Overview of the Resource Manager

RM helps you manage resources that are shared by multiple IMS systems in an IMSplex. RM provides the infrastructure for managing global resource information and coordinating IMSplex-wide processes, such as global online change.

RM provides the following functions to an IMSplex:

Maintains global resource information in a resource structure, which is a coupling facility list structure that all RMs in the IMSplex can access.
Ensures resource consistency so that a resource defined as a transaction, lterm, or msname is defined as the same resource type for all IMS systems in the IMSplex.
Supports resource services.
Supports client services.
Uses the Common Queue Server (CQS) to maintain global resource information.
Coordinates IMSplex-wide processes (such as global online change).

With RM, the system administrator can manage resources that are shared by multiple IMS systems in an IMSplex. RM provides an infrastructure for managing global resources and coordinating processes across the IMSplex.

Recommendation: Although a resource structure is optional in an IMSplex, define a resource structure for improved recovery capabilities. However, if you are using shared queues and you want to manage serial applications in an IMSplex, at least one RM must be active with a defined resource structure.

At least one RM must be defined in an IMSplex to use RM functions. You can have one or more RMs on each z/OS® image if a resource structure is defined. If no resource structure is defined, you can have only one RM. If you do not require RM functions, you can configure your IMS system without an RM, specifying RMENV=N on the DFSCGxxx PROCLIB member data set. Any RM can process work from any z/OS image within an IMSplex.