AggregateRequest node
Use the AggregateRequest node to record the fact that request messages have been sent. This node also collects information that helps the AggregateReply node to construct the compound response message.
Information about the state of in-flight messages is held on storage queues that are controlled by IBM® MQ. If you are using aggregation on an integration server that is managed by an integration node, you must install IBM MQ on the same computer as your integration node in order to use the capabilities that are provided by the AggregateRequest node. The storage queues that hold the state information are owned by the queue manager that is associated with the integration node.
If you are using aggregation on an independent integration server, you can use a remote default queue manager to control the system queues, without the need to install IBM MQ on the same machine as the integration server. Interactions between an independent integration server and IBM MQ can use a client connection to a remote queue manager, by using a default policy setting. For more information about using a remote default queue manager, see Using a remote default queue manager and Configuring an integration server to use a remote default queue manager.
For more information about the queues that are required by the AggregateControl node, see Configuring the storage of events for aggregation nodes.
This topic contains the following sections:
Purpose
Aggregation is an extension of the request/reply application model. It combines the generation and fan-out of a number of related requests with the fan-in of the corresponding replies, and compiles those replies into a single aggregated reply message.
- The AggregateControl node marks the beginning of a fan-out of requests that are part of an aggregation. It sends a control message that is used by the AggregateReply node to match the different requests that have been made. The information that is propagated from the Control terminal includes the integration node identifier, the aggregate name property, and the timeout property. The aggregation information that is added to the message Environment by the AggregateControl node must not be changed.
- The AggregateRequest node records the fact that the request messages have been sent. It also collects information that helps the AggregateReply node to construct the aggregated reply message. The information that is added to the message Environment by the AggregateRequest node must be preserved, otherwise the aggregation fails.
- The AggregateReply node marks the end of an aggregation fan-in. It collects replies and combines them into a single aggregated reply message.
The AggregateRequest node is contained in the Routing drawer of the palette, and is represented in the IBM App Connect Enterprise Toolkit by the following icon:
Terminals and properties
When you have put an instance of the AggregateRequest node into a message flow, you can configure it; see Configuring a message flow node. The properties of the node are displayed in the Properties view. All mandatory properties for which you must enter a value (those that do not have a default value defined) are marked with an asterisk.
The AggregateRequest node terminals are described in the following table.
| Terminal | Description |
|---|---|
| In | The input terminal that accepts messages sent as part of an aggregate request. |
| Out | The output terminal to which the input message is routed when processing completes successfully. |
The following tables describe the node properties. The column headed M indicates whether the property is mandatory (marked with an asterisk if you must enter a value when no default is defined); the column headed C indicates whether the property is configurable (you can change the value when you add the message flow to the BAR file to deploy it).
The AggregateRequest node Description properties are described in the following table.
| Property | M | C | Default | Description |
|---|---|---|---|---|
| Node name | No | No | The node type (AggregateRequest) | The name of the node |
| Short Description | No | No | A brief description of the node. | |
| Long Description | No | No | Text that describes the purpose of the node in the message flow. |
The AggregateRequest node Basic property is described in the following table.
| Property | M | C | Default | Description |
|---|---|---|---|---|
| Folder Name | Yes | No | The name that is used as a folder in the AggregateReply node's compound message to store the reply to this request. You must enter a value for this property, but the value does not need to be unique. |
| Property | M | C | Default | Description |
|---|---|---|---|---|
| Events | No | No | None | Events that you have defined for the node are displayed on this tab. By
default, no monitoring events are defined on any node in a message flow. Use
Add, Edit, and Delete to
create, change or delete monitoring events for the node. You can enable and disable events that are shown here by selecting or clearing the Enabled check box. |