Understanding IBM MQ for IBM i queue manager library names

Use this information to understand library names, IFS directories, and name transformation.

When a queue manager is created, IBM® MQ associates a queue manager library with it. This queue manager library is given a unique name, no more than 10 characters long, largely based on the user defined queue manager name. Both the queue manager, and the queue manager library are placed in to a directory that is also based on the queue manager name with the prefix /QIBM/UserData/mqm. An example of a queue manager, queue manager library, and directory follows:
All queue manager names and queue manager library names are written to stanzas in the file /QIBM/UserData/mqm/mqs.ini.

Understanding IBM MQ IFS directories and files

The IBM i Integrated File System (IFS) is used extensively by IBM MQ to store data. For more information about the IFS see the Integrated File System Introduction.

Each IBM MQ object (for example: channels or queue managers) is represented by a file. Because object names are not necessarily valid file names, the queue manager converts the object name into a valid file name where necessary.

The path to a queue manager directory is formed from the following:
  • A prefix, which is defined in the queue manager configuration file, qm.ini. The default prefix is /QIBM/UserData/mqm.
  • A literal, qmgrs.
  • A coded queue manager name, which is the queue manager name transformed into a valid directory name. For example, the queue manager queue/manager is represented by queue&manager.

This process is referred to as name transformation.

IFS queue manager name transformation

In IBM MQ, you can give a queue manager a name containing up to 48 characters.

For example, you can name a queue manager QUEUE/MANAGER/ACCOUNTING/SERVICES. In the same way that a library is created for each queue manager, each queue manager is also represented by a file. Because of variant codepoints in EBCDIC, there are limitations to the characters that can be used in the name. As a result, the names of IFS files representing objects are automatically transformed to meet the requirements of the file system.

Using the example of a queue manager with the name queue/manager, transforming the character / to &, and assuming the default prefix, the queue manager name in IBM MQ for IBM i becomes /QIBM/UserData/mqm/qmgrs/queue&manager.

Object name transformation

Object names are not necessarily valid file system names, so the object names might need to be transformed. The method used is different from that for queue manager names because, although there only a few queue manager names for each machine, there can be a large number of other objects for each queue manager. Only process definitions, queues, and namelists are represented in the file system; channels are not affected by these considerations.

When a new name is generated by the transformation process, there is no simple relationship with the original object name. You can use the DSPMQMOBJN command to view the transformed names for IBM MQ objects.