Dynamic adaptation of geo-replicated CRDTs

Abstract

Conflict-free Replicated Data Types (CRDTs) are high-level data types that can be replicated with minimal coordination among replicas due to its confluent semantics. This property makes CRDTs specially appealing for geo-replicated settings. Di↵erent approaches, such as state transfer and operation forwarding, have been proposed to propagate updates among replicas, with di↵erent tradeo↵s among the amount of network tra c generated and the staleness of local information. This paper proposes and evaluates techniques to automatically adapt a CRDT implementation, such that the best approach is used, based on the application needs (captured by a SLA) and the observed system configuration. Our techniques have been integrated in SwiftCloud, a state of the art geo-replicated store based on CRDTs.

OWebSync: Seamless Synchronization of Distributed Web Clients

“…OWebSync allows replicating any arbitrary subtree of the whole CRDT tree. Hybrid approaches combining operation-based and state-based CRDTs are also possible as demonstrated by Bendy [45]. For data that can tolerate staleness, one can make use of state-based CRDTs, while for data with interactive performance requirements, operation-based CRDTs can be used.…”