Connecting from the IMS control region

IMS makes one connection from its control region to each queue manager that uses IMS. IMS must be enabled to make the connection in one of these ways:

• Automatically during either:

  • A cold-start initialization.

  • A warm start of IMS, if the WebSphere MQ connection was active when IMS was shut down.

• In response to the IMS command:

  /START SUBSYS sysid

  
  where sysid is the queue manager name.

  The command can be issued regardless of whether the queue manager is active.

The connection is not actually made until the first MQ API call to the queue manager is made. Until that time, the IMS command /DIS SUBSYS will show the status as 'NOT CONN'.

The order in which you start IMS and the queue manager is not significant.

IMS cannot re-enable the connection to the queue manager automatically if the queue manager is stopped with a STOP QMGR command, the IMS command /STOP SUBSYS, or an abnormal end. Therefore, make the connection by using the IMS command /START SUBSYS.