Supervision : Marc SHAPIRO

Co-supervision : SUTRA Pierre

Ensuring Consistency in Partially Replicated Data Stores

In the first part, we study consistency in a transactional systems, and focus on reconciling scalability with strong transactional guarantees. We identify four scalability properties, and show that none of the strong consistency criteria ensure all four. We define a new scalable consistency criterion called Non-Monotonic Snapshot Isolation (NMSI), while is the first that is compatible 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. We also introduce a framework for performing fair comparison among different transactional protocols. Our insight is that a large family of distributed transactional protocols have a common structure, called Deferred Update Replication (DUR). Protocols of the DUR family differ only in behaviors of few generic functions. We present a generic DUR framework, called G-DUR. We implement and compare several transactional protocols using the G-DUR framework. In the second part, we focus on ensuring consistency in non-transactional data stores. We introduce Tuba, a replicated key-value store that dynamically selects replicas in order to maximize the utility delivered to read operations according to a desired consistency defined by the application. In addition, unlike current systems, it automatically reconfigures its set of replicas while respecting application-defined constraints so that it adapts to changes in clients’ locations or request rates.

2011-2016 Publications

• 2016
  • M. Shapiro, M. Saeida Ardekani, G. Petri : “Consistency in 3D”, Int. Conf. on Concurrency Theory (CONCUR) 2016, vol. CONCUR 2016, Int. Conf. on Concurrency Theory (CONCUR) 2016, Québec, Canada, pp. 15 (2016)
  • M. Shapiro, M. Saeida Ardekani, G. Petri : “Consistency in 3D”, (2016)
• 2015
  • D. Malikireddy, M. Saeida Ardekani, M. Shapiro : “Emulating Geo-Replication on Grid5000”, 15 pages (2015)
• 2014
  • M. Saeida Ardekani : “Ensuring Consistency in Partially Replicated Data Stores”, thesis, phd defence 09/16/2014, supervision Shapiro, Marc, co-supervision : Sutra, Pierre (2014)
  • M. Saeida Ardekani, P. Sutra, M. Shapiro : “G-DUR: A Middleware for Assembling, Analyzing, and Improving Transactional Protocols”, Middleware, Bordeaux, France, pp. 12, (IEEE) (2014)
  • M. Shapiro, M. Saeida Ardekani, P. Sutra : “Exploring the spectrum of strongly-consistent transactional protocols”, Workshop on Large-Scale Distributed Systems and Middleware (LADIS), Workshop on Large-Scale Distributed Systems and Middleware (LADIS), Cambridge, United Kingdom (2014)
  • M. Saeida Ardekani, Terry B. Douglas : “A Self-Configurable Geo-Replicated Cloud Storage System”, 11^th USENIX Symposium on Operating Systems Design and Implementation (OSDI 14), Broomfield, CO, United States (2014)
• 2013
  • M. Saeida Ardekani, P. Sutra, M. Shapiro : “Non-Monotonic Snapshot Isolation: scalable and strong consistency for geo-replicated transactional systems”, SRDS 2013 -IEEE 32^nd International Symposium on Reliable Distributed Systems, Braga, Portugal, pp. 163-172, (IEEE Computer Society) (2013)
  • M. Saeida Ardekani, P. Sutra, M. Shapiro, N. Preguiça : “On the Scalability of Snapshot Isolation”, Euro-Par 2013 - 19^th International Conference Parallel Processing, vol. 8097, Lecture Notes in Computer Science, Aachen, Germany, pp. 369-381, (Springer) (2013)
  • M. Saeida Ardekani, P. Sutra, N. Preguiça, M. Shapiro : “Non-Monotonic Snapshot Isolation”, 45 pages (2013)
• 2012
  • M. Saeida Ardekani, M. Zawirski, P. Sutra, M. Shapiro : “The Space Complexity of Transactional Interactive Reads”, HotCDP '12 - 1^st International Workshop on Hot Topics in Cloud Data Processing, Bern, Switzerland, (ACM) (2012)
• 2011
  • M. Saeida Ardekani, P. Sutra, M. Shapiro : “The Impossibility of Ensuring Snapshot Isolation in Genuine Replicated STMs”, WTTM 2011: third workshop on the theory of transactional memory, Roma, Italy (2011)