PH17894: CICS JVM SERVER CRASHED DURING START UP

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Migrated to CICS TS 5.5 and JVMs started crashing at start up.
  
  The JVMs failed with a variety of errors;
   - Assertion failures reporting memory corruption
   - 0C4s in core JIT and JVM routines
     > libj9thr29.so at offset x'CDAE' or x'CD7C'
     > libj9vm29.so at offset x'23C2BC'
   - High CPU and looping in JIT routines
  
  In most cases the issues are detected by the JVM and it captures
  diagnostics.  In some cases CICS detects the abend and issues
  message DFHSJ0001 and takes a system dump.
  
  Additional Symptom(s) Search
  Keyword(s): KIXREVxxx
  pool_newElement  omrthread_monitor_destroy
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Various abends or assertion failures    *
  *                      in JVM components when starting up a    *
  *                      JVM server in CICS.                     *
  ****************************************************************
  A JVMSERVER is being ENABLED in CICS.  DFHSJSC processes the JVM
  profile and creates a list of option strings (-Dnnn and -Xnnn)
  that are passed to the JVM when it starts up.  After starting
  the JVM DFHSJSC attempts to free off the storage used for the
  options because it is no longer needed.
  
  A defect existed in DFHSJSC, in the loop that freed the storage,
  which meant that the first storage area was repeatedly freed
  instead of freeing each individual area.
  
  If one of the other JVM threads allocates this storage area
  while the loop is in progress then the storage area could be
  invalidly freed again.  That allows a second part of the JVM to
  allocate the same storage area.
  
  When the storage area ends up being allocated to two separate
  parts of the JVM this can lead to;
   - assertion failures
   - 0C4s in JIT and core JVM routines
   - high CPU usage and a loop in JIT routines
  
  All of these failures cause the JVM server to be unusable.  This
  requires either the JVMSERVER or the CICS region to be recycled.
  

Problem conclusion

• DFHSJSC has been updated to correctly free the storage used for
  option strings that are passed to the JVM during startup of a
  JVM server.
  

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:

  UI66088

Modules/Macros

• DFHSJSC  DFJ@H356 DFJ@H467 DFJ@H468
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R200 PSY UI66088

     UP19/10/30 P F910 ¢

Fix is available

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