Configuring client connection to a IBM MQ Appliance queue manager using Client Channel Definition Table (CCDT) - Middleware News

Queue manager stores the client connection channel information in client channel definition table (CCDT). This table is updated whenever a client connection channel is defined or altered.  MQ client applications uses the client channel definition table (CCDT) to determine the channel definitions and authentication information to connect to a queue manager.  For a client application to use the CCDT , it must either be copied to the client machine or the file should be placed in a location from where the client can access it. However, there is no traditional file system available on the appliance. Hence the file needs to be copied to a directory from where it can be downloaded. 

Here are the steps to do it.

Run the below command on the appliance to create the required MQ objects and a user account under which the client connection will be established.

usercreate -u maya -p passw0rd

crtmqm QM1

strmqm QM1

runmqsc QM1

    DEFINE QLOCAL(‘Q1’)

    DEFINE CHANNEL(‘CLNTCHL’) CHLTYPE(SVRCONN) TRPTYPE(TCP)

    DEFINE CHANNEL(‘CLNTCHL’) CHLTYPE(CLNTCONN) QMNAME(‘QM1’) CONNAME(‘_ADDRESS>(2323)’) TRPTYPE(TCP)

    DEFINE LISTENER(‘L1’) TRPTYPE(TCP) PORT(2323)

    START LISTENER(‘L1’)

    END

Set channel authentication rule to accept connection from the IP address of your client system

    SET CHLAUTH ('CLNTCHL') TYPE(ADDRESSMAP) ADDRESS(9.109.242.213) MCAUSER('maya')

Grant access to the user account ‘maya’ so that it can connect to and inquire the queue manager and also has the authority to put , get , inq and browse the queue Q1

   SET AUTHREC OBJTYPE(QMGR) PRINCIPAL('maya') AUTHADD(CONNECT,INQ)

   SET AUTHREC PROFILE('Q1') OBJTYPE(QUEUE) PRINCIPAL('maya') AUTHADD(PUT,GET,INQ,BROWSE)

Steps to download CCDT to a client machine:

In order to download the CCDT to the client machine, it must be first copied to a location from where the file can be downloaded.

• Run the following command on the appliance to generate the AMQCLCHL.TAB file in the      mqbackup:// URI.

rcrmqobj –m QM1 –t clchltab

This command creates a file with name rName>_AMQCLCHL.TAB in the mqbackup:// URI.

Example:

QM1_AMQCLCHL.TAB

Use webui  to download the CCDT file to the client machine to the directory of your choice.

Steps to run a sample application using the downloaded CCDT in client machine:

• On the windows client machine set the MQSAMP_USER_ID environment variable to identify the user that is running the sample programs
• set MQCHLLIB and MQCHLTAB environment variables to specify the location and name of the CCDT respectively.

Example:

Alternatively, client channel definition table can be generated on the MQ client machine by using runmqsc client.  

Create CLNTCONN channel definition on the client machine by using runmqsc command with –n option.

Example:

runmqsc -n

   DEFINE CHANNEL(‘CLNTCHL’) CHLTYPE(CLNTCONN) QMNAME(‘QM1’) CONNAME(‘_ADDRESS>(2323)’) TRPTYPE(TCP)

   END

The above command creates a channel definition table file in the MQ data directory. On Linux the default location is /var/mqm and on windows the default location is C:\ProgramData\IBM\MQ. This file can then be used for connecting to the appliance queue manager.