دانلود رایگان ترجمه مقاله الگوریتم قطره های آب هوشمند بر اساس انتخاب و ترکیب خدمات (سال 2012)

الگوریتم قطره های آب هوشمند بر اساس انتخاب و ترکیب خدمات در معماری مبتنی بر خدمات

An Intelligent Water Drops Algorithm Based Service Selection And Composition In Service Oriented Architecture

Abstract

Web services are defined as the pieces of software components, which are distributed over the internet using some standard protocols. With more and more web services become available, QoS is a decisive factor for selecting the most suitable service from a set of candidate services with the identical functionality. Thus the approach about the computation of the QoS is also becoming more important in the service selection. In this paper, we use an algorithm called “Intelligent Water Drops” or IWD algorithm which is inspired from natural science. It is based on the processes that happen in the natural river system. The actions and reactions that take place between the water drops are also considered. The river often chooses an optimal path regarding the conditions of its surroundings to get its ultimate goal, which is often a sea. These ideas are embedded into the web service selection and composition for providing efficient QoS web services. This proposed algorithm provides better computing performance than Particle swarm optimization algorithm (PSO).

1 Introduction

A service is a sequence of activities of more or less intangible nature that normally take place interaction between customer and service system of the service provider, which are provided as solution to the customer problems.[1].A service provider offers the service and a service consumer utilizes the service in service oriented architecture[2].

Web service is typically a web application programming interface that is accessed via HTTP and executed on a remote system, hosting the requested services, composing atomic web services to provide the value added service. Web service composition attracts wide spread concern, because more and more organization provide their business in the form of web service.

The service oriented architecture consists of service provider and service consumer. The service provider provides the service to the user. And the service consumer utilizes service.

1-1 Architecture of Web Services

Figure 1 provides an outline of this web service architecture. The travel planner is comprised of an application server, database server and interface devices. The travel planner can directly communicate with the database via SQL. The travel planner provides customer profile management, that maintains a copy of available providers travel services, items (flights, cars, hotel rooms etc) and package deal information and travel bookings made. Remote travel providers are located using UDDI registries, which provide a description of the remote web services. The travel planner application server communicates via SOAP messages with located provider web services via interface adaptors to obtain copies of travel items, to place bookings and to confirm bookings. The remote providers can send messages back to the travel planner asynchronously., for example Requested booking not longer available, quote about to expire etc[3].A series of tasks are tied together to form a composite web service. Such composition is a challenging task because a number of Web services with the same or similar functions are increasing rapidly. QoS plays a vital role in the problem of selecting the most appropriate web service for composition. It is a measure for how well the composite web service serves the requester. Intelligent water drops (IWD) algorithm can be used to resolve this problem of optimal service selection.