WLM Components
WLM consists of a number of major software components including:
SRM— System Resource Manager, referred to as SRM(IBM) in this document to differentiate it from the Solaris Resource Manager software. This component provides the algorithms for managing resources and caters to dynamic switching between compatibility and goal modes.
RMF— Resource Measurement Facility. Tracks metrics including progress against goals.
XCF— Cross-System Coupling Facility (Sysplex interconnect communications infrastructure). Communicates policies, metrics, and control data between Sysplex nodes.
ISPF— Interactive System Productivity Facility, a generic MVS interface that can be used to define, activate, and deactivate policies.
CP/SM—CICSPlex/System Manager— Acts as a Sysplex TPM by dynamically routing CICS queries to appropriate MVS nodes for both capability and response in line with goals.
These are all products that work together to dynamically manage performance and resources for components of IBM Sysplex systems. WLM is based on hierarchical control of resources. Thus each node within the Sysplex is responsible for managing its assigned share of the workload and communicates with the WLM to ensure that it is appropriately co-ordinated and meets the Sysplex wide goals. Also some sub-systems, specifically CP/SM effectively have delegated responsibility for managing the resources they are capable of controlling, in such a way as to ensure that goals are met.