Advanced Topics › How You Activate Features of New Releases Dynamically

How You Activate Features of New Releases Dynamically

Normally all systems in a CA MIM complex run at the same release level. However, when new CA MIM releases are announced it can be necessary to run multiple releases of CA MIM.

When a complex is running different releases of CA MIM, COMPATLEVEL controls the activation of selected features. The compatibility level specification permits different releases of CA MIM to coexist in the same complex. COMPATLEVEL controls the activation or suppression of features.

Specify the compatibility level using:

• The MIMINIT COMPATLEVEL statement, which you specify in the MIMINIT member of the MIMPARMS data set.
• The ACTIVATE COMPATLEVEL command, which you issue to change the COMPATLEVEL of the complex.

The MIMINIT COMPATLEVEL statement denotes the level at which the CA MIM complex operates, regardless of the releases on the individual systems that make up the complex. The COMPATLEVEL value must be the same on all systems in the CA MIM complex.

Example 1: Using COMPATLEVEL with active systems

Starting CA MIM r11.9 on a system joining an existing CA MIM r11.8 MIMplex currently running COMPATLEVEL=11.81, assume:

SYSA

Running CA MIM r11.8 at COMPATLEVEL=11.81

SYSB

Running CA MIM r11.8 at COMPATLEVEL=11.81

SYSC

Running CA MIM r11.8 at COMPATLEVEL=11.81

Assuming you want to start CA MIM r11.9 on SYSC, the process would be as follows:

1. Stop the CA MIM r11.8 task on SYSC.
2. Start CA MIM r11.9 task on SYSC with COMPATLEVEL=11.81 specified in MIMINIT.

CA MIM r11.9 on SYSC then joins the existing COMPATLEVEL=11.81 MIMplex (SYSA and SYSB) without any errors.

In order to roll out CA MIM r11.9 to SYSA and SYSB:

1. Stop CA MIM r11.8 task on SYSB.
2. Start CA MIM r11.9 task on SYSB with COMPATLEVEL=11.81 specified in MIMINIT.
3. Stop CA MIM r11.8 task on SYSA.
4. Start CA MIM r11.9 task on SYSA with COMPATLEVEL=11.81 specified in MIMINIT.

CA MIM r11.9 is now running on all three systems at COMPATLEVEL=11.81. To move to COMPATLEVEL=11.9 (without formatting MIM control or checkpoint files which require a global shutdown):

1. Issue the following MIM command on any single system in the MIMplex: ACTIVATE COMPATLEVEL=11.9.
2. Code COMPATLEVEL=11.9 in the MIMINIT member within the MIM parmlib.

Note: COMPATLEVEL=11.9 cannot be specified on any CA MIM statement or command until all systems in the MIMplex are running CA MIM r11.9.

Example 2: Using COMPATLEVEL with inactive systems

In this example:

• CA MIM r11.9 is up and running on SYSA and SYSB and at COMPATLEVEL=11.81.
• SYSC is currently down and FREED.

The ACTIVATE COMPATEVEL command expects all systems that are coded on the DEFSYS statement to be active. Use the FORCE option on the ACTIVATE command.

For example, if you entered the ACTIVATE COMPATLEVEL command without the FORCE option, you would see the following messages:

F MIM,ACTIVATE COMPATLEVEL=11.9
MIM0067 COMMAND ACTIVATE
MIM0628E ACTIVATE command aborted; all defined systems not active      

CA MIM rejected the command, because CA MIM is not active on SYSC. To avoid the rejection, append the FORCE operand:

F MIM,ACTIVATE COMPATLEVEL=(11.9,FORCE)
MIM0067 COMMAND ACTIVATE
MIM0616I ACTIVATE COMPATLEVEL=11.90 has been scheduled 
MIM0619I COMPATLEVEL 11.90 accepted
MIM0620I COMPATLEVEL 11.90 activation in progress
MIM0621I COMPATLEVEL 11.90 activation complete   

The next time CA MIM is started on SYSC, start CA MIM r11.9 with COMPATLEVEL=11.9.

If CA MIM r11.8 on SYSC is started with COMPATLEVEL not equal to 11.9, a U0040 ABEND occurs.