Dynamic adaptation of geo-replicated CRDTs

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. Different approaches, such as state transfer and operation forwarding, have been proposed to propagate updates among replicas, with different tradeoffs among the amount of network traffic 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.