Optimistic replication for internet data services

Abstract

We present a new replication algorithm that supports replication of a large number of objects on a diverse set of nodes. The algorithm allows replica sets to be changed dynamically on a per-object basis. It tolerates most types of failures, including multiple node failures, network partitions, and sudden node retirements. These advantages make the algorithm particularly attractive in large cluster-based data services that experience frequent failures and configuration changes. We prove the correctness of the algorithm and show that its performance is near-optimal.