2-layer orchestration mechanism for service composition

Efficient and agile orchestration mechanism for service composition can ensure the scalability and high-efficiency of Web service composition system. Now there are two kinds of orchestration mechanisms: centralization and decentralization, but in fact, both of two have some defects. On the basis of analyzing them, a service community-based 2-layer orchestration mechanism for dynamic service composition is proposed, which adds a community layer to distribute the control logic and corresponding execution load. The design of community engines and concurrent principle and error handling are presented in detail. Analysis results show that 2-layer mechanism improves scalability and availability and it lessens the unnecessary load and complexity to the system in terms of managing and error recovery and fault handling.

I introduction

As a future model for the next generation of Internet computing, Web services have been widely recognized and discussed. They encapsulate information, software or other resources, and make them available over the network via standard interfaces and protocols. Owing to the increasing demand of consumers, single Web service is very difficult to meet consumers' needs. Web service composition^[1] enables businesses to interact with each other and accomplish complex business processes by aggregating the functionality of existing Web services, which has become the focus of research and development. In the WAN environment, composite services own open consumers, and their component services are often autonomous and heterogeneous entities. Consequently, composite services systems need greatly efficient and agile composite orchestration.