persistence is on and eviction policy is not LFU

Resolution

To get rid of this error without a change in behavior, set the affected caches to LFU (Least Frequently Used).

NOTE: Be careful not to confuse LFU with LRU (Least Recently Used).

This error indicates that invalid ehCache settings are in use. This was always an incorrect setting for ehCache, but it was silently ignored until 7.5.3 SP10 because ehCache assumes LFU eviction when persist to disk is on and silently ignores attempts to configure other cache eviction policies.

This is not a behavior change, because the invalid config was never used by ehCache. Because of that, the only ways to get rid of the error message are either to set the eviction policy to LFU, or to disable the persist to disk option. Setting the policy to LFU is the better option because it will not change the behavior from what you have already been running with. However, if you truly desire a different cache eviction policy, you will have to disable persist to disk and test the changes because it will change behavior in that case.