Disconnecting multiple CICS regions when recycling a MUF

Products

• Datacom
• Datacom/DB

Issue/Introduction

How do you disconnect multiple CICS regions from a MUF when you need to recycle the MUF and don't want to shut the CICS regions down?

Under normal circumstances, the Datacom MUF should be seen as an operating system task, which is needed for many other kinds of work (CICS regions, Datacom Server connections, batch jobs), and which is started before other work or ended after the other work ends.

For example, the order of starting and stopping might be something like this:

1. Start the Datacom MUF
2. Start the Datacom Server
3. Start the CICS regions
4. ...all the processing takes place here...
5. Shut down the CICS regions
6. Shut down the Datacom Server
7. Shut down the Datacom MUF 

Sometimes, though, it is necessary to recycle the MUF for some change, but you do not want to go through the normal process to shut down and then restart every other connected task. Can this be done?

Environment

z/OS

Datacom/DB Version 15.1 

Resolution

For a singular event like this, you need to disconnect each CICS region from the MUF, and then when these are all done, you can recycle the MUF. Below is a possible method to handle this.

1. 1. For the MUF, issue this console command /F mufJCLname,STATUS
   2. You will get a list of batch jobs and CICS regions using the MUF. I assume you would wait for the batch jobs to finish.
   3. In each region, you would have to issue a transaction to disconnect that region from the MUF. You can either login to each region and enter the transaction, or if your operator consoles are defined in the region, you can issue the command from there. Here is the transaction:
      DBEC PERFORM,DISCONNECT,MUF(??)   or the short version  DBEC P,DISC,MUF(??)
      (Note that the ?? is a wildcard, and should be entered just as it is. You don't need to replace anything there.)
      From the systems console, you might issue /F cicsJCLname,DBEC P,DISC,MUF(??)  and then repeat that for each region.
      As an alternative, you can also issue DBEC PERFORM,SHUTDOWN or DBEC P,SHUT which performs all the same processing for the MUF as when the CICS region is shutting down. Either command will work.
   4. Now recycle your MUF or make whatever changes you need.
   5. When all the work is done and the MUF is running again and ready for use, you will need to connect the regions to the MUF. 
      1. If you used DBEC P,DISC,MUF(??) before, now you use DBEC P,CON,MUF(??)
      2. If you used DBEC P,SHUT before, now you use DBEC PERFORM,STARTUP or DBEC P,START
   6. Finally, issue /F mufJCLname,STATUS again to see that all the CICS regions are connected as they were before.

Additional Information

You can learn more about what you can do with DBEC in the Datacom Tools documentation for DBEC Controlling Local Resources with Enhanced Commands, in the topics Connecting and Disconnecting MUFs and Initiating/Terminating Services.