Monotonic Writes (Session Guarantee) MW
Monotonic writes session guarantee of Terry et al. (PDIS 1994): a replica applies a write from a session only after it has applied all previous writes of that same session, so writes of a session take effect in the order issued. One of the four session guarantees. Brzezinski et al. (2003) proved PRAM = read-your-writes ∧ monotonic reads ∧ monotonic writes (Viotti & Vukolić 2016, Eq. 20), so monotonic writes alone is strictly weaker than PRAM.
Properties
Property vector author-extrapolated — set only where the model’s definition pins the cell down (unknown cells are omitted); cells citing a specific source are marked.
- Reasoning guarantees
- no Coherence
- Atomicity guarantees
- no Multicopy atomic
Ordering relationships
- Strictly weaker than
- PRAM (Pipelined RAM) Consistency — Brzezinski et al. (2003) proved PRAM = read-your-writes ∧ monotonic reads ∧ monotonic writes (Viotti & Vukolić 2016, Eq. 20). PRAM implies monotonic writes while the converse fails, so monotonic writes is strictly weaker than PRAM.
References
- Douglas B. Terry, Alan J. Demers, Karin Petersen, Mike Spreitzer, Marvin Theimer, Brent B. Welch. Session Guarantees for Weakly Consistent Replicated Data. Parallel and Distributed Information Systems (PDIS), 1994. doi:10.1109/PDIS.1994.331722
- Jerzy Brzezinski, Cezary Sobaniec, Dariusz Wawrzyniak. Session Guarantees to Achieve PRAM Consistency of Replicated Shared Objects. Parallel Processing and Applied Mathematics (PPAM), LNCS 3019, 2003. doi:10.1007/978-3-540-24669-5_1
- Paolo Viotti, Marko Vukolić. Consistency in Non-Transactional Distributed Storage Systems. ACM Computing Surveys 49(1), 2016. doi:10.1145/2926965