Usage notes

  1. If an MQDISC call is issued when the connection still has objects open under that connection, the queue manager closes those objects, with the close options set to MQCO_NONE.
  2. If the application ends with uncommitted changes in a unit of work, the disposition of those changes depends on how the application ends:
    1. If the application issues the MQDISC call before ending:
      • For a queue-manager-coordinated unit of work, the queue manager issues the MQCMIT call on behalf of the application. The unit of work is committed if possible, and backed out if not.

        On z/OS, batch programs (including IMS(TM) batch DL/1 programs) are like this.

      • For an externally-coordinated unit of work, there is no change in the status of the unit of work; however, the queue manager typically indicates that the unit of work must be committed when asked by the unit-of-work coordinator.

        On z/OS, CICS, IMS (other than batch DL/1 programs), and RRS applications are like this.

    2. If the application ends normally but without issuing the MQDISC call, the action taken depends on the environment:
      • On z/OS, the actions described under (a) above occur.
      • In all other cases, the actions described under (c) below occur.
      Because of the differences between environments, ensure that applications that you want to port commit or back out the unit of work before they end.
    3. If the application ends abnormally without issuing the MQDISC call, the unit of work is backed out.
  3. On z/OS, the following points apply:
  4. On i5/OS, applications running in compatibility mode do not have to issue this call; see the MQCONN call for more details.