This section covers the following topics:
To configure Natural Messaging, specific Natural parameters must be defined in the Natural parameter module. This parameter module should be customized to meet your site's standards, then assembled and linked using the appropriate installation jobs.
For installation instructions, see Installing Natural Messaging in the Installation for z/OS documentation.
To access messaging resources such as IBM MQ queues, Natural Messaging requires that a
dedicated database ID (DBID) is defined as database type MQ . This logical
assignment maps the DBID to the MQ database type, allowing Natural programs
to interact with message queues through DDMs defined for IBM MQ queues.
This setup can be done in either of the following ways:
Statically, using the NTDB macro in the Natural parameter module.
Example:
NTDB MQ, mq-dbid
Dynamically, using the profile parameter DB.
Example:
DB=(MQ, mq-dbid)
Notes:
NTDB macro for Natural
Messaging does not conflict with DBIDs assigned to other database management systems.
This helps prevent misrouting and access issues in environments where multiple DBMS
types are used.
MQ queue DDMs used in Natural applications must be associated
with the same DBID defined in the NTDB macro or the DB
parameter. This ensures consistent and correct access to messaging resources
throughout the application.
The provided DDM MQ-QUEUE enables Natural applications to interface with IBM
MQ message queues. To integrate this DDM into a customer-specific environment, its DBID
may need to be updated to match the DBID defined for messaging in your system
configuration.
Before updating the DDM, ensure that the required DBID is properly configured as described in Defining the Database Type and Database ID (DBID).
Start a Natural session and invoke the SYSDDM utility.
Select the Read function (code R) and enter MQ-QUEUE as the
DDM name. This loads the DDM into the source area.
Change the DBID field to the required value to match your environment.
Use the CATALOG REPLACE command to save the updated DDM.
Once modified, the MQ-QUEUE DDM will be aligned with your Natural
Messaging DBID, ensuring correct integration with your messaging setup.
Note
For more information, see SYSDDM
Utility in the Editors documentation or
contact support.
To support larger message payloads in Natural Messaging, you may need to adjust the
length of the MESSAGE field in the MQ-QUEUE DDM. Proceed as
follows:
Launch the SYSDDM utility in your Natural session.
Select the Edit function (code E) and enter MQ-QUEUE as the
DDM name.
In the field list, locate the MESSAGE field (typically an alphanumeric
field named MESSAGE (MG)).
Update the field length to match the maximum message size required by your application.
Note
If your message content may exceed 253 characters, change the MESSAGE
field using the LB (large binary) format instead of a standard
A (alphanumeric) field. This enables support for large message payloads
beyond the conventional field limits.
After making changes, use the CHECK command to validate the DDM,
followed by CATALOG REPLACE to save the changes. The updated DDM will now
support larger or customized MQ message sizes at runtime, ensuring compatibility with
your messaging workload.
When retrieving messages from MQ, both the message data and the internal MQ buffer are stored within the Natural thread.
Insufficient thread size can lead to runtime errors. To prevent these issues, adjust the Natural thread size parameters to safely accommodate larger MQ payloads.
For details on configuring thread size, see the THSIZE parameter in the Parameter
Reference.