IV83785: JMS classes may send data to the queue manager which is not 4-BYTE aligned

APAR status

• Closed as program error.

Error description

• An application running within the WebSphere Application Server
  8.5.5.1 environment is communicating with a queue manager
  running on the Solaris operating system.
  
  Occasionally the TCP connection between the application server
  and the queue manager is disconnected, with the following
  exception is reported in the application server SystemOut.log
  file:
  
  CWSJY0003W: JMSCC3036: An exception has been delivered to the
  connection's exception listener: '
  Message : com.ibm.msg.client.jms.DetailedJMSException:
  JMSWMQ1107: A problem with this connection has occurred.
  An error has occurred with the WebSphere MQ JMS connection.
  Use the linked exception to determine the cause of this error.
  ... ... ...
  com.ibm.mq.MQException: JMSCMQ0001: WebSphere MQ call failed
  with compcode '2' ('MQCC_FAILED') reason '2009'
  ('MQRC_CONNECTION_BROKEN').
  com.ibm.msg.client.wmq.common.internal.Reason.createException
  com.ibm.msg.client.wmq.internal.WMQConnection.consumer
  com.ibm.mq.jmqi.remote.api.RemoteHconn.callEventHandler
  com.ibm.mq.jmqi.remote.api.RemoteHconn.driveEventsEH
  com.ibm.mq.jmqi.remote.impl.RemoteDispatchThread.processHconn
  com.ibm.mq.jmqi.remote.impl.RemoteDispatchThread.run
  com.ibm.msg.client.commonservices.workqueue.WorkQueueItem.runTas
  k
  com.ibm.msg.client.commonservices.workqueue.SimpleWorkQueueItem.
  runItem
  com.ibm.msg.client.commonservices.workqueue.WorkQueueItem.run
  com.ibm.ws.wmqcsi.workqueue.WorkQueueManagerImpl$WorkQueueRunnab
  le.run
  java.lang.Thread.run
  
  followed by messages of the form:
  
  J2CA0056I: The Connection Manager received a fatal connection
  error from the Resource Adapter for resource
  JMS$MY_MQ_CF$JMSManagedConnection@7. The exception is:
  com.ibm.msg.client.jms.DetailedJMSException: JMSWMQ2007: Failed
  to send a message to destination 'MY.QUEUE'.
  JMS attempted to perform an MQPUT or MQPUT1; however WebSphere
  MQ reported an error.
  
  
  
  Simultaneously, an error is put into the queue manager error
  logs (AMQERR01.LOG) which reads:
  
  ----- amqxfdcx.c : 888
  --------------------------------------------------------
  04/13/16 13:39:48 - Process(13190.222171) User(mqm)
  Program(amqrmppa)
                      Host(myHost) Installation(Installation1)
                      VRMF(8.0.0.3)
  AMQ9504: A protocol error was detected for channel 'MY.CHANNEL'.
  
  EXPLANATION:
  During communications with the remote queue manager, the channel
  program
  detected a protocol error. The failure type was 32758 with
  associated data of
  2.
  ACTION:
  Contact the systems administrator who should examine the error
  logs to
  determine the cause of the failure.
  

Local fix

• Limit the size of the messages being sent to the queue manager
  to be less than 32KB
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of the WebSphere MQ classes for JMS, which includes the
  WebSphere MQ Resource Adapter.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The Solaris operating system has a requirement such that all
  data sent to the queue manager over TCP must be byte-aligned at
  a 4-byte boundary, for example a TCP data packet of 400 bytes is
  permitted, a 402 byte packet would be rejected.
  
  The WebSphere MQ classes for JMS attempts to ensure that this
  byte-alignment is used.  However under a specific set of
  circumstances when sending a maximum size MQ data packet
  (approximately 32KB), the data packet size sent may be 32,758
  bytes, which is not 4-byte aligned.
  
  When this occurs, the queue manager detects the anomaly and
  closes the TCP socket, reporting the error in the queue manager
  error logs.  On the application side, the WebSphere MQ classes
  for JMS then report a MQRC 2009 exception to indicate that the
  TCP socket is no longer connected to the queue manager, and the
  message sending operation fails.
  
  
  The specific condition upon which this happens is as follows:
  
  (1) A maximum number of 'hconn' objects have been established
  over a TCP socket.  This maximum value is determined by the
  channel attribute SHARECNV.  For the JMS API, this corresponds
  to the number of JMS Connections and Sessions which have been
  created.
  
  (2) An additional 'hconn' is created, which causes a new TCP
  socket to be created.  This must be for a new JMS Session, as
  opposed to a JMS Connection.
  
  (3) The 'hconn' is closed, resulting in the TCP socket being
  closed.
  
  (4) A new 'hconn' is requested.
  
  (5) A application attempts to send a message to the queue
  manager which is as big as or greater than the size of 32,757
  bytes.
  
  
  It should be noted that APAR IC98323 (introduced in fix packs
  7.1.0.5, 7.5.0.4) changes the behaviour of conditions upon which
  the problem is encountered.  With the code change associated
  with APAR IC98323, there are no known conditions where this
  byte-alignment problem would be encountered.  However this APAR
  IV83785 is still valid in making the byte alignment mechanism
  more robust to future changes.
  

Problem conclusion

• The code has been updated to ensure that a maximum TCP data
  packet size of 32,756 bytes is used instead of the previous
  value of 32,758 bytes, which was not 4-byte aligned.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.1       7.1.0.8
  v7.5       7.5.0.8
  v8.0       8.0.0.6
  v9.0 CD    9.0.1
  v9.0 LTS   9.0.0.1
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

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

  WMQ SOL SPARC

• Fixed component ID

  5724H7223

Applicable component levels