Obstruction-Free Distributed Transactional Memory

Abstract

Transactional Memory (TM) is a high-level concurrency abstraction that has been investigated in different architectures including distributed systems. In Distributed Software Transactional Memory (DSTM) systems, TM is usually provided either by lock based algorithms, inspired by the ones used in multiprocessor TM, or by using complex agreement protocols. This paper presents a new Distributed Software Transactional Memory architecture, based on obstruction-free algorithms, for the synchronization of distributed applications. We take a new look at obstruction-free algorithms for TM and show that they can be split into client and server actions deriving a distributed version. As a proof of concept we also describe TRMI, an extension to Java’s RMI that provides transactional access to remote objects using the the proposed DSTM architecture. In experiments using a synthetic benchmark that simulates different contention scenarios, TRMI performs better in all scenarios when compared to a simple locking scheme.