Article Preview
TopIntroduction
Working in a fixed humdrum predictable pattern by Organizations in this advance century is being considered outdated. Need is changing as market is turning with consistently high speed. Some renowned technologies like SOA, Cloud Computing, Big Data, Http (Hypertext transfer protocol), SOAP, REST, UDDI, XML etc. are evolving continuously. The need for system and infrastructure over internet emerges. SOA, web services, and Cloud Computing are providing a solution to this problem. These technologies help us in producing interoperable, distributed, parallel computed software systems for both huge enterprise applications or for small businesses. For evolving technologies, like Cloud, the principal constituent is, SOA to deliver IT services. Outer world continuous and rapid changes can be tackled by this. So it is foremost to acknowledge how web services and workflows are scheduled in an IT environment. And also to find out what all are the challenges and issues faced while composing them.
With Adoption of SOA, IT directors and users are capable to address today’s critical challenges of virtualization and at the same time it will provide a solid basis for enterprises to embrace cloud computing for future world. Cloud computing provides significant advantages over current IT architecture (B. Li et al., 2013).
There are two complementing activities in today’s enterprise market: Virtualization and Cloud computing. These technologies are working together and making IT reach new heights. The work will present an overview, style and actuality of service oriented architecture with the objective of laying down challenging issues bothered with miscellaneous traits of assimilating heterogeneous web applications using SOA. A case study will be discussed that will integrate the services using heterogeneous technologies. The proposed work will show web service discovery, selection and composition mechanism.
With the increasing demand, systems are also getting larger and larger than before. Due to this complexity is also increasing with high speed. As we all know that complexity rises exponentially with responsibility and size” (M. Ciavotta et al., 2017) Systems need to be connected with each other. So for the purpose of interconnecting these systems many concepts evolved over the time as per the demands of future. SOA is also a natural evolutionary phase to the procedural, object-oriented (OO), data-centric and component based approaches adopted for the explanatory applications till now (H.-L. Truong and P. Klein, 2020).
There are three types of roles used while developing a web service. It is shown in the Figure 1.
Figure 1. General architectural model of web services (Phu, P. H., 2006)
Discovery, Selection and Composition of Heterogeneous Web Services
The Web services composition life cycle is proposed by (Q. Z. Sheng et al, 2017), as shown in Figure 2. My contribution focuses on three main phases of the life cycle: (i) Service Discovery, (ii) Service Selection and (iii) Service Composition for the Heterogeneous Web services.
For composing a service in an efficient and effective way a case study will be made which is the reflection of the work done by me and this case study will also give an insight about the work in real world scenario (Q. Yu et al., 2015).
A service provider publishes the service on a Web service registry, which accommodates distinct service descriptions, i.e., Web Service Description Language (WSDL) file. To retrieve the services queries has been sent to registry by service consumer. A service consumer queries the registry to retrieve services. Service descriptions indicate competence of services and usually accommodate inputs, outputs, functional and non-functional description (J. Liao et al., 2016). Figure 2 shows the various stages involved in the life cycle of service composition, which are described as follows.
Figure 2. Web service composition architecture (Sheng et al., 2014)