Putting order in strong eventual consistency

Abstract

Conflict-free replicated data types (CRDTs) aid programmers develop highly available and scalable distributed systems. However, the literature describes only a limited portfolio of conflict-free data types and implementing custom ones requires additional knowledge of replication and consistency techniques. As a result, programmers resort to ad hoc solutions which are error-prone and result in brittle systems. In this paper, we introduce strong eventually consistent replicated objects (SECROs), a general-purpose data type for building available data structures that guarantee strong eventual consistency (SEC) without restrictions on the operations. To evaluate our solution we compare a real-time collaborative text editor built atop SECROs with a state-of-the-art implementation that uses JSON CRDTs. This comparison quantifies various performance aspects. The results show that SECROs are truly general-purpose and memory efficient.