Role of the client channel definition table

The client channel definition table is created when you define the first of the connections between a WebSphere MQ client and a server. See Defining MQI channels for more information about what you have to define and how you do it.

Note:
The same file can be used by more than one WebSphere MQ client. You change the name and location of this file using the MQCHLLIB and MQCHLTAB WebSphere MQ environment variables. See Chapter 10, Using WebSphere MQ environment variables for information about environment variables.

 

Multiple queue managers

You might choose to define connections to more than one server machine because:

  • You need a backup system.

  • You want to be able to move your queue managers without changing any application code.

  • You need to access multiple queue managers, and this requires the least resource.

Define your client-connection and server-connection channels on one queue manager only, including those channels that connect to a second or third queue manager. Do not define them on two queue managers and then try to merge the two client channel definition tables; this cannot be done. Only one client channel definition table can be accessed by the client.

 

Queue-sharing groups

You can connect your application to a queue manager that is part of a queue-sharing group. This can be done by using the queue-sharing group name instead of the queue manager name on the MQCONN or MQCONNX call.

The client channel definition should use the queue sharing group generic interface to connect to an available queue manager in the group. For more information, see Connecting to the generic interface. A check is made to ensure that the queue manager the listener connects to is a member of the queue sharing group.

For more information on shared queues, see the see the WebSphere MQ for z/OS Concepts and Planning Guide book, and the WebSphere MQ Intercommunication book.

 

WebSphere is a trademark of the IBM Corporation in the United States, other countries, or both.

 

IBM is a trademark of the IBM Corporation in the United States, other countries, or both.