taTHP: A Transaction-Aware Protocol for Web Services Transaction Coordination

Web service is nowadays emerging as a major technology to construct the next generation distributed autonomous computing environment. In this environment, the transaction coordination is like an economic issue that the utilities of transaction coordinator and resource provider are considered at the same time. Tentative hold protocol (THP) is the first attempt that follows this idea. However, its simple policy is short for maximizing the resource utilization in transaction coordination. In this paper, we present a transaction-aware THP (taTHP) to solve this problem. It requires service provider to perceive the transaction context information and play a more active role in dealing with the transaction reservation selection. With the capability of forecasting the will-succeed transactions, taTHP is able to achieve more resource utilization with little negative effect on transaction consistency. Furthermore, a third-party share pattern for the active bi-directional interactions of transaction coordination is also designed to reduce the cost of the "awareness" and a comprehensive comparison is carried out to demonstrate the improvement of the proposed protocol. Finally, it can be concluded from the simulations that taTHP is provided with better efficacy of coordination and more satisfactory utilization of service