Replicated data types that unify eventual consistency and observable atomic consistency

Cloud Types for Eventual Consistency

Mobile devices commonly access shared data stored on a server. To ensure responsiveness, many applications maintain local replicas of the shared data that remain instantly accessible even if the server is slow or temporarily unavailable. Despite its apparent simplicity and commonality, this scenario can be surprisingly challenging. In particular, a correct and reliable implementation of the com...

Observable atomic consistency for CvRDTs

The development of distributed systems requires developers to balance the need for consistency, availability, and partition tolerance. The recently proposed Global Sequence Protocol (GSP) provides an abstract, high-level programming model for asynchronous commands between client and server, which provides a foundation for implementations as well as consistency guarantees. In order to enable off...

Eventual Consistency

In a replicated database, the consistency level defines whether and how the values of the replicas of a logical object may diverge in the presence of updates. Eventual consistency is the weakest consistency level that guarantees convergence. Informally, it requires that all replicas of an object will eventually reach the same, correct, final value, assuming that no new updates are submitted to ...

Consistency Models for Replicated Data

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...

Consistency Maintenance using UNIFY