SOAP web services architecture

The SOAP web services architecture is based on interactions between three components: a service provider, a service requester, and an optional service registry.

The service provider
The collection of software that provides a web service.
  • The application program
  • The middleware
  • The platform on which they run
The service requester
The collection of software that is responsible for requesting a web service from a service provider.
  • The application program
  • The middleware
  • The platform on which they run
The service registry
The service registry is a central location where service providers can publish their service descriptions and where service requesters can find those service descriptions.

The registry is an optional component of the web services architecture because service requesters and providers can communicate without it in many situations. For example, the organization that provides a service can distribute the service description directly to the users of the service in a number of ways, including offering the service as a download from an FTP site.

Using a service registry offers a number of advantages to both the requester and provider; for example, using the IBM® WebSphere® Service Registry and Repository (WSRR) can help the requester to find services more quickly and can help the provider to enforce version control of the services being offered.

CICS® provides direct support for implementing service requester and service provider components. However, you need additional software to deploy a service registry in CICS. If you use the IBM WebSphere Service Registry and Repository (WSRR), CICS provides support for WSRR through the web services assistant. Alternatively, you can deploy a service registry on another platform.

Interactions between a service provider, a service requester, and, a service registry

The interactions between the service provider, service requester, and service registry involve the following operations:
Publish
When a service registry is used, a service provider publishes its service description in a service registry for the service requester to find.
Find
When a service registry is used, a service requester finds the service description in the registry.
Bind
The service requester uses the service description to bind with the service provider and interact with the web service implementation.
Figure 1. web services components and interactions
The interactions between the web service components. These interactions are described in the text.