WebSphere Message Brokers
File: ac00905_
Writer: Laura Cowen

Task topic

This build: July 31, 2007 21:16:59

Configuring global coordination with DB2 using a 64-bit queue manager

To globally coordinate message flow transactions with updates in DB2 databases, configure the broker environment. This topic describes how to configure the broker environment when the broker uses a 64-bit queue manager.

Before you start:

All WebSphere MQ Version 6 queue managers on 64-bit platforms are 64-bit. 64-bit queue managers can coordinate transactions only in 64-bit mode. If the broker uses a 64-bit queue manager, you can globally coordinate message flows that are deployed to either 64-bit or 32-bit execution groups, but if you are using 32-bit execution groups you must define the data source name of the user database in both odbc.ini and odbc64.ini. If the broker uses a 64-bit queue manager or has a 64-bit execution group, the databases to which the broker connects must be 64-bit too.

To configure your broker environment for global coordination using a 64-bit queue manager as the transaction manager:

  1. Decide whether the broker will connect to databases using TCP/IP or using shared memory.

    For more information about TCP/IP connections, see the example in the section about message SQL1224N in Resolving problems when using databases.

    To enable shared memory:

    1. Stop the broker by running the following command, where broker is the name of your broker:
      mqsistop broker
    2. Run the following command to ensure that the broker is run in an environment with the extended memory variable exported:
      export EXTSHM=ON
    3. Restart the broker by running the following command, where broker is the name of your broker:
      mqsistart broker
    4. On the DB2 server, ensure that shared memory support is turned on. For more information, see Configuring databases for global coordination of transactions.
  2. Follow the instructions appropriate to your execution groups:

32-bit execution groups

To configure the broker's queue manager to coordinate message flows that are deployed to a 32-bit execution group:
  1. On Linux (x86 platform) and UNIX only, create the following symbolic links to specify the location of the ODBC database drivers and switch file that are supplied with WebSphere Message Broker (on Linux, create only the first symbolic link shown):
    ln –s install_dir/sample/xatm/db2swit /var/mqm/exits/db2swit
    ln –s install_dir/sample/xatm/db2swit64 /var/mqm/exits64/db2swit
    Where:
    • install_dir is the location in which WebSphere Message Broker is installed.
  2. Configure the broker's queue manager with XA Resource Manager information for each database that is involved in the transaction that the queue manager will globally coordinate. If the message flows reference message dictionaries or contain Publication nodes, you must use the same method to define XA Resource Manager information for the broker database as well as for the user databases.

    On Linux (x86 platform) and UNIX:

    1. Open the queue manager's qm.ini file in a text editor. The qm.ini file is located at /var/mqm/qmgrs/queue_manager_name/qm.ini, where queue_manager_name is the name of the broker that is associated with the queue manager.
    2. At the end of the qm.ini file, paste the following stanza:
      XAResourceManager:
      Name=DB2
      SwitchFile=db2swit
      XAOpenString=db=MyDataSource,uid=MyUserId,pwd=MyPassword,toc=t
      XACloseString=
      ThreadOfControl=THREAD

      The switch file is supplied by WebSphere Message Broker.

    3. On the XAOpenString line, replace the following values with values that are appropriate for your configuration:
      • MyDataSource is the name of the data source to which you want to connect.
      • MyUserId must be the user name that is used by the broker to connect to the database. The user name was defined using the -u flag on the mqsicreatebroker command when creating the broker. If the -u parameter was not specified, the data source user name is the same as the broker's service user name, which was defined using the -i flag on the mqsicreatebroker command.
      • MyPassword is the password associated with the user name.
    4. Accept the default values for all the other lines in the stanza. For example:
      XAResourceManager:
      Name=DB2
      SwitchFile=db2swit
      XAOpenString=db=MYDB,uid=wbrkuid,pwd=wbrkpw,toc=t
      XACloseString=
      ThreadOfControl=THREAD
    On Windows:
    1. From the Start menu, open the WebSphere MQ Explorer graphical administration tool.
    2. Open the queue manager's Properties dialog, then open the XA resource managers page.
    3. In the SwitchFile field, enter the full path to the switch file, as shown in the following example where install_dir is the location in which the broker is installed:
      install_dir\sample\xatm\db2swit
    4. In the XAOpenString field, paste the following string:
      db=MyDataSource,uid=MyUserId,pwd=MyPassword,toc=t
    5. In the XAOpenString field, replace the values as appropriate for your configuration:
      • install_dir is the location in which the WebSphere Message Broker instance is installed.
      • MyDataSource is the name of the data source to which you want to connect.
      • MyUserId must be the user name that is used by the broker to connect to the database. The user name was defined using the -u flag on the mqsicreatebroker command when creating the broker. If the -u parameter was not specified, the data source user name is the same as the broker's service user name, which was defined using the -i flag on the mqsicreatebroker command.
      • MyPassword is the password associated with the user name.
      For example:
      db=MYDB,uid=wbrkuid,pwd=wbrkpw,toc=t
    6. Accept the default values for all the other fields on the page.
  3. Stop then restart the queue manager to apply the changes because qm.ini is read only when the queue manager starts.
    To stop then restart the queue manager, enter the following commands, where queue_manager_name is the name of the queue manager:
    endmqm queue_manager_name
    strmqm queue_manager_name

