The Web services architecture is based upon 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. It
includes
- 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.
It includes
- The application program
- The middleware
- The platform on which they run
- The service registry
- A place where service providers publish descriptions of the services
they provide, and where service requesters find them.
The registry is an
optional component of the Web services architecture, as there are many situations
where service requesters and providers can communicate without it. For example,
the organization that provides a service can distribute the service description
directly to the users of the service, using an attachment in an e-mail, or
a download from an FTP site, or even a CD-ROM distribution.
Figure 1. Web service
components and interactions
CICS® provides direct support for implementing
the requester and provider components; you will need additional software to
deploy a service registry in CICS. But because the Web service architecture is platform
independent, you can, if you need a service registry, deploy it on another
platform.
The interactions between the components involve the following operations:
- Bind
- The service requester uses the service description to bind with the service
provider and interact with the Web service implementation.
- Publish
- When a service registry is used, a service provider publishes its description
in a registry so that the requester can find it.
- Find
- When a service registry is used, a service requester finds the service
description in the registry.