What happens when the IMS adapter restarts

For background information, see the WebSphere MQ for z/OS Concepts and Planning Guide.

Whenever the connection to WebSphere MQ is restarted, either following a queue manager restart or an IMS /START SUBSYS command, IMS initiates the following resynchronization process:

1. IMS presents the list of unit of work (UOW) IDs that it believes are in doubt to the WebSphere MQ IMS adapter one at a time with a resolution parameter of Commit or Backout.

2. The IMS adapter passes the resolution request to WebSphere MQ and reports the result back to IMS.

3. Having processed all the IMS resolution requests, the IMS adapter gets from WebSphere MQ a list of all UOWs that WebSphere MQ still holds in doubt that were initiated by the IMS system. These are reported to the IMS master terminal in message CSQQ008I.

Note:

While a UOW is in doubt, any associated WebSphere MQ message is locked by WebSphere MQ and is not available to any application.