IT44108: IBM MQ MFT agent ends unexpectedly with a NullPointerException

APAR status

• Closed as program error.

Error description

• The IBM MQ MFT agent process ends unexpectedly, generating an
  ABEND FDC with exception and stack like:
  
  Method:     uncaughtException
  Probe:      ABEND_001
  Cause:      java.lang.NullPointerException
  java.lang.NullPointerException
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$FTEMutab
  leSenderStateRef.getStateFromPersistentStore(FTEStateStorePersis
  tence.java:365)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$FTEMutab
  leSenderStateRef.getFTEMutableSenderState(FTEStateStorePersisten
  ce.java:319)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$Transfer
  RequestQueue.get(FTEStateStorePersistence.java:662)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$SenderTr
  ansferRequestMap.get(FTEStateStorePersistence.java:884)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence.getSende
  rState(FTEStateStorePersistence.java:2178)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence.getImmut
  ableSenderState(FTEStateStorePersistence.java:2048)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStoreImpl.getTransferStat
  e(FTEStateStoreImpl.java:4533)
          at
  com.ibm.wmqfte.scheduler.FTEScheduler.sendFTR(FTEScheduler.java:
  676)
          at
  com.ibm.wmqfte.scheduler.FTEScheduler.serviceSchedulerQueue(FTES
  cheduler.java:629)
          at
  com.ibm.wmqfte.cmdhandler.impl.FTECommandThread.pollScheduler(FT
  ECommandThread.java:568)
          at
  com.ibm.wmqfte.cmdhandler.impl.FTECommandThread.run(FTECommandTh
  read.java:344)
          at java.lang.Thread.run(Thread.java:825)
          at
  com.ibm.wmqfte.thread.FTEThread.run(FTEThread.java:70)
  
  A message will also be logged in the agent.log file indicating
  that the agent has ended and an FDC generated.
  

Local fix

• Once the agent is restarted (if needed use kill -9) the
  transfers all seem to resume and complete.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of IBM MQ Managed File Transfer agents
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  While attempting to start a scheduled transfer, the IBM MQ MFT
  agent retrieved a state message for a previously scheduled
  transfer to check on its state before starting the new transfer
  - however there was a problem with the content of the message
  that meant it could not be parsed for the expected contents -
  this resulted in a NullPointerException, which was not handled
  correctly while parsing the message, and so this propagated up
  the stack and led to the agent ending expectedly, with the ABEND
  FDC showing the NullPointerException and stack:
  
  java.lang.NullPointerException
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$FTEMutab
  leSenderStateRef.getStateFromPersistentStore(FTEStateStorePersis
  tence.java:365)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$FTEMutab
  leSenderStateRef.getFTEMutableSenderState(FTEStateStorePersisten
  ce.java:319)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$Transfer
  RequestQueue.get(FTEStateStorePersistence.java:662)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence$SenderTr
  ansferRequestMap.get(FTEStateStorePersistence.java:884)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence.getSende
  rState(FTEStateStorePersistence.java:2178)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStorePersistence.getImmut
  ableSenderState(FTEStateStorePersistence.java:2048)
          at
  com.ibm.wmqfte.statestore.impl.FTEStateStoreImpl.getTransferStat
  e(FTEStateStoreImpl.java:4533)
          at
  com.ibm.wmqfte.scheduler.FTEScheduler.sendFTR(FTEScheduler.java:
  676)
          at
  com.ibm.wmqfte.scheduler.FTEScheduler.serviceSchedulerQueue(FTES
  cheduler.java:629)
          at
  com.ibm.wmqfte.cmdhandler.impl.FTECommandThread.pollScheduler(FT
  ECommandThread.java:568)
          at
  com.ibm.wmqfte.cmdhandler.impl.FTECommandThread.run(FTECommandTh
  read.java:344)
          at java.lang.Thread.run(Thread.java:825)
          at
  com.ibm.wmqfte.thread.FTEThread.run(FTEThread.java:70)
  

Problem conclusion

• Any problems in parsing transfer state messages are now handled
  and the agent is ended in a managed way instead of abending. The
  content of the message that could not be parsed is written to an
  FDC that will be generated before the agent ends to aid in
  diagnosis of the underlying message corruption issue.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.3 LTS   9.3.0.20
  v9.4 LTS   9.4.0.0
  
  The latest available maintenance can be obtained from
  'IBM MQ Recommended Fixes'
  https://www.ibm.com/support/pages/recommended-fixes-ibm-mq
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'IBM MQ
  Planned Maintenance Release Dates'
  https://ibm.biz/mqplannedmaintenance
  
  ---------------------------------------------------------------
  

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

  MQ BASE V9.3

• Fixed component ID

  5724H7291

Applicable component levels