Distributed Change Region Detection in Dynamic Evolution of Fragmented Processes

Abstract. Change regions approximate dynamic instance non-migratability through schema based approach. In a distributed process, each node may have a partial view of the structure of the whole process. The distributed structure-fragments may evolve independently at runtime. Established centralized algorithms to compute change regions cannot be directly applied to such a scenario, due to absence of a centralized view. A fully distributed algorithm working on distributed fragments to solve this problem is presented. First, a new centralized change region computation algorithm is developed and proved correct as a basis for the distributed approach. The distributed algorithm is itself presented as a Hierarchical Colored Petri net. An application case is also illustrated

Modeling VP operation: the Diwali festival problem

A new higher-level synchronization problem called Diwali Festival Problem (DFP) is presented. The problem captures the requirements for implementing the VP operation for semaphores outside the operating system kernel in presence of P and V operations, and shared variables with atomic reads and writes.© AC

Anonymous remote computing: a paradigm for parallel programming on interconnected workstations

Parallel computing on interconnected workstations is becoming a viable and attractive proposition due to the rapid growth in speeds of interconnection networks and processors. In the case of workstation clusters, there is always a considerable amount of unused computing capacity available in the network. However, heterogeneity in architectures and operating systems, load variations on machines, variations in machine availability, and failure susceptibility of networks and workstations complicate the situation for the programmer. In this context, new programming paradigms that reduce the burden involved in programming for distribution, load adaptability, heterogeneity and fault tolerance gain importance. This paper identifies the issues involved in parallel computing on a network of workstations. The Anonymous Remote Computing (ARC) paradigm is proposed to address the issues specific to parallel programming on workstation systems. ARC differs from the conventional communicating process model by treating a program as one single entity consisting of several loosely coupled remote instruction blocks instead of treating it as a collection of processes. The ARC approach results in distribution transparency and heterogeneity transparency. At the same time, it provides fault tolerance and load adaptability to parallel programs on workstations. ARC is developed in a two-tiered architecture consisting of high level language constructs and low level ARC primitives. The paper describes an implementation of the ARC kernel supporting ARC primitives.© IEE