Using Rules and Data Dependencies for the Recovery of Concurrent Processes in a Service-Oriented Environment

This paper presents a recovery algorithm for service execution failure in the context of concurrent process execution. The recovery algorithm was specifically designed to support a rule-based approach to user-defined correctness in execution environments that support a relaxed form of isolation for service execution. Data dependencies are analyzed from data changes that are extracted from database transaction log files and generated as a stream of deltas from Delta-Enabled Grid Services. The deltas are merged by time stamp to create a global schedule of data changes that, together with the process execution context, are used to identify processes that are read and write dependent on failed processes. Process interference rules are used to express semantic conditions that determine if a process that is dependent on a failed process should recover or continue execution. The recovery algorithm integrates a service composition model that supports nested processes, compensation, contingency, and rollback procedures with the data dependency analysis process and rule execution procedure to provide a new approach for addressing consistency among concurrent processes that access shared data. We present the recovery algorithm and also discuss our results with simulation and evaluation of the concurrent process recovery algorithm.