Defining and starting a coupling facility data table server
region
You activate a coupling facility data table pool in an MVS™ image by starting up a coupling facility data table 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 coupling facility
data table server region program, DFHCFMN, from an APF-authorized
library. DFHCFMN is in the CICS® authorized library, CICSTS54.CICS.SDFHAUTH.
Procedure
Specify the DFHCFMN program either in a SYSIN data set
defined in the JCL, or in the PARM parameter
on the EXEC statement.
Specify the mandatory and optional startup parameters for
the DFHCFMN 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 MVS START command can override the PARM value.
You must specify a SYSPRINT DD statement for the print
file.
You must specify a SYSIN DD statement for the server
parameters.
You must specify the TS pool name.
You must concatenate the license activation data set
(the SDFHLIC library) to the STEPLIB DD statement.
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 data table requests that can run concurrently.
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.
Specify additional parameters as required.
For example, you might want to control the maximum number of queues
that are to be supported in the pool and the number of buffers the
server is to allocate.
Results
Tip: The easiest way to ensure that all pool-related
parameters are consistent across MVS 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 in the PARM field any parameters that
vary between servers.