Decentralized Communication for Data Dependency Analysis Among Process Execution Agents

Abstract

This paper presents the authors results with the investigation of decentralized data dependency analysis among concurrently executing processes in a service-oriented environment. Distributed Process Execution Agents (PEXAs) are responsible for controlling the execution of processes that are composed of web services. PEXAs are also associated with specific distributed sites for the purpose of capturing data changes that occur at those sites in the context of service executions using Delta-Enabled Grid Services. PEXAs then exchange this information with other PEXAs to dynamically discover data dependencies that can be used to enhance recovery activities for concurrent processes that execute with relaxed isolation properties. This paper outlines the functionality of PEXAs, describing the data structures, algorithms, and communication mechanisms that are used to support decentralized construction of distributed process dependency graphs, demonstrating a more dynamic and intelligent approach to identifying how the failure of one process can potentially affect other concurrently executing processes.