Service stub overview

Service stubs are simulations of an actual service, which can be used to functionally replace the service in a test environment. A stub server replaces the actual application server.

From the point of view of the client application, the service stub looks identical to the actual service that it simulates. To use a service stub in replacement of the actual service, you must be able to replace the URL of the original service in the client application with the URL of the stub server.

Important: For version 8.7 and later, you cannot use the schedule option of IBM® Rational® Performance Tester to deploy stub servers remotely. If you have already deployed stub servers remotely, you must install IBM® Rational® Service Tester for SOA Quality or Rational® Performance Tester on those computers and then deploy the stub servers locally.

Use case examples

There are several cases where it can be useful to deploy a stub services instead of using the actual services for your tests:
  • If you are testing a local service that uses data from another remote service, you might need to inject specific content to the service under test from the remote service. You can simulate the remote service with a service stub to ensure that the local service responds properly to some specific input.
  • Some commercial services charge users for each call. If you are testing such a service, you can develop and debug your test against a stub service, which is based on the WSDL of the actual service, without being charged by the commercial service.
  • During integration of a large application involving multiple clients and services, some services might not yet be operational, although their WSDL specifications are available. You can simulate the missing services with service stubs, which will allow you to proceed with the integration work.

Service stub architecture

You create a service stub by providing an existing WSDL specification. The service stub is generated with the exact same ports and bindings as the original service so that it can be addressed with exactly the same interface. Each operation in the service returns a default response of the type defined by the WSDL.

You can edit the service stub in the stub editor to change the default response or to create conditional responses that simulate the actual responses of the original service.

When you have finished editing the service stub, you can deploy it on a local stub server, which runs in the workbench. The stub server simulates an actual application server and can host multiple service stubs. You control the stub server from the stub monitor view.

Finally, to use the service stub instead of the original service, you change the URL used by the client application to point to the local stub server instead of the original application server. This URL, as well as the WSDL of the service stub, is provided in the stub monitor view.