CRDTs: Consistency without concurrency control

TL;DR

This paper introduces Conflict-free Replicated Data Types (CRDTs), which enable eventual consistency in distributed systems without complex concurrency control, demonstrated through a novel shared edit buffer called Treedoc.

Contribution

It presents the design, implementation, and analysis of Treedoc, a non-trivial CRDT, and discusses the generalization and limitations of the CRDT concept.

Findings

Treedoc converges without complex concurrency control.

CRDTs can be generalized to various data types.

Performance analysis shows Treedoc's efficiency.

Abstract

A CRDT is a data type whose operations commute when they are concurrent. Replicas of a CRDT eventually converge without any complex concurrency control. As an existence proof, we exhibit a non-trivial CRDT: a shared edit buffer called Treedoc. We outline the design, implementation and performance of Treedoc. We discuss how the CRDT concept can be generalised, and its limitations.