IBM GC34-5557-00 manual MQSeries Objects Process Definitions, Channels

MQSeries Objects

Process Definitions

A process definition object defines an application that is to be started in response to a trigger event on an MQSeries queue manager.

A trigger event is a logical combination of conditions that is detected by a queue manager. For example, a trigger event may be generated when the number of messages on a queue reaches a predefined level. This event causes the queue manager to put a trigger message on a specified initiation queue. This trigger message is retrieved by a trigger monitor, a special application that monitors an initiation queue. The trigger monitor then starts up the application program that was specified in the trigger message.

If a queue manager is to use triggering, at least one initiation queue must be defined for that queue manager.

See the MQSeries Application Programming Guide for more information about triggering.

Channels

A channel provides a communication path. There are two types of channel; message channels and MQI channels.

A message channel provides a communication path between two queue managers on the same, or different, platforms. The message channel is used for the transmission of messages from one queue manager to another. It shields the application programs from the complexities of the underlying networking protocols.

A message channel can transmit messages in one direction only. If you require two-way communication between two queue managers, you need two message channels.

An MQI channel connects an MQSeries client to a queue manager on a server machine. It is for the transfer of MQI calls (for example, MQPUT) and responses only and is bidirectional. A channel definition exists for each end of the link. On some platforms, some types of MQI channel can be defined automatically.

For more information about channels see the MQSeries Intercommunication book.

Chapter 1. About MQSeries 5