Defining and starting a named counter server region

You activate a named counter pool in a z/OS® image by starting up a named counter server region for that pool.

About this task

You can start the server as a started task, started job, or as a batch job. The job or task must invoke the named counter server region program, DFHNCMN, and must run from an APF-authorized library. DFHNCMN is in the CICS® authorized library, CICSTS56.CICS.SDFHAUTH.

Procedure

  1. Specify the DFHNCMN program either in a SYSIN data set defined in the JCL, or in the PARM parameter on the EXEC statement.
  2. Specify the mandatory and optional startup parameters for the DFHNCMN program.
    If you specify a startup parameter in both the SYSIN data set and the PARM parameter, the PARM value overrides the SYSIN value because the z/OS START command can override the PARM value.
    1. You must specify a SYSPRINT DD statement for the print file.
    2. You must specify a SYSIN DD statement for the server parameters.
    3. You must specify the named counter pool name.
    4. You must concatenate the license activation data set (the SDFHLIC library) to the STEPLIB DD statement.
    5. It is recommended that you specify the REGION parameter.
      This parameter ensures that the coupling facility data table server region has enough storage to process the maximum number of named counter requests that can run concurrently.
    6. It is recommended that you specify TIME=NOLIMIT.
      The server task remains in a wait during most normal processing, because server processing is performed under the TCB of the client CICS region. If you omit this parameter, your server job could fail with abend S522 (wait limit exceeded), depending on the JWT value specified in the SMFPRMxx member of SYS1.PARMLIB.
    7. Specify additional parameters as required.
      For example, you might want to alter the warning parameters to modify the thresholds at which warning messages are issued when the structure becomes nearly full.
    Tip: A good way to ensure that all pool-related parameters are consistent across z/OS images is to use the same SYSIN parameter data set, or an identical copy of it, for all servers accessing the same pool, and to specify any parameters that vary between servers in the PARM field.

Example

Figure 1. Sample JCL to start a named counter server address space
//MVSnNC1 JOB  ...
//NCSERVER EXEC PGM=DFHNCMN,REGION=32M,TIME=NOLIMIT   named counter server
//STEPLIB  DD   DSN=CICSTS56.CICS.SDFHAUTH,DISP=SHR    Authorized library
//         DD   DSN=CICSTS56.CICS.SDFHLIC,DISP=SHR     License activation data set
//SYSPRINT DD   SYSOUT=*                              Messages and statistics
//SYSIN    DD   *
POOLNAME=MVSnNC1                                Pool name
/*