How can I keep my CA Datacom version 14.0 Multi-User Facility (called MUF) from accidentally being started twice?
Article ID: 19086
Updated On:
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Issue/Introduction
Description:
Is there a mechanism within CA Datacom/AD and CA Datacom/DB that will keep me from accidentally starting my Multi-User Facility (called MUF) more than once?
Solution:
There are a number of protection and data integrity features built into version 14.0 of CA Datacom. One of these items involves the use of the SIMPLIFY feature, which provides for a protective enqueue on the CXX, and which means that each CXX and MUF needs to have a unique name. According to the CA Datacom/AD Installation Guide for version 14.0:
A unique CXX name is not only a best practice but a requirement for using the SIMPLIFY feature in CA Datacom/AD Version 14.0. To simplify naming standards, give the CA Datacom/AD MUF name and the CXX name the same value?.CA Datacom forces an enqueue action on the CXX SYSPLEX wide for CA Datacom/AD. A good practice is a unique name for all CXX names for your site. Starting with CA Datacom/AD Version 14.0, the CXX name has no default value, therefore you must determine that unique value yourself.
While the above comments come from the CA Datacom/AD Installation Guide, they apply equally to CA Datacom/DB using Simplify mode.
Once the first MUF is running, if you tried to start another one that was using the same CXX name, the second MUF would abend:
ABEND=S000 U0004 REASON=00000000
and there would be two messages that identify this problem:
DB00242E - REQUIRED ENQ NOT AVAILABLE, MUFNAME=mufname
DB00205E - MULTI-USER ERROR - 0004 MUFNAME=mufname SVC=000
From the CA Datacom/DB Message Reference Guide for Version 14.0:
DB00242E
REQUIRED ENQ NOT AVAILABLE, MUFNAME=mufname
Reason:
This message only occurs in z/OS if the Multi-User Facility (MUF) terminates with a user 4. The message occurs because another job, or another started task, owns the MUF control ENQ that is required.
If this message is followed by a DB00205E - MULTI-USER ERROR - 004 message, this MUF may not enable because the ENQ indicates another MUF is currently executing with the same identity this MUF wants to assume.
Action:
Take action as appropriate in reaction to the message text you received.
DB00205E
MULTI-USER ... ERROR - nnnn .optional-text.
. . .
04
NOT VALID WHEN MUF UP
Reason:
A function was executed that requires the Multi-User Facility to be stopped.
Action:
Before executing the function again, either wait until the Multi-User Facility has been stopped or stop it yourself using the EOJ option of the DBUTLTY COMM function or the related console command: COMM EOJ.
Therefore, if you see the DB00242E error followed by the DB00205E - MULTI-USER ERROR - 0004 error, you will know that the MUF is already running.
For more information about installing CA Datacom/AD in a SYSPLEX environment, please refer to the CA Datacom/AD Installation Guide for Version 14.0 in the section "Starting Your Product > Installation in the SYSPLEX Environment."
For more information about the Simplify feature, please refer to the CA Datacom/DB Database and System Administration Guide for Version 14.0, in the section "Introduction > Simplify Feature."
As always, please contact CA Technologies support for CA Datacom if you have further questions.
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