Web Service Faults

External Web services are called by Service steps in orchestration workflows by sending request SOAP messages. (To the SBM Orchestration Engine, the SBM Application Engine is an external Web service.) Web services also reply with SOAP messages. If an error occurs during the processing of a request, a response SOAP message is returned that contains a SOAP fault. Because orchestration workflows are actually Web services that are invoked by other SBM components, they send and receive SOAP messages as well.

In SBM, the SBM Application Engine invokes a synchronous orchestration workflow with a SOAP message that is sent to the SBM Orchestration Engine. The SBM Orchestration Engine returns a response SOAP message to the SBM Application Engine at the End step.

The SBM Application Engine or an external event invokes an asynchronous orchestration workflow with a request SOAP message that it sends to the Event Manager. The Event Manager relays the message to the SBM Orchestration Engine. For asynchronous orchestration workflows, no response is returned.

During the execution of an orchestration workflow, SOAP messages returned from an external Web service might contain a SOAP fault. The first step in debugging an orchestration workflow using the Common Log Viewer is to look for errors that indicate a SOAP fault. The last error that occurred in the orchestration workflow sequence usually contains the most useful information.

Following are some typical situations that generate error messages for orchestration workflows in the Common Log Viewer:

• You tried to pass an invalid value to the Web service.
• You did not specify the correct path for the WSDL.

• You failed to enter a required expression or you entered an invalid expression, for example, in the Target section of a Calculate step or in the Rule section of a While step.