IT24124: FOR MQ FOR NONSTOP ON ITANIUM 5.3.1, EC REPEATEDLY RESTARTS CERTAIN CHILD PROCESS (LQMA).

APAR status

• Closed as program error.

Error description

• EC repeatedly restarts certain child process (LQMA) which lead
  to high CPU usage. The EC gets into a loop and spawns new LQMAs
  trying a process name that is already in use. This is a
  situation the EC is not prepared to handle as keeping a list of
  free numbers and this number is part of the free list. EC is
  unable to find a way out of this loop as long as the process
  name stays is in use. This process spawn loop produces a lot of
  load on the system.
  This APAR is working on an EC enhancement to bypass a process
  name if a process start fails because of a name conflict.
  

Local fix

• The customer should make sure there are no processes matching
  the agent process name rule. If it happens, the customer could
  check if the process using the conflicting process name can be
  stopped and restarted with a different process name. However,
  stopping the process does not always resolve the problem.
  If the execution controller continues to create processes,
  the CPU usage will remain high. If that happens,
  the customer needs to restart the Queuemanager.
  

Problem summary

•  Root cause is a wrong error handling inside the
  EC in the case of a failed process start. The EC receives EAGAIN
  and _TPC_BADNAME_FERROR on process completion and tries the same
  name again.
  

Problem conclusion

•  The error handling in the case of an agent
  process creation failure has been modified. A process name that
  just caused a bad name error will not be used on the next
  attempt.
  

Temporary fix

•  Don't use process names for non-MQ processes that
  matches the naming rule defined by the user in qmproc.ini.
  

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

  WEBS MQ NSS ITA

• Fixed component ID

  5724A3902

Applicable component levels