Cluster Comput (2006) 9:237–255 DOI 10.1007/s10586-006-9739-2 Distributed shared arrays: A distributed virtual machine with mobility support for reconfiguration

Abstract Distributed Shared Arrays (DSA) is a distributed virtual machine that supports Java-compliant multithreaded programming with mobility support for system reconfigu-ration in distributed environments. The DSA programming model allows programmers to explicitly control data distri-bution so as to take advantage of the deep memory hierar-chy, while relieving them from error-prone orchestration of communication and synchronization at run-time. The DSA system is developed as an integral component of mobility support middleware for Grid computing so that DSA-based virtual machines can be reconfigured to adapt to the varying resource supplies or demand over the course of a compu-tation. The DSA runtime system also features a directory-based cache coherence protocol in support of replication of user-defined sharing granularity and a communication proxy mechanism for reducing network contention. System recon-figuration is achieved by a DSA service migration mecha-nism, which moves the DSA service and residing compu-tational agents between physical servers for load balancing and fault resilience. We demonstrate the programmability of the model in a number of parallel applications and evaluate its performance by application benchmark programs, in par-ticular, the impact of the coherence granularity and service migration overhead