Specifying CICS options through the HFZOPTS DDname

To avoid the need to recycle CICSĀ® in case compiler listing or side file data sets change, specify these via the DataSets option in a user options file that is pointed to by the HFZOPTS DDname. For details, refer to DataSets and User options file HFZOPTS.

It is also better to use the HFZOPTS DDname pointing to a data set and containing:
DataSets(HFZHIST(history-file-dsn))
than to use the following statement in the CICS JCL:
//HFZHIST DD DISP=SHR,DSN=history-file-dsn
If you use
//HFZHIST DD DISP=SHR,DSN=history-file-dsn
then JCL allocation holds an ENQ on the history file data set name for the full time when CICS is running. However, if you use
DataSets(HFZHIST(history-file-dsn))
then the allocation is dynamically obtained and released when required by Z Abend Investigator. As a result, history file maintenance and renames can be done while a CICS system that has written to it is still running. The
DataSets(HFZHIST(history-file-dsn))
option can even be changed to point to a new history file while CICS is running and takes effect when the next fault entry is created.

The HFZOPTS data set used must be a PDS or PDSE to permit update using ISPF EDIT while CICS is running.