A message collection is a single message that contains multiple messages derived from one or more sources. You can use a Collector node to group together messages from one or more sources into a message collection, so that they can be processed together by downstream nodes.
Information about the state of in-flight messages is held on system queues that are controlled by IBM® MQ, so you must install WebSphere MQ on the same computer as your integration server if you want to use event driven processing.
The system queues that hold the state information are owned by the queue manager that is specified on the integration server. You associate a queue manager with the integration server by specifying the queue manager name on the defaultQueueManager property in the server.conf.yaml configuration file; for more information, see Configuring an integration server by using the server.conf.yaml file.
You must create the system queues by running a script command, as described in Creating the default system queues on a WebSphere MQ queue manager.
For more information about using WebSphere MQ with IBM App Connect Enterprise, see Installing IBM MQ.
The topics in this section describe how message collection works, and explain how you can configure your message flow to process message collections.