Registration

A resource manager must register every time it is started, regardless of whether the start is caused by failure of the system or the resource manager itself. If an exit manager fails, however, the resource manager does not need to register again, though it does have to call Set_Exit_Information to reidentify itself and to reset the exits for the exit manager that failed.

Registration is the same when starting for the first time, restarting after a normal shut down, or restarting after a failure. The sequence is:

Call the Register_Resource_Manager service.
Call the Set_Exit_Information service one or more times to identify the resource manager to appropriate exit managers and to identify all of the resource manager's exit routines.

In the call to the Register_Resource_Manager service, the resource manager identifies itself with a unique 32-byte name. Registration services checks whether or not the name is already registered on the current system; the check does not include other systems in the sysplex. If the name is not registered, registration services registers it and returns a 16-byte resource manager token. This token represents the resource manager and is required on many calls. The resource manager token is a random value that is not preserved across a restart of the system, exit manager, or resource manager. Thus:

Do not use the resource manager token as an identifier in log records.
Do not try to discern the contents of the token or create any dependencies on the contents.