PH44114: IBM HTTP SERVER ON WINDOWS MAY HANG DURING SHUTDOWN OR RESTART

APAR status

• Closed as program error.

Error description

• The reinitialization of the parent process may hang on Windows,
  which is triggered by MaxRequestsPerChild and graceful restarts.
  
  This prevents a new child process from being started, so new
  connections cannot be accepted.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM HTTP Server on Windows     *
  *                  with                                        *
  *                  mod_mpmstats loaded                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: IHS may appear to hang if               *
  *                      MaxRequestsPerChild is non-zero,        *
  *                      because a                               *
  *                      replacement process will not be         *
  *                      launched.                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  On Windows, mod_mpmstats runs in the IHS parent process and
  MaxRquestsPerChild causes the parent to gracefully reload.
  An unknown problem may block the delivery of the restart signal
  to the mod_mpmstats thread, which will cause the
  reinitialization of the parent process to hang indefinitely.
  If the parent process cannot reinitialize, it cannot spawn a
  replacement connection-handling child process.
  

Problem conclusion

• mod_mpmstats was updated to use a fallback mechanism to get
  notified of restarts. This backup mechanism is enabled by defaul
  
  The fix for this APAR is targeted for inclusion in IBM HTTP
  Server fix packs 8.5.5.22 and 9.0.5.12. For more information, se
  'Recommended Updates for WebSphere Application Server':
  https://www.ibm.com/support/pages/node/715553
  

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

  IBM HTTP SERVER

• Fixed component ID

  5724J0801

Applicable component levels