Hi, I've just committed preliminary attempt to implement LIRS. There does not seem to be serious degradation in terms of performance when it comes to get/remove commands in comparison with LRU enabled BufferedConcurrentHashMap. However, put command is about three times slower than in LRU; put in LIRS is as fast as put command of a single lock synchronized HashMap. Looking for enthusiasts willing to help out with some code review :) Regards, Vladimir