Understanding WebSphere MQ file names

Each WebSphere MQ queue, queue manager, namelist, and process object 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 default path to a queue manager directory is as follows:

• A prefix, which is defined in the WebSphere MQ configuration information:
  • In WebSphere MQ for Windows, the default prefix is C:\Program Files\IBM\WebSphere MQ. Use the WebSphere MQ Services snap-in if you want to change this. It is set on the All Queue Managers page of the WebSphere MQ properties.
  • In WebSphere MQ for UNIX systems, the default prefix is /var/mqm. You can change this in the DefaultPrefix stanza of the mqs.ini configuration file.

• The queue manager name is transformed into a valid directory name. For example, the queue manager:

  queue.manager
  

  would be represented as:

  queue!manager
  

  This process is referred to as name transformation.

Queue manager name transformation

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

For example, you could name a queue manager:

QUEUE.MANAGER.ACCOUNTING.SERVICES

However, each queue manager is represented by a file and there are limitations on the maximum length of a file name, and on the characters that can be used in the name. As a result, the names of files representing objects are automatically transformed to meet the requirements of the file system.

The rules governing the transformation of a queue manager name are as follows:

1. Transform individual characters:

   . becomes !

   / becomes &

2. If the name is still not valid:
   1. Truncate it to eight characters
   2. Append a three-character numeric suffix

For example, assuming the default prefix and a queue manager with the name queue.manager:

• In WebSphere MQ for Windows with NTFS or FAT32, the queue manager name becomes:

  c:\Program Files\IBM\WebSphere MQ\qmgrs\queue!manager
  

• In WebSphere MQ for Windows with FAT, the queue manager name becomes:

  c:\Program Files\IBM\WebSphere MQ\qmgrs\queue!ma
  

• In WebSphere MQ for UNIX systems, the queue manager name becomes:

  /var/mqm/qmgrs/queue!manager
  

The transformation algorithm also distinguishes between names that differ only in case on file systems that are not case sensitive.

Object name transformation

Object names are not necessarily valid file system names. You might need to transform your object names. The method used is different from that for queue manager names because, although there are only a few queue manager names on each machine, there can be a large number of other objects for each queue manager. 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 dspmqfls command to convert between real and transformed object names.