A Design And Implementation Of A Web Services Management Frame

With the development of Internet, Web applications based on Internet become more and more popular. The XML-based Web Services come out in order to solve the application-to-application communications and the challenge of the actual distributed computing.Web services are a distributed computing architecture designed and specified to foster cross-platform program-to-program communications. Web services are essentially a messaging architecture that works by enabling loosely coupled applications to work together, simply enabling the passing of messages that contain XML data between disparate systems/operating environments/program languages (cross-platform) . The Web Services architecture is based upon the interactions between three roles: service provider, service registry and service requestor. The interactions involve the publish, find and bind operations. Web Services include three main technologies: SOAP (Simple Object Access Protocol), WSDL (Web Services Description Language) and UDDI (Universal Description, Discovery, and Integration).Web Services are not a real-time software system for connection, which are consistent with Web. Just like session maintenance in HTTP protocol, Web Services need a reasonable management frame. Because SOAP is the center of the current Web Service systems, a reliable management frame should be provided for the object of Web Services called by SOAP protocol. This management frame is used to implement more advanced functions.A Web Service management frame based on Axis is designed and implemented according to the Web Service Architecture Draft and Web Services Life Cycle published by W3C. It is a management frame, which includes a lifecycle management pattern, service state maintenance, service object buffering management and other fundamental support contents of Web Services.Main contributions of our work are as following:We add a Web Services management frame to the management of Web Services object before Axis engine calling Web Services.Because there exist different ways between each type of Web Service object calling, we abstract an agent object which is in charge of different kinds of calling. Agent object makes the calling transparent by object loader module.In order to decrease the number of constructing Web Service objects and overheads of the system introduced by frequently creating, we should apply the buffering technology in the management frame. The object pool of buffering container can achieve this point by saving used objects. Object pool distinguishes the stateful Web Services from stateless Web Services by attaching a key to the Web Services objects. Pool manager answers for the construction and destroy of the object pool.Lifecycle manager module manages the lifecycle of Web Service objects and the transitions among lifecycle states.Web Services management frame can manage the states of Web Services objects, transitions of lifecycle states and buffering by four modules— the service manager(agent object), the object loader, the buffering container and the lifecycle manager.A compared test between the Web Services management frame and Axis has been done with two PCs in the LAN in two different scenarios. The results state that Web Services using buffering technology and lifecycle management have got a better performance and reliability than Axis according to the aspects of throughput, average response time and standard deviation.Further research work includes adding the functions of quality management and transactions of Web Services, optimizing the replacement algorithm of the object pool, doing more tests for more complicated Web Services in any testing environment, and studying the influences to the performance and reliability of the system made by the increasing of users.