Advanced Topics › Command Processing › Target Console Pool › Dynamic Allocation

Dynamic Allocation

CA MIC can dynamically choose and allocate target consoles for use when issuing imported cross-system commands. To enable this function, specify a non-zero value on the SETOPTION MAXCONS command.

The MAXCONS value specifies the maximum number of dynamically allocated target consoles CA MIC acquires throughout the life of the CA MIC address space. Each console is allocated on demand until the MAXCONS limit is reached. Once the limit is reached, CA MIC continually re-assigns the least recently used target console to the current command source.

Note: Target console reassignment can be prevented with a POOL=DEDICATE type linkage.

Note: For more information, see How Linkage Types are Defined in this chapter.

By default, CA MIC allocates extended MCS consoles for all dynamically allocated target consoles. If, however, you have GCMINIT EXTCON=NONE specified to prevent CA MIC from allocating extended MCS consoles, then CA MIC attempts to allocate subsystem consoles for target consoles.

Note: For more information, see the Statement and Command Reference Guide.

Dynamic Allocation of Extended MCS Consoles

Extended MCS consoles provide a programmatic means through a defined interface to issue commands, receive solicited command responses, and receive unsolicited WTO/WTOR/DOM message traffic. IBM has designed the extended console functional interface such that virtually an unlimited number of extended MCS consoles can exist in a single system or in a sysplex environment.

You do not need to specify anything to allow CA MIC to use extended MCS consoles for the dynamic target console pool. However, you can specify the GCMINIT EXTCON statement to customize the usage of extended consoles.

Note: For more information, see the Statement and Command Reference Guide.

There are many advantages to using extended MCS consoles for the target console pool, including the following:

• Alleviates MCS console constraint. MCS consoles, both real and subsystem, are limited in number. For sysplex MCS console maximums, see the current IBM MVS Initialization and Tuning Reference.
• Larger target console pools are possible. This virtually eliminates the possibility of misrouting command responses due to target console reassignment.
• Eliminate contention with other products for consoles. CA MIC defines and allocates its own consoles. No other products have access to these consoles.
• 'SYS1.PARMLIB(CONSOLxx)' modifications are not necessary. Extended MCS consoles are dynamically defined, allocated, and de-allocated. You do not need to do anything to exploit the use of extended consoles.

Dynamic Allocation of Subsystem Consoles

To allow CA MIC to use subsystem consoles for the target console pool, you must specify an adequate number of subsystem consoles (for CA MIC and other products) in SYS1.PARMLIB(CONSOLxx). See How You Define Additional Subsystem-Allocatable Consoles in this chapter.

Note: CA MIC cannot allocate any subsystem consoles already allocated to other subsystems. If all available subsystem-allocatable consoles are allocated to other subsystems, then CA MIC cannot build a target console pool.