Bucket4j is designed to be low latency solution, as result it processes any rate-limiting request via one network round-trip, in same time Memcached supports only compare and swap paradigm that can lead to many round-trips in case of high contention, so Bucket4j will never support Memcached. It is better to choose one of JCache provider(in context of rate-limiting) instead of Memcached, like Hazelcast or Apache Ignite, because they are true distributed computation solutions in opposite to Memcached which is just cache solution.