PK75900: CHANGES MADE TO A WMQ INSTALLATION WHILE AN APPLICATION SERVER IS STOPPED CAN PREVENT APPS FROM USING MESSAGING AFTER STARTUP

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• If an external WebSphere MQ installation pointed to by
  MQ_INSTALL_ROOT is updated while application servers are
  stopped, and that update contains a change to the number of
  Java or native libraries included in the WebSphere MQ JMS
  client (or the MQ_INSTALL_ROOT itself is changed), application
  servers may log WMSG1612E or WMSG1614E messages during
  startup. When an application attempts to lookup a WebSphere MQ
  JNDI resource it is thrown an exception with message WMSG2002E
  or WMSG2003E.
  A second restart of the application servers is required in
  order for applications to be able to lookup WebSphere MQ
  messaging provider JNDI resources and perform messaging.
  

Local fix

• Manually run osgiCfgInit between shutdown and startup of the
  application server.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of WebSphere Application Server V7.0   *
  *                 using WebSphere MQ as a messaging provider   *
  ****************************************************************
  * PROBLEM DESCRIPTION: Some changes made to an external        *
  *                      WebSphere MQ installation when an       *
  *                      server is stopped require it to be      *
  *                      restarted twice                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  APAR PK60337 describes the behavior of an application server
  when changes are made to an external WebSphere MQ
  installation, or the MQ_INSTALL_ROOT WebSphere variable.
  This includes two circumstances where an additional restart of
  the application server is required for messaging applications
  to access WebSphere MQ JNDI resources:
  - The MQ_INSTALL_ROOT is changed while an application server
    is stopped.
  - A significant change is made to the WebSphere MQ
    installation that adds a new Java or native library while
    an application server is stopped.
  This is due to an OSGi cache (shared between all servers in a
  profile) which is written when a server shuts down and
  contains information about the WebSphere MQ installation.
  
  The behavior means that a WebSphere Application Server
  administrator may need to be aware of changes to an external
  WebSphere MQ installation (or check for WMSG1612E or
  WMSG1614E log entries during startup of an application server)
  in order to ensure that applications can use WebSphere MQ JNDI
  resources after the application server is started.
  
  A workaround is to always run the osgiCfgInit script before
  starting any WebSphere processes on a node, as this clears the
  complete contents of the OSGi cache (including the information
  about the WebSphere MQ installation).
  

Problem conclusion

• This APAR adds the following new WebSphere variable
  Name:         MQ_CLEAR_MQ_FROM_OSGI_CACHE_ON_SHUTDOWN
  Valid values: true / false (default)
  Valid scopes: Cell or Node (do not customize at Server scope)
  
  With this variable set to "true", information about a
  WebSphere MQ installation will be removed from the OSGi cache
  of a node during server shutdown. This means that application
  servers can automatically respond to any type of change made
  to an external WebSphere MQ installation, or the
  MQ_INSTALL_ROOT variable, without an additional restart.
  
  If this variable is not set, the default behavior (described in
  APAR PK60337) remains unchanged.
  
  Startup time for application servers may increase with the
  variable set as additional processing is required to build the
  information that was previously saved to the OSGi cache.
  
  APAR PK75900 requires changes to documentation.
  
  NOTE: Periodically, we refresh the documentation on our
  Web site, so the changes might have been made before you
  read this text. To access the latest on-line
  documentation, go to the product library page at:
  
  http://www.ibm.com/software/webservers/appserv/library
  
  Changes to the WebSphere Application Server Version 6.1
  Information Center will be made available in
  December, 2008.
  
  The following optional step will be added to the
  "InstallingWebSphere MQ to interoperate with WebSphere
  Application Server" topic:
  
  Step 4 (optional). At Cell scope or Node scope, set the
  WebSphere Application Server
  MQ_CLEAR_MQ_FROM_OSGI_CACHE_ON_SHUTDOWN environment
  variable to True.
  
  This allows application server startup to automatically
  take account of changes that are made to the
  MQ_INSTALL_ROOT environment variable and WebSphere MQ JMS
  client libraries while the application server is stopped.
  
  If you do not set this variable, you must restart the
  application server a second time after any changes of
  this type, to enable the application to perform messaging
  using the WebSphere MQ messaging provider.
  
  Note: If you set the MQ_CLEAR_MQ_FROM_OSGI_CACHE_ON_SHUTDOWN
  environment variable, the startup time might increase
  because, on startup, each application server needs to
  initialize an additional state associated with WebSphere
  MQ installation.
  
  APAR PK75900 is currently targeted for inclusion in Service
  Level (Fix Pack) 7.0.0.1 of WebSphere Application Server V7.0
  for z/OS.
  
  Please refer to URL:
  //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
  for Fix Pack availability.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  PK71476

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• BBGUBINF BBOUBINF
  

Fix information

• Fixed component name

  WEBSPHERE FOR Z

• Fixed component ID

  5655I3500

Applicable component levels

• R700 PSY UK41764

     UP08/12/05 P F812

Fix is available

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