PH67117: HIGH NUMBER OF CSQSNAP AND SVC DUMPS SINCE UPGRADING TO MQ V9.4 LTS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The FFST is occurring when trying to wait for the
  SSLResetAcknowledged thread event. This event is waited on when
  a client proposes an SSL key reset by sending a
  rfpSAT_PAUSE_DATA_SENDS socket action TSH. The problem is that
  the thread event is not re-initialised between waits. This
  results in the MQXWD.Reserved2 field being left set from the
  post of the thread event. A poster sets this field to the DPRO
  address via field DREQPROC which is overlaid over the MQXWD.
  Previously this was fine because CSQXADPM used to clear
  MQXWD.Reserved2 at the end of the MQXWAIT. However, this no
  longer happens at V940.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 4 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Message CSQX053E is issued from         *
  *                      CSQXFFST reporting error information in *
  *                      the CSQSNAP data set when clients       *
  *                      connecting using SSL/TLS channels       *
  *                      initiate Secret Key Reset. The contents *
  *                      of CSQSNAP show the FFST was issued by  *
  *                      xcsWaitThreadEvent with additional      *
  *                      information "MQXWAIT failed".           *
  ****************************************************************
  When a client application connected using SSL/TLS initiates a
  Secret Key Reset, the channel's receive thread issues
  xcsWaitThreadEvent to wait for an acknowledgment. During this
  wait, the XWD used for an internal MQXWAIT call can contain
  values in reserved fields that were unexpectedly returned on
  earlier MQWAIT calls, causing the MQXWAIT to fail with
  MQRC_XWAIT_ERROR (2108 0x083C), resulting in the FFST being
  captured.
  

Problem conclusion

• The unexpected values are no longer returned in the input MQXWD
  fields.
  

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:

  UO04375

Modules/Macros

• CSQXADPM
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R400 PSY UO04375

     UP25/09/13 P F509

Fix is available

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