Non-uniform Replication

TL;DR

This paper introduces non-uniform replication, a novel approach where replicas store only part of the data but can still answer all queries, improving efficiency in distributed systems.

Contribution

It proposes the concept of non-uniform replication and demonstrates its application to eventual consistency and conflict-free data types, with practical data type solutions.

Findings

More efficient than traditional replication in storage and bandwidth

Addresses high latency issues in geo-replicated systems

Provides new data types for non-uniform replication

Abstract

Replication is a key technique in the design of efficient and reliable distributed systems. As information grows, it becomes difficult or even impossible to store all information at every replica. A common approach to deal with this problem is to rely on partial replication, where each replica maintains only a part of the total system information. As a consequence, a remote replica might need to be contacted for computing the reply to some given query, which leads to high latency costs particularly in geo-replicated settings. In this work, we introduce the concept of non-uniform replication, where each replica stores only part of the information, but where all replicas store enough information to answer every query. We apply this concept to eventual consistency and conflict-free replicated data types. We show that this model can address useful problems and present two data types that solve such problems. Our evaluation shows that non-uniform replication is more efficient than traditional replication, using less storage space and network bandwidth.