ConcurrentLinkedHashMap is a concurrent, bounded map for use as an in-memory cache. It is the default caching library in Apache Cassandra and is the reference algorithm for Google Guava CacheBuilder (formally MapMaker).
Caffeine is the Java 8 successor to ConcurrentLinkedHashMap and Guava's cache. Projects should prefer Caffeine and migrate when requiring JDK8 or higher. The previous caching projects are supported in maintenance mode.
- LRU page replacement policy (currently being upgraded to LIRS).
- Equivalent performance to ConcurrentHashMap under load.
- Can bound by the size of the values (e.g. Multimap cache).