There was a subtle change of eviction semantics starting with 4.1 where only immortal entries are considered as eviction candidates. By default all entries are immortal, that is, their expiration and lifespan are -1. As soon as mortal entries are used (expiration !=-1 || lifespan !=-1) they are not subject to eviction policies and container size can grow above limit specified in maxEntries.

This policy is confusing and it does not make a lot of sense. All candidates, both mortal and immortal should be considered as eviction candidates and as such subject to eviction.