Towards verifying eventually consistent applications

Abstract

Modern cloud and distributed systems depend heavily on replication of large-scale databases to guarantee properties like high availability, scalability and fault tolerance. These replicas are maintained in geographically distant locations to be able to serve clients from different regions without any loss of performance. Ideally, these systems require to achieve immediate availability while preserving strong consistency in the presence of network partitions. But unfortunately, the CAP theorem [1] proves that it is impossible to have all these properties together in a distributed system. For this reason, architects of current distributed systems frequently omit strong consistency guarantees in favor of weaker forms of consistency, commonly called eventual consistency[2].