Achieving convergent causal consistency and high availability with asynchronous replication

Abstract

Nowadays, distributed data stores have become a fundamental infrastructure for large-scale Internet services, and they usually replicate data partitions to achieve high scalability and availability. To achieve better performance and availability, many Internet services embrace eventual consistency. However, stronger consistency is always desirable for system correctness. Recent studies [1][2] pay more attention to the convergent causal consistency, which is proved to be one of the strongest consistency models that can be achieved together with high availability in the presence of network partitions [3]. Convergent causal consistency couples the virtues of causal consistency and eventual consistency. As a result, convergent causal consistency not only guarantees that clients observe causality throughout, but also ensures that all replicas converge to the same state, which are critical for implementing reasonable application behaviors.