PH65974: NEVER-ENDING LOOP OF CQRY TRANSACTIONS IS POSSIBLE WHEN SHARING A CSD THAT IS AT THE CICS/TS 6.1 LEVEL (OR ABOVE).

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CICS/TS 5.5 and CICS/TS 5.6 supply a definition for transaction
  CQRY in CSD group DFHSTAND.
  
  Starting at CICS/TS 6.1, there is no longer a CSD definition in
  group DFHSTAND for CQRY as the definition is built internally.
  But also starting at CICS/TS 6.1 there is a CSD definition for
  CQRY in compatibility group DFHCOMPJ for use by CICS/TS 5.5 and
  CICS/TS 5.6 regions that are sharing a CSD initialized at or
  upgraded to the CICS/TS 6.1 (or above) level.
  
  If a CICS/TS 5.5 or 5.6 region is sharing a CICS/TS 6.1 (or
  above) CSD and the CQRY transaction definition is not
  successfully installed, there will be a loop of CQRY
  transactions when terminals that require a Query log on to CICS.
    CICS will attempt to initiate CQRY on the terminal.   Since
  there is no installed CQRY definition, the DFHACP program is
  invoked to send a DFHAC2001 "Transaction 'CQRY' is not
  recognized." message to the terminal.  As soon as that is done,
  a new CQRY transaction is attached to do the same thing.  This
  continues in a never-ending loop as long as the terminal stays
  logged on to CICS.
  
  In some cases where there is no session level pacing on the
  terminal (such as for a local non-sna terminal), there is no
  restraint on the sending of the DFHAC2001 message to the
  terminal and it can lead to ECSA buffer shortages for VTAM.
  
  The following z/OS Communication Server message can be seen
  indicating a buffer pool shortage:
  
  IST154I EXPANSION FAILED FOR bp BUFFER POOL - CODE x,
  IST561I STORAGE UNAVAILABLE: bp BUFFER POOL
  
  These may be followed by further messages identifying the LU
  using a large portion of the buffer and reporting that VTAM has
  terminated the LU-LU session because the session is
  depleting the bp buffer pool:
  
  IST930I nodename1 nodename2 SESSION USING percentage OF bpBUF
  IST1099I SESSION TERMINATED, DEPLETING bp BUFFER POOL
  

Local fix

• To avoid this problem,  when sharing a CICS/TS 6.x CSD, make
  sure DFHCOMPJ (and all other compatibility groups necessary for
  your release) are in a CSD list that is installed as part of the
  GRPLIST SIT parameter.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: A loop of DFHAC2001 messages reporting  *
  *                      that the CQRY transaction can not be    *
  *                      found can be seen on a 3270 terminal    *
  *                      when sharing a CICS V6.x CSD with a     *
  *                      CICS V5.x region.                       *
  ****************************************************************
  When sharing a CICS TS V6.x CSD with a CICS TS V5.x region, it
  is possible that the CQRY transaction could fail to install if
  the required method of sharing CSDs is not followed.
  As a result of the CQRY transaction not being installed in the
  CICS region, attempts to log on to queryable terminals result in
  a loop of attach attempts for CQRY. Each of these attempts
  results in a CSAC transaction being attached to handle the
  failure, and a DFHAC2001 message to be sent to the terminal.
  
  This loop of DFHAC2001 messages being sent to the terminal can
  result in issues in VTAM.
  
  In some cases this can lead to ECSA buffer shortages for VTAM.
  
  The following z/OS Communication Server message can be seen
  indicating a buffer pool shortage:
  
  IST154I EXPANSION FAILED FOR bp BUFFER POOL - CODE x,
  IST561I STORAGE UNAVAILABLE: bp BUFFER POOL
  
  These may be followed by further messages identifying the LU
  using a large portion of the buffer and reporting that VTAM has
  terminated the LU-LU session because the session is
  depleting the bp buffer pool:
  
  IST930I nodename1 nodename2 SESSION USING percentage OF bpBUF
  IST1099I SESSION TERMINATED, DEPLETING bp BUFFER POOL
  

Problem conclusion

• CICS will ensure there is a transaction definition installed for
  the CQRY transaction at start up.
  

Temporary fix

Comments

APAR Information

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

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

  UO03938 UO03943

Modules/Macros

• DFHXMDM
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R200 PSY UO03938

     UP25/07/09 P F507 ¢

• R300 PSY UO03943

     UP25/07/05 P F507 ¢

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.