IX90156: OUTOFMEMORYERROR THROWN FROM CDRREADER.READBYTESFORSTRING

APAR status

• Closed as program error.

Error description

• Error Message: "java/lang/OutOfMemoryError" - "Java heap space"
  received
  .
  Stack Trace: 3XMTHREADINFO      "WebContainer : 25"
  J9VMThread:0x0000000083D81200, j9thread_t:0x00007F947293DAB0,
  java/lang/Thread:0x0000000010731838, state:R,
  prio=53XMJAVALTHREAD            (java/lang/Thread getId:0xD50,
  isDaemon:true)3XMTHREADINFO1            (native thread
  ID:0x7589, native priority:0x5, native
  policy:UNKNOWN)3XMTHREADINFO2            (native stack address
  range from:0x00007F9489C39000, to:0x00007F9489C7A000,
  size:0x41000)3XMTHREADINFO3           Java
  callstack:4XESTACKTRACE                at
  com/ibm/rmi/iiop/CDRReader.readBytesForString(CDRReader.java:239
  4(Compiled Code))4XESTACKTRACE                at
  com/ibm/rmi/iiop/CDRReader.readStringOrIndirection(CDRReader.jav
  a:496(Compiled Code))4XESTACKTRACE                at
  com/ibm/rmi/iiop/CDRReader.read_string(CDRReader.java:489(Compil
  ed Code))4XESTACKTRACE                at
  com/ibm/rmi/IOR.read(IOR.java:350(Compiled Code))4XESTACKTRACE
               at
  com/ibm/rmi/iiop/CDRReader.read_Object(CDRReader.java:1129(Compi
  led Code))4XESTACKTRACE                at
  com/ibm/rmi/iiop/CDRReader.fast_read_abstract_interface(CDRReade
  r.java:1930(Compiled Code))4XESTACKTRACE                at
  com/ibm/rmi/iiop/CDRReader.fast_read_abstract_interface(CDRReade
  r.java:1918(Compiled Code))4XESTACKTRACE                at
  com/ibm/rmi/io/IIOPInputStream.readObjectDelegate(IIOPInputStrea
  m.java:392(Compiled Code))4XESTACKTRACE                at
  com/ibm/rmi/io/IIOPInputStream.readObjectOverride(IIOPInputStrea
  m.java:663(Compiled Code))4XESTACKTRACE                at
  java/io/ObjectInputStream.readObject(ObjectInputStream.java:347(
  Compiled Code))4XESTACKTRACE                at
  java/util/HashMap.readObject(HashMap.java:953(Compiled
  Code))4XESTACKTRACE                at
  sun/reflect/GeneratedMethodAccessor114.invoke(Bytecode
  PC:40(Compiled Code))4XESTACKTRACE                at
  sun/reflect/DelegatingMethodAccessorImpl.invoke(DelegatingMethod
  AccessorImpl.java:25(Compiled Code))4XESTACKTRACE
  at java/lang/reflect/Method.invoke(Method.java:600(Compiled
  Code))4XESTACKTRACE                at
  com/ibm/rmi/io/IIOPInputStream.invokeObjectReader(IIOPInputStrea
  m.java:1775(Compiled Code))
  .
  Under rare circumstance the same issue can formulate itself as a
  CORBA MARSHAL exception rather than OutOfMemoryError.
  

Local fix

• From the stack trace, we can see that ORB tried to allocate a
  large string while trying to read a Hashmap
  -java/util/HashMap.readObject. Application code needs to be
  modified to ensure that they are thread-safe for
  serialization. Note that, similar errors can also be seen for
  other non thread-safe collections.
  

Problem summary

• This problem is caused when an HashMap is modified (Values added
  or removed) while it is being marshalled. While marshalling ORB
  first writes the size of the HashMap to the stream and then the
  key-value pairs. When an hashmap is modified while it is being
  serialized the data written is inconsistent and ORB trips while
  trying to read the additional or missing key-value pair.This
  issue is also applicable to other collection objects which are
  not thread safe.
  

Problem conclusion

• ORB cannot determine whether a collection object was modified
  while being marshalled, however we have added better error
  handling, Rather than trying to allocate huge strings which lead
  to OOM, ORB will discard such requests and log ffdc
  appropriately.This fix will only ensure that application doesnt
  terminates abruptly with OOM. Application code still needs to be
  changed to address the thread safety issue.
  .
  This APAR will be fixed in the following Java Releases:
     6 R1 SR8 FP3   (6.1.8.3)
     7    SR8 FP10  (7.0.8.10)
     7 R1 SR2 FP10  (7.1.2.10)
     6    SR16 FP3  (6.0.16.3)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the Service
  Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

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:

Fix information

• Fixed component name

  ORB

• Fixed component ID

  620700123

Applicable component levels

• R260 PSY

     UP

• R600 PSY

     UP