PH12280: IMPROVE JVMSERVER RECYCLING AFTER TCB FAILURE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When a CICS task has made a call into DB2 (regardless of
  whether it is on a T8 or L8) and then purged, CICS has to abend
  the TCB in order to purge the task since it is currently
  outside of CICS' control.  When the TCB is a T8 that means a
  thread in a JVM is being terminated abnormally.  The JVM is not
  designed to tolerate this scenario and the POSIX standards
  dictate that the process should be terminated.  CICS can't
  guarantee the integrity of the JVM at this point so attempts to
  recycle it.  To recycle the JVM a phaseout is issued by CICS
  against the JVMSERVER so that work can drain gracefully.
  However, it is possible that termination of the TCB by the
  purge prevents phaseout from ever completing.
  
  This APAR will update CICS to escalate through the JVMSERVER
  purge levels to ensure the JVMSERVER is recycled.
  

Local fix

• No Local Fix.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: JVMSERVER hangs at BEING DISABLED       *
  *                      after a DB2 task is purged.             *
  ****************************************************************
  A CICS Java task is forcepurged while control is in Db2 on a T8
  TCB.  This causes the task to abend AD2R and for the T8 TCB to
  be abtermed.  CICS recovery routine gets control and gets a TCB
  failed exception, then CICS issues a phaseout against the
  JVMSERVER to allow work to drain in a graceful manner then
  restart.  However if another thread has also abended CICS will
  wait indefinitely.
  

Problem conclusion

• CICS has been changed to escalate JVMSERVER disable after TCB
  failure to ensure the JVMSERVER is recycled.
  
  The CICS Transaction Server for z/OS V5.3, V5.4 and V5.5
  Knowledge Center has been altered as follows:
  
  In 'Options for JVMs in a CICS environment' in section 'JVM
  server options' in table 1, the following entry is added:
  PURGE_ESCALATION_TIMEOUT|Optional|Optional|Optional|Optional
  
  In 'Descriptions of options' section , the following entry is
  added:
  PURGE_ESCALATION_TIMEOUT={time|15s}
  Controls the time between disable actions when a JVM server
  encounters a TCB failure.  After each timeout CICS escalates to
  the next disable action, for example from phaseout to purge,
  until the JVM server has been recycled. For a Liberty JVM
  server, there is a minimum 60s timeout from phaseout to purge.
  
  In 'DFHSJnnnn messages' in section 'DFHSJ1007 W',
  'System action' is updated:
  
  CICS has detected that an abend has left the JVM in an
  inconsistent state. CICS disables the JVMSERVER resource with
  the PHASEOUT option to allow existing work in the JVM to
  complete where possible and prevent new work from using the JVM.
  If this fails to disable the JVMSERVER within the interval
  specified by the PURGE_ESCALATION_TIMEOUT JVM server option,
  CICS escalates to the next disable action, until the JVMSERVER
  is disabled. After the JVMSERVER is successfully disabled,
  message DFHSJ1008 is issued. CICS attempts to re-enable the
  resource to create a new JVM.
  

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:

  UI66669 UI66670 UI66671 UI66672 UI66673 UI66674 UI66675

Modules/Macros

• DFHAPJVM DFHAPLJP DFHAXIS2 DFHCAL64 DFHCDJNI DFHCDK64 DFHKETIX
  DFHMESJE DFHSJBD  DFHSJDM  DFHSJDS  DFHSJDUF DFHSJIN  DFHSJIS
  DFHSJIX  DFHSJJS  DFHSJL   DFHSJLOG DFHSJNA  DFHSJNDI DFHSJNR
  DFHSJNT  DFHSJPP  DFHSJPTI DFHSJRE  DFHSJRL  DFHSJRM  DFHSJRT
  DFHSJSA  DFHSJSC  DFHSJSM  DFHSJSR  DFHSJST  DFHSJTE  DFHSJTH
  DFHSJTRI DFHSJWL  DFHSJXM  DFJ@H317 DFJ@H356 DFJ@H360 DFJ@H427
  DFJ@H467 DFJ@H468 DFJDTCOE DFJOUTRE DFJWLPBP DFJWLPPL
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI66669

     UP19/11/28 P F911

• R003 PSY UI66671

     UP19/11/30 P F911

• R00D PSY UI66670

     UP19/11/30 P F911

• R100 PSY UI66672

     UP19/11/28 P F911

• R103 PSY UI66674

     UP19/11/30 P F911

• R10D PSY UI66673

     UP19/11/30 P F911

• R200 PSY UI66675

     UP19/11/28 P F911

Fix is available

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