Initialization and configuration files

The handling of channel initialization data depends on the IBM MQ platform.

z/OS systems

In IBM MQ for z/OS, initialization and configuration information is specified using the ALTER QMGR MQSC command. If you put ALTER QMGR commands in the CSQINP2 initialization input data set, they are processed every time the queue manager is started.

To run MQSC commands such as START LISTENER every time you start the channel initiator, put them in the CSQINPX initialization input data set and specify the optional DD statement CSQINPX in the channel initiator started task procedure.

For further information about CSQINP2 and CSQINPX, see Customize the initialization input data sets, and ALTER QMGR.

Windows, IBM i, UNIX and Linux systems

In IBM MQ for Windows, IBM i, UNIX and Linux systems, there are configuration files to hold basic configuration information about the IBM MQ installation.

There are two configuration files: one applies to the machine, the other applies to an individual queue manager.

IBM MQ configuration file

This file holds information relevant to all the queue managers on the IBM MQ system. The file is called mqs.ini. It is fully described in the Administer for IBM MQ for Windows, and in Administer IBM i , and in UNIX and Linux systems.

Queue manager configuration file

This file holds configuration information relating to one particular queue manager. The file is called qm.ini.

It is created during queue manager creation and can hold configuration information relevant to any aspect of the queue manager. Information held in the file includes details of how the configuration of the log differs from the default in the IBM MQ configuration file.

The queue manager configuration file is held in the root of the directory tree occupied by the queue manager. For example, for the DefaultPath attributes, the queue manager configuration files for a queue manager called QMNAME would be:

For UNIX and Linux systems:

/var/mqm/qmgrs/QMNAME/qm.ini

An excerpt of a qm.ini file follows. It specifies that the TCP/IP listener is to listen on port 2500, the maximum number of current channels is to be 200, and the maximum number of active channels is to be 100.

TCP:
Port=2500
CHANNELS:
MaxChannels=200
MaxActiveChannels=100

We can specify a range of TCP/IP ports to be used by an outbound channel. One method is to use the qm.ini file to specify the start and end of a range of port values. The following example shows a qm.ini file specifying a range of channels:

TCP:
StrPort=2500
EndPort=3000
CHANNELS:
MaxChannels=200
MaxActiveChannels=100

If you specify a value for StrPort or EndPort then you must specify a value for both. The value of EndPort must always be greater than the value of StrPort.

The channel tries to use each of the port values in the range specified. When the connection is successful, the port value is the port that the channel then uses.

For IBM i:

/QIBM/UserData/mqm/qmgrs/QMNAME/qm.ini

For Windows systems:

C:\ProgramData\IBM\MQ\qmgrs\QMNAME\qm.ini

For more information about qm.ini files, see Configuration file stanzas for distributed queuing.

Parent topic: Introduction to distributed queue management