254 Using IBM WebSphere Message Broker as an ESB with WebSphere Process Server
The request properties (Figure 8-31) mark this message as a request message
requiring a response. The reply-to queue for the response is the input queue for
the FindSuppliersAggFanIn.msgflow message flow, which aggregates the
responses from the two suppliers.
Figure 8-31 Request properties of the AggRequestToSupplier1 node
The AggRequestToSupplier2 MQOutput node is identical to the
AggRequestToSupplier1 node with the exception of the queue name. A new
message ID is set and the reply-to queue is also set to
SC4.FINDSUPPLIERS.AGG.FANIN. Figure 8-32 shows the basic properties.
Figure 8-32 Basic properties of the AggRequestToSupplier2 node
The AggregateRequest node serves the following purposes:
It stores internal information regarding the request that was sent to the output
It assigns the response to this message to a particular folder within the
message tree of the aggregated message in the
FindSuppliersAggFanIn.msgflow. This helps the developer identify how to
distinguish the response to this aggregate request from others by storing the
response message in the named folder within the message tree.
Chapter 8. Scenario: Aggregation 255
Figure 8-33 shows the basic properties of the AggregateRequest1 node.
Figure 8-33 Basic properties of the AggregateRequest1 node
The AggregateRequest2 node is similar to the AggregateRequest1 node, but
specifies a different folder for the response. Figure 8-34 shows the properties of
the AggregateRequest2 node.
Figure 8-34 Basic properties of the AggregateRequest2 node
Message flow: At the end of this flow, the aggregated messages are sent to
the services. The responses from the services are placed on the
SC4.FINDSUPPLIERS.AGG.FANIN queue. The next message flow in the
aggregation process is the FindSuppliersAggFanIn message flow.
In our test lab, we used message flows to emulate the supplier enterprise
information systems. You can see these message flows in 8.5.7, “Supplier1
message flow” on page 266, and 8.5.8, “Supplier2 message flow” on