SCA outbound message flows are message flows that call a service component on WebSphere® Process Server. By using an SCARequest node, or a pair of SCAAsyncRequest and SCAAsyncResponse nodes, you can call a service component in WebSphere Process Server.
The binding type derived from the SCA definition can be either Web Service or MQ; if an MQ binding is specified in the SCA definition, WebSphere MQ must be available to process the messages, so you must ensure that WebSphere MQ is installed on the same computer as your integration node. WebSphere MQ is not provided as part of the IBM Integration Bus installation package, but your license for IBM Integration Bus entitles you to install and use WebSphere MQ. For more information about using WebSphere MQ with IBM Integration Bus, see Installing WebSphere MQ.
If the request is request-response, the node sends the request, then blocks until it receives a response, or the timeout period is exceeded. If the timeout period is exceeded, the message received on the input terminal of the SCARequest is propagated to the Failure terminal.
If the request is one-way, the node sends a request only. The message received on the input terminal of the SCARequest node is propagated to the Out terminal.
When IBM Integration Bus needs to make an asynchronous call to a service component that is provided by WebSphere Process Server, use a message flow, or flows, that contains a pair of SCAAsyncRequest and SCAAsyncResponse nodes. The SCAAsyncRequest node sends a request to a service component running on WebSphere Process Server. The SCAAsyncResponse node receives the response from WebSphere Process Server to a previously made asynchronous request from an SCAAsyncRequest node. Responses are correlated against the original requests.
The SCAAsyncRequest node requests sends a request to a service component running on WebSphere Process Server. The SCAAsyncResponse node receives the response from WebSphere Process Server to a previously made asynchronous request from an SCAAsyncRequest node. Responses are correlated against the original requests.
The SCAAsyncResponse node can be in the same message flow as the SCAAsyncRequest node which makes the request, or it can be in a separate message flow; it must, however, be in the same integration server as the SCAAsyncRequest node.