PM01840: JAVA SOCKET CODE MAKES BAD CALL TO SETSOCKOPT FOR EVERY BIND OPERATION.

APAR status

• Closed as program error.

Error description

• In certain situations on z/OS, when IPv6 is enabled, socket
  operations in Java will issue extraneous and invalid calls to
  the getsockopt and setsockopt system services.
  
  These calls will fail, but will not cause any problems with
  sockets or data communication.
  
  A trace of USS calls (either via CTRACE or GTF trace with SLIPs)
  may show these repeated failures under the covers.
  

Local fix

• To eliminate the calls to get/setsockopt, you will need to
  deactivate IPv6 support in the Java Virtual Machine.
  
  This can be accomplished with the Java System Property:
  java.net.preferIPv4Stack = true
  
  At the commandline this can be set with a -D commandline option.
  Alternately the IBM_JAVA_OPTIONS environment variable can be
  used to set this at a higher scope for all running JVM processes
  with access to the variable.
  
  IBM_JAVA_OPTIONS = -Djava.net.preferIPv4Stack=true
  
  
  NOTE:
  The extraneous and erroneous system calls do not cause any
  failures of application or JVM functionality. The only
  potentially visible symptom is a performance impact while
  performing socket operations.
  The Local Fix / Circumvention above should be used only in cases
  where the syscall error performance issue is causing an impact
  on the system. And only when IPv6 communication is not required.
  

Problem summary

• Java socket code is making extra calls to setsockopt and
  getsockopt for every bind operation resulting in failures
  

Problem conclusion

• This defect will be fixed in:
  5.0.0 SR11 FP2
  .
  Invalid calls are removed from NET_Bind function.
  

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:

  PM13601

Fix information

• Fixed component name

  JAVA 5 Z/OS 31

• Fixed component ID

  620500105

Applicable component levels

• R500 PSY

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