Non-monotonic Snapshot Isolation: Scalable and Strong Consistency for Geo-replicated Transactional Systems
Reliable Distributed Systems, IEEE Symposium on (2013)
Braga, Portugal Portugal
Sept. 30, 2013 to Oct. 3, 2013
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/SRDS.2013.25
Modern cloud systems are geo-replicated to improve application latency and availability. Transactional consistency is essential for application developers, however, the corresponding concurrency control and commitment protocols are costly in a geo-replicated setting. To minimize this cost, we identify the following essential scalability properties: (i) only replicas updated by a transaction $T$ make steps to execute $T$, (ii) a read-only transaction never waits for concurrent transactions and always commits, (iii) a transaction may read object versions committed after it started, and (iv) two transactions synchronize with each other only if their writes conflict. We present Non-Monotonic Snapshot Isolation (NMSI), the first strong consistency criterion to allow implementations with all four properties. We also present a practical implementation of NMSI called Jessy, which we compare experimentally against a number of well-known criteria. Our measurements show that the latency and throughput of NMSI are comparable to the weakest criterion, read-committed, and between two to fourteen times faster than well-known strong consistencies.
History, Vectors, Scalability, Protocols, Silicon, Synchronization, Ground penetrating radar
Masoud Saeida Ardekani, Pierre Sutra, Marc Shapiro, "Non-monotonic Snapshot Isolation: Scalable and Strong Consistency for Geo-replicated Transactional Systems", Reliable Distributed Systems, IEEE Symposium on, vol. 00, no. , pp. 163-172, 2013, doi:10.1109/SRDS.2013.25