IT17550: MFT agent ABENDs when starting with BFGSS0034E message after migration from V7.5 to V8

APAR status

• Closed as program error.

Error description

• After upgrading to WebSphere MQ Managed File Transfer V7.5.0.6,
  agents that were processing transfers that did not complete
  before being upgraded do not start after the maintenance is
  applied.  The agent ABENDs with the following ABEND log file
  written:
  
  Level:      f750-FP-006-20160219-0939
  Time:       25/10/2016 12:15:21:543 BST
  Thread:     20 (RecoveryThread)
  Class:      com.ibm.wmqfte.statestore.impl.FTEStateUtils
  Method:     getStateFromBuffer
  Probe:      ABEND_002
  Cause:      com.ibm.wmqfte.statestore.FTEStateStoreException:
  BFGSS0034E: An internal error has occurred relating to a message
  on the STATE Queue. Transfer ID null.
  
  com.ibm.wmqfte.statestore.FTEStateStoreException:
  BFGSS0034E: An internal error has occurred relating to a message
  on the STATE Queue. Transfer ID null.
    at com.ibm.wmqfte.statestore.impl.FTEMutableCommonState.<init>
      (FTEMutableCommonState.java:349)
    at com.ibm.wmqfte.statestore.impl.FTEMutableSenderState.<init>
      (FTEMutableSenderState.java:179)
    at
  com.ibm.wmqfte.statestore.impl.FTEStateUtils.getStateFromBuffer
      (FTEStateUtils.java:246)
    at
  com.ibm.wmqfte.statestore.impl.FTEStateUtils.getStateFromMessage
      (FTEStateUtils.java:282)
    at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence.recover
      (FTEStateStorePersistence.java:1409)
    at com.ibm.wmqfte.statestore.impl.FTEStateStoreImpl.recover
      (FTEStateStoreImpl.java:1777)
    at
  com.ibm.wmqfte.agent.AgentRecoveryRunnable.recoverStateStore
      (AgentRecoveryRunnable.java:785)
    at com.ibm.wmqfte.agent.AgentRecoveryRunnable.run
      (AgentRecoveryRunnable.java:204)
    at java.lang.Thread.run(Thread.java:767)
    at com.ibm.wmqfte.thread.FTEThread.run(FTEThread.java:70)
  

Local fix

• Clean the agent of outstanding transfers using the fteCleanAgent
  command with the "-trs" option.  This will remove outstanding
  transfer messages from the agent's STATE and COMMAND queues.
  Transfers cleaned will need to be requested again once the agent
  is restarted.
  
  Please note, because agents (typically) work in pairs for file
  transfer, when one agent is cleaned so must any other partner
  agents that it is receiving file transfers from or sending files
  to.  This is to ensure state between the agent pairs does not
  become out of sync.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects all users of:
  
    - WebSphere MQ V7.5.0.6 and V7.5.0.7 Managed File Transfer
    - IBM MQ V8.0.0.4 and V8.0.0.5 Managed File Transfer
    - IBM MQ V9.0.0.0 Managed File Transfer
  
  who have upgraded from an earlier MFT version and have an agent
  that has not completed all of its file transfer processing
  (i.e., the agent's SYSTEM.FTE.STATE queue is not empty).
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  In MQ Managed File Transfer, an agent will write a state message
  to its SYSTEM.FTE.STATE queue to persist the definition and
  progress of an active file transfer.  The format and data within
  a transfer state message can change between versions to record
  new information.  For example, APAR IT03450 added additional
  information to an agent's state message to support the new
  function introduced in that APAR.
  
  If an older version agent was processing one or more file
  transfers that did not complete, but had checkpointed at least
  once, before it was stopped and upgraded, then the agent post
  upgrade would ABEND on startup.  This was because the upgraded
  agent expected additional information in the transfer state
  message, regarding the new function added in APAR IT03450, that
  was not present.  The agent therefore misinterpreted the bytes
  of the state message which can lead to ABENDs.
  

Problem conclusion

• The MQ Managed File Transfer agent code has been updated to
  ensure that agents determine the version of the agent that
  created the transfer state message before attempting to read
  bytes corresponding the new function added by APAR IT03450.  As
  a result, if a transfer state message was created by an agent
  that does not have the function new added by APAR IT03450 then,
  after this APAR, the agent will not attempt to read the
  additional information from the state message for this new
  function.
  
  Note that if an interim fix for APAR IT03450 had been applied to
  an MQ MFT V7.5.0.5, V8.0.0.3 or earlier installation, then all
  transfers must be complete before the agent is upgraded or
  maintenance is applied, even if the version that the agent is
  being upgraded to includes this APAR.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  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 MQ 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 MFT

• Fixed component ID

  5724H7242

Applicable component levels

• R750 PSY

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