R-Memcached: a consistent cache replication scheme with Memcached

Abstract

Caching is one of the key approaches to improve software system efficiency. And Memcached is a widely-used open source implementation of distributed object caching mechanism. However, Memcached is subject to hotspot problem and single point of failure. In this work, we propose R-Memcached, a scheme to incorporate replication mechanism to Memcached so as to address the aforementioned problems. First, we present how R-Memcached distribute cache replicas to Memcached servers. Second, replication can lead to system inconsistency, and we offer three different protocols to ensure the consistency among cache replicas and provide the adopted read/write strategies in R-Memcached. Finally, we compare the throughput and latency of R-Memcached with some traditional Memcached clients.