Exploiting IBM Sysplex Services to Automatically FREE a System from the MIMplex

Document ID : KB000054842
Last Modified Date : 14/02/2018
Show Technical Document Details

Description:

Have you ever found yourself in a situation where you have encountered processing delays because you have to rely on manual operator intervention to clear MIM0061 possibly inoperative messages when a system fails for whatever reason and MIM on that system stops accessing the control file? This problem can be resolved using CA MIM's DOWNSYS=AUTOFREE function.

Solution:

The auto FREE feature provides a means to automate the FREE command operation for a CA MIM member on a failed system in a sysplex. This feature is available when the MIMplex is operating at COMPATLEVEL=11.5 or higher. The auto FREE feature functions independently of the MIMplex control file communication methodology.

The auto FREE feature works by reacting to a notification event provided by the XCF/XES operating system component, which describes that a system has been removed from the active sysplex.

The MIMplex can be a subset of a sysplex, or it can be comprised of more than one sysplex. As long as one member of a sysplex survives to provide a system down notification event, the auto FREE feature automatically FREES the removed MIMplex member. A MIMplex member must be a member of a sysplex to be automatically freed with auto FREE. The system down notification event is provided by the XCF/XES operating system component, in a sysplex environment.

In addition to the MIMplex configuration relationship to the sysplex configuration, consider the following regarding the use of the auto FREE feature:

  1. The auto FREE feature is controlled by the SETOPTION MIM DOWNSYS command and can be enabled or disabled on an individual system basis in the MIMplex. DOWNSYS=AUTOFREE needs to be specified on the surviving sysplex member to react to the incoming system down event.

  2. To relate CA MIM system names with MVS system names, the MVS system name, rather than the MVS SMF ID, must be specified on the DEFSYS statement. The MVS system name is defined on the SYSNAME keyword of the IEASYSnn member of the MVS SYS1.PARMLIB data set. The MVS DISPLAY XCF,SYSPLEX,ALL command can be used to list all of the MVS system names in a given sysplex. Alternately, the MVS DISPLAY SYMBOLS command shows the local MVS system name for the &SYSNAME variable name.