Consistency without concurrency control in large, dynamic systems

Mihai Letia (1, 2) , Nuno Preguiça (3) , Marc Shapiro (1)

1 Regal - Large-Scale Distributed Systems and Applications
2 ENS de Lyon - École normale supérieure de Lyon
3 CITI - Centro de Investigação em Informática e Tecnologias da Informação

Replicas of a commutative replicated data type (CRDT) eventually converge without any complex concurrency control. We validate the design of a non-trivial CRDT, a replicated sequence, with performance measurements in the context of Wikipedia. Furthermore, we discuss how to eliminate a remaining scalability bottleneck: Whereas garbage collection previously required a system-wide consensus, here we propose a flexible two-tier architecture and a protocol for migrating between tiers. We also discuss how the CRDT concept can be generalised, and its limitations.

Mots clés: alg; rep

Domaines: Informatique [cs]

Mihai Letia, Nuno Preguiça, Marc Shapiro. Consistency without concurrency control in large, dynamic systems. LADIS 2009 - 3rd ACM SIGOPS International Workshop on Large Scale Distributed Systems and Middleware, Oct 2009, Big Sky, MT, United States. pp.29--34, ⟨10.1145/1773912.1773921⟩. ⟨hal-01248270⟩