Advanced Program-to-Program Communication (APPC) is started with the APPC active conversation threshold indicated for one address space. This message is issued to hardcopy only.

For each APPC active conversation on the system, APPC reserves a certain amount of system storage. A runaway transaction program, which creates many conversations but never deallocates them, could potentially exhaust the fixed amount of system storage that APPC has obtained. To inform the installation of such a program and optionally to prevent any conversation from being started in the affected address space, APPC allows the installation to specify a threshold that will cause notification of such a problem.

You can define the APPC active conversation threshold on the CONVMAX subparameter of the PARM parameter of the EXEC statement in the APPC member of SYS1.PROCLIB. The CONVMAX value is a 1- to 5-digit number indicating the maximum APPC active conversations a single address space can have before APPC intervenes and takes actions. See the CMACTION parameter description to determine what actions APPC takes when this limit has been reached.

The minimum possible value is CONVMAX=100. If you specify a value between 1 and 99 on the CONVMAX parameter, the system sets the maximum APPC conversions threshold to 100.

The maximum possible value is CONVMAX=20000. If you do not specify a value for CONVMAX, the system uses a default of 2000.

If you specify a value greater than 20000, the system sets the maximum APPC active conversations threshold to 20000.

If you specify a value of 0 (zero) then the system will not monitor the total number of conversations for an address space, regardless of the quantity.