Model 204
V510: MQ/204 – Enhanced Power and Flexibility
By James Damon
This release of Model 204 includes significant enhancements to MQ/204, CCA’s API (Application Programming Interface) to IBM’s Websphere MQ family of products. Websphere MQ, formerly called MQSeries, supports messaging between applications running on different platforms under different operating systems. This statement is from the IBM website: http://www-3.ibm.com/software/ts/mqseries/
"WebSphere MQ, formerly MQSeries and the core of the WebSphere MQ family, integrates more than 35 platforms, provides the base messaging functions for servers and clients, and assures once only message delivery. It can be used alone or with other members of the family."
In March 1999, CCA announced the commercial release of V4R2 of Model 204 and, simultaneously, the release of MQ/204. In the March 1999 issue of CCAPRINT, under the title "Announcing MQ/204 – Uniting Model 204 and MQSeries" the following paragraphs appeared:
How MQSeries works
IBM’s MQSeries is a message queuing middleware product that provides an easy-to-use programming interface, and allows applications to exchange information freely and easily. In the simplest case, Application A puts a message on a queue, and Application B retrieves it. But depending on your application needs, the scenario could be far more complex, and involve multiple computers, multiple queues, and deferred messages.
How MQ/204 works
CCA’s MQ/204 is an intuitive extension to User Language that lets you take advantage of MQSeries from within Model 204. By simply learning a few new command parameters, programmers can modify User Language applications to send and receive messages using MQSeries’ queues.You can even use Model 204 variables and images in your MQSeries operations, and there’s no need to link to complex, external routines.
V510 - MQ/204 Enchanements
In this release we provide support for dynamic queues, permanent and temporary, which relieve system support staff of the task of defining queues prior to their use. We also provide support for run-time variables in MQ statements which we call ?%variables. This facility allows the application to change, dynamically at run-time, options, attributes and queue names in various User Language statements which provide access to Websphere MQ.
Dynamic queues
Prior to V510, Websphere MQ queues had to be defined by the MQ administrator before reference from a User Language-MQ/204 application could occur. Dynamic queues relieve the MQ administrator of this burden and allow the application to define queues only when required. Once the MQ administrator has defined a "model queue" to Websphere MQ, that model queue can be used by any application to create any number of dynamic queues. Multiple model queues with different attributes can be defined. The Websphere MQ starter system is installed with several model queues. One is named CSQ4IVP1.MODEL and has the attribute DEFTYPE=(PERMDYN) meaning that it is a model queue for a permanent, dynamic queue. The following User Language example uses this model queue to define a dynamic queue (a queue that is not defined at the start of application) named CCA.DYNQ01 and put ten messages on the queue with the MQPUT statement:
DEFINE Q CSQ4IVP1.MODEL WITH SCOPE=SYSTEM QM=CSQ1 START QM CSQ1 B %DYNQ IS STRING LEN 255 INITIAL ('CCA.DYNQ01') %MODQ IS STRING LEN 255 INITIAL ('CSQ4IVP1.MODEL') %MSG IS STRING LEN 255 * SUBROUTINE ERRORSUB (%CALL) PRINT %CALL WITH $STATUS AT 10 WITH $STATUSD AT 20 STOP END SUBROUTINE * OPEN QUEUE CCADYN1 DYNAMICQNAME=%DYNQ MODEL=%MODQ OUTPUT IF $STATUS NE 0 THEN CALL ERRORSUB('OPEN QUEUE') END IF FOR %I FROM 1 TO 10 %HDR = 'MSG' WITH %I %MSG = %HDR WITH ': ' WITH $TIME WITH ' @ ' WITH $DATE(1) MQPUT %MSG CCADYN1 IF $STATUS NE 0 THEN CALL ERRORSUB('MQPUT') END IF END FOR CLOSE QUEUE CCADYN1 END
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