PK71476: CHANGES MADE TO A WMQ INSTALLATION WHILE AN APPLICATION SERVER IS STOPPED CAN PREVENT APPS FROM USING MESSAGING AFTER STARTUP

Fixes are available

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 V6.1  *
*                  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 PK71476 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 PK71476 is currently targeted for inclusion in Service
Level (Fix Pack) 6.1.0.21 of WebSphere Application Server V6.1
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 number
PK71476
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-09-04
Closed date
2008-10-23
Last modified date
2008-12-02

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

PK75900

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R610 PSY UK41575
UP08/11/26 P F811 ½

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PK71476: CHANGES MADE TO A WMQ INSTALLATION WHILE AN APPLICATION SERVER IS STOPPED CAN PREVENT APPS FROM USING MESSAGING AFTER STARTUP

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R610 PSY UK41575

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

Document Information

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