MAXXPTCBS

The MAXXPTCBS system initialization parameter specifies the maximum number, in the range 1 through 2000, of open X8 and X9 TCBs that can exist concurrently in the CICS region.

If you do not specify the MAXXPTCBS parameter, the MXT value will be used to set a value for the MAXXPTCBS parameter. For more information on how the value is set from MXT, see Open TCB management.

If you explicitly specify the MAXXPTCBS parameter, or change its value dynamically using EXEC CICS SET DISPATCHER, then you must set it to a correct and optimum value. If you change MXT, however you choose to specify it (as a system initialization parameter, using CEMT, or EXEC CICS SET DISPATCHER, or using CICS Explorer®) you should review your explicit setting for MAXXPTCBS. To revert to allowing CICS® to set this parameter automatically after specifying it explicitly, you would have to reinitialize both the local and global catalogs. Before you reinitialize both the global and local catalogs, see The local catalog.

MAXXPTCBS=number: X8 and X9 are the TCBs that are used to provide support for C and C++ programs compiled with the XPLINK option.

For more information about open TCBs, see Open TCB management.