PH54431: DFHMQ0370 AND DFHMQ0371 MESSAGES ISSUED IN CICS REGION WITHOUT A STARTED MQMONITOR

APAR status

• Closed as program error.

Error description

• You have a CICS region that has gone MAXTASK. During the period
  that the region is at MXT you see many DFHMQ0370 and DFHMQ0371
  messages issued like the following:
  
  DFHMQ0370 I 04/18/2023 03:44:15 MQMONITORs are
  currently restricted to 104 MQGETs per second.
  DFHMQ0371 I 04/18/2023 03:44:15 MQMONITORs do not have
  a restriction on the number of MQGETs that can be issued per
  second.
  
  Code added at CICS TS 5.5 will post the CKAM transaction when
  MXT is hit, which drives code in DFHMQMON to work out the number
  of MQGETs an MQMONITOR can issue per second and issue the
  DFHMQ0370 message. Trace on the problem shows that DFHMQMON is
  getting posted out of its wait everytime it goes in and out of
  MXT and issues the DFHMQ0370 and DFHMQ0371 messages.
  
  However, your CICS region does not have an MQMONITOR defined,
  started or in use therefore these messages should not be driven.
  
  Additional Symptom(s) Search Keyword(s): KIXREVQWD
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Large number of DFHMQ0370 and DFHMQ0371 *
  *                      messages being issued.                  *
  ****************************************************************
  It is possible to see a large number of DFHMQ0370 and DFHMQ0371
  messages being issued, even when the CICS region is running
  without any MQMonitors defined.
  This will be seen should the CICS region be hitting MXT a lot.
  The DFHMQ0370 and DFHMQ0371 messages are used to inform uses of
  the rate MQ GET request can be processed by the MQMonitors when
  the CICS region is at MXT. However, these messages are still
  being issued even when no MQMonitor is defined to the CICS
  region.
  

Problem conclusion

• DFHMQMON has been changed to only issue the DFHMQ0370 and
  DFHMQ0371 messages only every 15 seconds if an MQMonitor is
  defined, and not at all if no MQMonitor is defined.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  PH53978

• APAR is sysrouted TO one or more of the following:

  UI91975

Modules/Macros

• DFHMQMON
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI91975

     UP23/05/26 P F305