    When the queue manager restarts, check the queue manager's log for any warnings that are associated with the restart. The log files are located in /var/mqm/qmgrs/queue_manager_name/errors, where queue_manager_name is the name of the queue manager that you restarted.

    When the queue manager restarts successfully, the changes that you made to qm.ini are applied.
DB2 is now configured for global coordination with a 64-bit queue manager coordinating transactions.
Now, you can deploy globally coordinated message flows to the broker.

64-bit execution groups

To configure the broker's queue manager to coordinate message flows that are deployed to a 64-bit execution group:
  1. On UNIX only, create the following symbolic links to specify the location of the ODBC database drivers and switch file that are supplied with WebSphere Message Broker:
    ln –s install_dir/sample/xatm/db2swit64 /var/mqm/exits64/db2swit
    ln -s install_dir/sample/xatm/db2swit /var/mqm/exits/db2swit
    Where:
    • install_dir is the location in which WebSphere Message Broker is installed.
  2. Configure the broker's queue manager with XA Resource Manager information for each database that is involved in the transaction that the queue manager will globally coordinate. If the message flows reference message dictionaries or contain Publication nodes, you must use the same method to define XA Resource Manager information for the broker database as well as for the user databases.

    On UNIX:

    1. Open the queue manager's qm.ini file in a text editor. The qm.ini file is located at /var/mqm/qmgrs/queue_manager_name/qm.ini, where queue_manager_name is the name of the broker that is associated with the queue manager.
    2. At the end of the qm.ini file, paste the following stanza:
      XAResourceManager:
      Name=DB2
      SwitchFile=db2swit
      XAOpenString=db=MyDataSource,uid=MyUserId,pwd=MyPassword,toc=t
      XACloseString=
      ThreadOfControl=THREAD

      The switch file is supplied by WebSphere Message Broker.

    3. On the XAOpenString line, replace the following values with values that are appropriate for your configuration:
      • MyDataSource is the name of the data source to which you want to connect.
      • MyUserId must be the user name that is used by the broker to connect to the database. The user name was defined using the -u flag on the mqsicreatebroker command when creating the broker. If the -u parameter was not specified, the data source user name is the same as the broker's service user name, which was defined using the -i flag on the mqsicreatebroker command.
      • MyPassword is the password associated with the user name.
    4. Accept the default values for all the other lines in the stanza. For example:
      XAResourceManager:
      Name=DB2
      SwitchFile=db2swit
      XAOpenString=db=MYDB,uid=wbrkuid,pwd=wbrkpw,toc=t
      XACloseString=
      ThreadOfControl=THREAD
  3. Stop then restart the queue manager to apply the changes because qm.ini is read only when the queue manager starts.
    To stop then restart the queue manager, enter the following commands, where queue_manager_name is the name of the queue manager:
    endmqm queue_manager_name
    strmqm queue_manager_name

    When the queue manager restarts, check the queue manager's log for any warnings that are associated with the restart. The log files are located in /var/mqm/qmgrs/queue_manager_name/errors, where queue_manager_name is the name of the queue manager that you restarted.

    When the queue manager restarts successfully, the changes that you made to qm.ini are applied.
DB2 is now configured for global coordination with a 64-bit queue manager coordinating transactions.
Now, you can deploy globally coordinated message flows to the broker.
Related reference
Supported databases
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This build: July 31, 2007 21:16:59

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