2.1. Service-oriented architecture
Service-oriented architecture is a software structure where services are made available to the users via computer network by using communication protocols. In addition to service-oriented technology, an essential part of service-oriented architecture also includes regulations, practices and frameworks, which ensure the provision and consumption of necessary services. When using service-oriented architecture, there are always providers and users of services. Services are mainly web services.
Web service is a method called via web. Web service interface is described in a machine-readable format. Other systems can communicate with the web service with messages as described. Usually HTTP is used for data exchange and XML for serialisation. An advantage of using web services lies in the fact that realisation details of services are abstracted and the use of services takes place through standardised interfaces.Use of a service directory facilitates the search and use of web services. Provider of the service describes the service interface and publishes a service description in a machine-readable format in the service directory. User of the service searches for a description of a suitable service from the service directory and submits a request for the service based on found information (Figure 10).
Figure 10 Service-oriented architecture
A common way for the realisation of service-oriented architecture is a description of services in the WSDL format, using SOAP protocol for data exchange, and publishing service descriptions with service level requirements (Service Level Agreements – SLA) in the service directory.