IMS components and system services that are part of an IMSplex
An IMSplex can include several different IMS components: IMS subsystems, DBRC and RECON data sets, IMS Connect, and TSO SPOC. IMS uses IRLM for lock services.
In addition, a number of IMS address spaces provide system services in an IMSplex. These address spaces are all built using the Base Primitive Environment (BPE), which provides system services such as tracing, message formatting, parsing, storage management, sub-dispatching, and serialization.
The BPE system services are used by the Common Queue Server (CQS), and the CSL's Open Database Manager (ODBM), Operations Manager (OM), Resource Manager (RM), Structured Call Interface (SCI), Repository Server (RS), and, optionally, the Database Recovery Control facility (DBRC), each of which contributes other system services:
- Common Queue Server
- Receives, maintains, and distributes data objects from shared queues.
- Common Service Layer
- Includes the following components:
- Open Database Manager
- Provides access to IMS databases managed by IMS DB systems in DBCTL and DB/TM environments within an IMSplex. ODBM supports TCP/IP clients through IMS Connect and application servers running application programs that use the IMS ODBA interface, such as Db2 for z/OS® or WebSphere® Application Server for z/OS.
- Operations Manager
- Routes commands, consolidates command responses, provides an API for command automation, and provides user exits for customization and security.
- Resource Manager
- Maintains global resource information, ensures resource consistency,
and coordinates IMSplex-wide processes such as global online change.
The RM also provides the interface for and access to the IMSRSC repository.
- Structured Call Interface
- Routes messages, registers and deregisters members of an IMSplex, provides security authentication of IMSplex members, and more.
- Repository Server
- Manages the IMSRSC repository, which is a data storage facility that can be used to store resource and descriptor definitions.
IMS also uses IRLM for lock services.