Associating fan-out and fan-in aggregation flows

Associate the fan-out message flow processing with its corresponding fan-in message flow processing by setting the Aggregate Name property of the AggregateControl and AggregateReply nodes in your aggregation flow to the same value.

If you did not configure this property when you created your fan-in and fan-out flows, you must complete this task.

Before you start:

You must have completed the following tasks:

The Aggregate Name must be contextually unique within a broker. You can have only one AggregateControl node and one AggregateReply node with a particular Aggregate Name, although you can have more than one AggregateControl node with the same Aggregate Name, see Using multiple AggregateControl nodes. Do not deploy a fan-in flow to multiple execution groups on the same broker; results are unpredictable.

You can either create the fan-out and fan-in flows in the same message flow, or in two different message flows. In either case, the two parts of the aggregation are associated when you set the Aggregate Name property.

How you configure your aggregation flow depends on a number of factors:

You can include the fan-out and fan-in flow within the same message flow. However, you might prefer to create two separate flows. The advantages of creating separate fan-out and fan-in flows are:

The following sample shows the use of two flows for aggregation: You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.

To associate the fan-out flow with the fan-in flow:

  1. Switch to the Broker Application Development perspective.
  2. Open the message flow that contains your fan-out flow.
  3. Select the AggregateControl node to open the Properties view, or right-click the node and click Properties to open the Properties dialog. The node properties are displayed.
  4. Set the Aggregate Name property of the AggregateControl node to identify this aggregation. The Aggregate Name that you specify must be contextually unique within a broker.
  5. If you have separate fan-out and fan-in flows:
    1. Press Ctrl-S or click File > Save name on the taskbar menu (where name is the name of this message flow) to save the message flow and validate its configuration.
    2. Open the message flow that contains your fan-in flow.
  6. Select the AggregateControl node to open the Properties view, or right-click the node and click Properties to open the Properties dialog. The node properties are displayed.
  7. Set the Aggregate Name property of the AggregateReply node to the same value that you set for the Aggregate Name property in the corresponding AggregateControl node in the fan-out flow.
  8. Press Ctrl-S or click File > Save name to save the message flow and validate its configuration.
In WebSphere® Message Broker, fan-out and fan-in flows were also associated by sending control messages from the AggregateControl node to the AggregateReply node. This facility is no longer available. For optimum performance, do not connect the AggregateControl and AggregateReply node. However, if you do want to use control messages in your aggregations, and you want to connect these two nodes, see Using control messages in aggregation flows.
Related concepts
Message flows overview
Message flow aggregation
Related tasks
Configuring aggregation flows
Creating the aggregation fan-out flow
Setting timeouts for aggregation
Using multiple AggregateControl nodes
Handling exceptions in aggregation flows
Using control messages in aggregation flows
Related reference
AggregateControl node
AggregateReply node
AggregateRequest node
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Copyright IBM Corporation 1999, 2009Copyright IBM Corporation 1999, 2009.
Last updated : 2009-01-07 15:20:19

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