Simulating Web Services Transactions

Abstract

Transactions in a service-oriented environment are very different to traditional transactions. The typical ACID properties are not always appropriate when processing transactions where multiple service providers wish to maintain autonomy and process all requests in a timely manner. Thus, reductions to the ACID properties, such as semantic atomicity and tentative holds, are often used to provide transactions for Web Services. This paper describes a simulator for modelling various Web Services transaction strategies. The simulator is deterministic, allowing the specification of network conditions, provider resources, and client workflows to be kept constant while altering the level of transaction support each provider offers. By modelling transaction flow rather than service flow, this allows true comparison of transaction techniques in various scenarios. The simulator is demonstrated using a validation experiment, and future use outlines how the simulator is being used to test a system where providers offer a dynamic level of transaction support to clients.