Channel initiator

This might affect Task 12 in Customizing your queue managers.

The queue SYSTEM.CHANNEL.REPLY.INFO is no longer used.

A process definition is no longer required if you want channels to start automatically when messages arrive on the transmission queue.

The value returned by the CONNAME attribute of the DISPLAY CHSTATUS command has changed. It is now always the connection name; a new attribute RQMNAME reports the remote queue manager name.

The size of channel objects was increased for Version 5.3 to allow for the added Secure Sockets Layer (SSL) channel attributes. WebSphere MQ automatically updates each of these SSL channel objects the first time that it is changed. This happens whether you are using SSL or not. However, due to the nature of space reclamation in WebSphere MQ, the space used on page set zero might increase dramatically until all these channel objects have been updated.

To avoid this, run a job on your V5.3.1 queue manager similar to that in Figure 33 that changes all your channel objects, enabling WebSphere MQ to update them all at the same time. This job will display channels and then use the output from this display to define replacement channels. The Channel initiator must be stopped when running this job.

Multiple channel exits are now supported. A channel auto-definition exit program could change the message, send and receive exits associated with a channel, and the user data associated with the exits, by altering the MsgExit, MsgUserData, SendExit, SendUserData, ReceiveExit and ReceiveUserData fields of the MQCD. If you have such an exit, change it to alter the fields addressed by MsgExitPtr, MsgUserDataPtr, SendExitPtr, SendUserDataPtr, ReceiveExitPtr and ReceiveUserDataPtr in the MQCD instead. The fields in the MQCD are described in WebSphere MQ Intercommunication.

Figure 33. Example job for migrating channel objects

//STEP1    EXEC  PGM=CSQUTIL,PARM='CSQ1'
//STEPLIB  DD    DISP=SHR,DSN=thlqual.SCSQANLE
//         DD    DISP=SHR,DSN=thlqual.SCSQAUTH
//OUTPUT1  DD    DISP=OLD,DSN=MY.COMMANDS(DEFS)
//SYSPRINT DD    SYSOUT=*
//SYSIN    DD    *
COMMAND DDNAME(CMDINP) MAKEDEF(OUTPUT1)
/*
//CMDINP   DD *
DISPLAY CHANNEL(*) ALL
/*
//*   STEP2
//***********************************************************************
//* PERFORM A GLOBAL CHANGE ON THE OUTPUT DATA SET FROM STEP 1, THAT    *
//* IS: MY.COMMANDS(DEFS).  CHANGE 'NOREPLACE' TO 'REPLACE'             *
//* THE CHANGED MY.COMMANDS(DEFS) WILL BE THE INPUT FOR STEP3.          *
//***********************************************************************
//*
//STEP3    EXEC  PGM=CSQUTIL,PARM='CSQ1'
//STEPLIB  DD    DISP=SHR,DSN=thlqual.SCSQANLE
//         DD    DISP=SHR,DSN=thlqual.SCSQAUTH
//SYSPRINT DD    SYSOUT=*
//SYSIN    DD    *
COMMAND DDNAME(DEFINES)
/*
//***********************************************************************
//* THE DEFINE COMMAND FOR THE SYSTEM.COMMAND.INPUT QUEUE MIGHT FAIL,   *
//* BUT THIS DOES NOT MATTER. ALTERNATIVELY, REMOVE THE DEFINE FOR THAT *
//* QUEUE FROM THE OBJECT DATA SET FROM STEP 1.                         *
//***********************************************************************
//*
//DEFINES  DD DISP=SHR,DSN=MY.COMMANDS(DEFS)

Existing channels have the following values set for the new attributes added in V5.3:

KAINT	AUTO
LOCLADDR	blank
BATCHHB	zero
SSLPEER	blank
SSLCIPH	blank
SSLCAUTH	REQUIRED
Extra exit names	blank
Extra user data	blank

In previous versions of the product, a channel auto-definition exit program could change the message, send and receive exits associated with a channel, and the user data associated with the exits, by altering the MsgExit, MsgUserData, SendExit, SendUserData, ReceiveExit and ReceiveUserData fields of the MQCD. However, now that multiple channel exits are supported, a channel auto-definition exit program must alter the fields addressed by MsgExitPtr, MsgUserDataPtr, SendExitPtr, SendUserDataPtr, ReceiveExitPtr and ReceiveUserDataPtr in the MQCD. The fields in the MQCD are described in WebSphere MQ Intercommunication