IZ94267: The endmqm command does not end the queue manager and no agent processes are seen running for this queue manager.

WebSphere MQ V6.0 Fix Pack 6.0.2.11
WebSphere MQ V6.0 for iSeries Fix Pack 6.0.2.11
WebSphere MQ V7.0 Fix Pack 7.0.1.6
WebSphere MQ V7.0.1 for i5/OS Fix Pack 7.0.1.6
WebSphere MQ 6.0 for HP OpenVMS Alpha and Itanium - Fix Pack 6.0.2.11 (FP 04)

APAR status

• Closed as program error.

Error description

• When endmqm -i <Qmgrname> is executed, the queue manager does
  not end and it hangs. Some of the queue manager processes are
  found to be still running. After killing the processes, the
  queue manager can be started and stopped successfully without
  any errors.
  
  A process listing is likely to show that no agent processes are
  running. An MQ trace can be taken and the trace for amqzxma0
  may show calls to MQ function "xcsCheckProcess" where one of
  the calls is checking for an unexpected pid, i.e. a pid of a
  process not related to this queue manager.
  
  Example of MQ trace showing a call to xcsCheckProcess checking
  whether pid 18821 is alive.
  
  17:05:14.998221    18813.1           :      --{
  xcsCheckProcess
  17:05:14.998232    18813.1           :           pid(18821)
  17:05:14.998243    18813.1           :           Data:
  0x00004985
  17:05:14.998257    18813.1           :      --}
  xcsCheckProcess rc=OK
  
  Example of a process listing showing that pid 18821 is for a
  running process that we would not expect the queue manager to
  be checking:
  
  userx   18821 18819   0   Feb 08 pts/5       0:00 -ksh
  
  This example would indicate that the endmqm is hanging due to
  the problem documented in this APAR.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users who issue endmqm may rarely encounter this problem.
  
  Platforms affected:
  All Distributed (iSeries, all Unix and Windows)
  ****************************************************************
  PROBLEM SUMMARY:
  There is a window of opportunity when an agent ends, for a
  completely separate process to start running, before the queue
  manager checks the liveness of the agent pid. In that
  situation, the queue manager knows that the agent is ending,
  but believes it has yet to exit. If an endmqm (with or without
  the -i option) is issued, it will wait (hang) indefinitely
  until periodic checks on the agent pid show that pid to be for
  a non-existent process. If the "completely separate process"
  that started running continues to run, the endmqm will never
  end.
  

Problem conclusion

• The mechanism for checking the death of an agent process has
  been revised to avoid the possibility of a hang in the case
  that an agent's pid has been reused by some other process.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v6.0
  Platform           Fix Pack 6.0.2.11
  --------           --------------------
  Windows            U200326
  AIX                U839822
  HP-UX (PA-RISC)    U840685
  HP-UX (Itanium)    U840690
  Solaris (SPARC)    U840686
  Solaris (x86-64)   U840693
  iSeries            tbc_p600_0_2_11
  Linux (x86)        U840687
  Linux (x86-64)     U840692
  Linux (zSeries)    U840688
  Linux (Power)      U840689
  Linux (s390x)      U840691
  
                     v7.0
  Platform           Fix Pack 7.0.1.6
  --------           --------------------
  Windows            U200328
  AIX                U840698
  HP-UX (PA-RISC)    U841555
  HP-UX (Itanium)    U841560
  Solaris (SPARC)    U841556
  Solaris (x86-64)   U841562
  iSeries            tbc_p700_0_1_6
  Linux (x86)        U841557
  Linux (x86-64)     U841561
  Linux (zSeries)    U841558
  Linux (Power)      U841559
  
  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 LIN X86 V6

• Fixed component ID

  5724H7204

Applicable component levels

• R602 PSY

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