This paper focuses on the problem of consistency in distributed data stores. We define strong consistency model which provides a simple semantics for application programmers, but impossible to achieve with availability and partition-tolerance. We also define weaker consistency models including causal and eventual consistency. We review COPS and GentleRain as two causally consistent data stores ...

Weakly consistent data stores have become popular because they enable highly available, scalable distributed applications. However, some data needs strong consistency. For applications that mix accesses to strongly and weakly consistent data, programmers must currently choose between bad performance and possible data corruption. We instead introduce a safe mixed-consistency programming model in...

This paper presents a consistency control protocol destined for groups of cooperative processes located worldwide. We assume that processes cooperate by sharing a replicated object. We consider processes with well-known profiles; however, the actual behaviour of each process could diverge from the profile. The protocol aims at offering a good quality of service to cooperative processes, while g...

Caching frequently accessed data items on the client side is an effective technique to improve the system performance in wireless networks. Due to cache size limitations, cache replacement algorithms are used to find a suitable subset of items for eviction from the cache. Many existing cache replacement algorithms employ a value function of different factors such as time since last access, entr...

Causal consistency offers geo-distributed systems what ought to be a sweet option between the poor performance of strong consistency and the weak guarantees of eventual consistency. Yet, despite its appealing properties, causal consistency has seen limited adoption in industry, where systems have instead been clustering around the two extremes of eventual and strong consistency. We argue that t...

Most weak memory consistency models are incapable of supporting a solution to mutual exclusion using only read and write operations. Processor Consistency–Goodman’s version is an exception. Ahamad et al.[1] showed that Peterson’s mutual exclusion algorithm is correct for PC-G, but Lamport’s bakery algorithm is not. In this paper, we derive a lower bound on the number and type (singleor multi-wr...

DSM-PM2 is a platform for designing, implementing and experimenting multithreaded DSM consistency protocols. It provides a generic toolbox which facilitates protocol design and allows for easy experimentation with alternative protocols for a given consistency model. DSM-PM2 is portable across a wide range of clusters. We illustrate its power with figures obtained for different protocols impleme...

It is well known that causal consistency is more expensive to implement than eventual consistency due to its requirement of dependency tracking and checking for causality. To close the performance gap between the two consistency models, we propose a new protocol that implements causal consistency for both partitioned and replicated data stores. Our protocol trades the visibility latency of upda...