IT19578: AMQP client not able to retrieve message-id property

APAR status

• Closed as program error.

Error description

• An AMQP application connects to an MQ V8.0.0.5 queue manager
  using an instance of an AMQP channel, and subscribes to a topic
  hosted on that queue manager.
  
  A traditional MQ application publishes messages on the topic.
  The AMQP channel makes a copy of the message, and delivers it to
  the AMQP application. When the AMQP application reads the
  properties of the message it has received, it is unable to find
  the AMQP "message-id" property. As a result, it is unable to use
  the "message-id" as the correlation identifier for a
  request/response flow with a backend system.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of:
  
  - The IBM MQ V8 AMQP channel.
  - The IBM MQ V9 AMQP channel.
  
  who have AMQP clients that connect to a queue manager over an
  instance of the channel, subscribe to a topic hosted on the
  queue manager and receive copies of messages published by MQ
  applications on that topic.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When a message is published on an MQ topic, the AMQP channel
  receives multiple copies of that message - one for each AMQP
  client that has taken out a subscription on that topic. Each
  message is turned into an AMQP message before being sent to the
  relevant client.
  
  The topic:
  
    "Mapping IBM MQ fields onto AMQP fields (outgoing messages)"
  
  in the IBM MQ V8 and V9 sections of IBM Knowledge Center
  contains information about how properties on an MQ message are
  mapped to properties of AMQP messages that are sent to AMQP
  clients. This topic states that:
  
  - The AMQP property "message-id" will be set to a binary
  representation of the MQ message identifier (MQMD.MsgId).
  - The AMQP property "correlation-id" will be set to a binary
  representation of the MQ correlation identifier (MQMD.CorrelId),
  if the MQ message contained a correlation identifier.
  
  The AMQP channel did not implement this functionality. As a
  result, AMQP messages created from MQ messages that were sent to
  AMQP clients:
  
  - Did not have the AMQP "message-id" property set.
  - Did not have the AMQP property "correlation-id" property set,
  if the MQ message contained a correlation identifier.
  

Problem conclusion

• The MQ V8 and V9 AMQP channels have been updated so that when an
  AMQP message is created from an MQ message:
  
  - A binary representation of the MQ message identifier
  (MQMD.MsgId) is copied into the AMQP property "message-id".
  - A binary representation of the MQ correlation identifier
  (MQMD.CorrelId) is copied into the AMQP property
  "correlation-id", if the MQ message had a correlation
  identifier.
  
  This ensures that the AMQP properties "message-id" and
  "correlation-id" (if appropriate) are set on the AMQP messages
  sent to AMQP clients.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.8
  v9.0 CD    9.0.4
  v9.0 LTS   9.0.0.3
  
  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 BASE MULTIP

• Fixed component ID

  5724H7251

Applicable component levels

• R800 PSY

     UP