There are many different replica control techniques, used in different research communities. To understand when one replica management algorithm can be replaced by another, we need to describe more abstractly the consistency model, which captures the set of properties that an algorithm provides, and on which the clients rely (whether the clients are people or other programs). In this chapter we...

When distributed clients query or update shared data, eventual consistency can provide better availability than strong consistency models. However, programming and implementing such systems can be difficult unless we establish a reasonable consistency model, i.e. some minimal guarantees that programmers can understand and systems can provide effectively. To this end, we propose a novel consiste...

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...

UML is widely accepted and extensively used in software modeling. However, using different diagrams to model different aspects of a system brings the risk of inconsistency among diagrams. In this paper, we investigate an approach to check the consistency between the sequence diagrams and statechart diagrams using the SPIN model checker. To deal with the hierarchy structure of statechart diagram...

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...