AS A SOA GROWS, SOONER OR LATER THE QUESTION OF HOW TO MANAGE ALL THE EXISTING SERVICES arises. How does a consumer find out whether and where a service exists? Where can further information about a service be found, so the consumer can understand it and use it correctly? Dealing with such questions often leads to the concept of a service repository and/or a service registry. This chapter introduces these concepts and discusses when and how to manage services.
Almost every introduction to Web Services introduces three major roles: the role of a service provider, the role of a service consumer (requestor), and the role of a service broker. They interact as shown in the famous Web Services triangle depicted in Figure 17-1.
This triangle recognizes that there is a need for some way to bring providers and consumers together. For this reason, as soon as a provider starts to provide a service, it registers the service at a well-known place (i.e., with the service broker). Then, when a consumer needs a service, the consumer can use the broker to find providers of this service.
In 2000, when Web Services began to take off, a broker called the “Universal Description, Discovery, and Integration Business Registry” (also known as the UDDI Business Registry, or UBR) was announced as the worldwide ...