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(TM) /START SUBSYS command, IMS initiates the following resynchronization
process:
- 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.
- The IMS adapter passes the resolution request to WebSphere MQ and reports the result
back to IMS.
- 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.