| Common Information Model | |
| Status: | Published |
| Organization: | Distributed Management Task Force |
| Related Standards: | WBEM and SMASH |
| Abbreviation: | CIM |
| Domain: | Information model |
The Common Information Model (CIM) is an open standard that defines how managed elements in an IT environment are represented as a common set of objects and relationships between them.
The Distributed Management Task Force maintains the CIM to allow consistent management of these managed elements, independent of their manufacturer or provider.
One way to describe CIM is to say that it allows multiple parties to exchange management information about these managed elements. However, this falls short of fully capturing CIM's ability not only to describe these managed elements and the management information, but also to actively control and manage them. By using a common model of information, management software can be written once and work with many implementations of the common model without complex and costly conversion operations or loss of information.
The CIM standard is defined and published by the Distributed Management Task Force (DMTF). A related standard is Web-Based Enterprise Management (WBEM, also defined by DMTF) which defines a particular implementation of CIM, including protocols for discovering and accessing such CIM implementations.
The CIM standard includes the CIM Infrastructure Specification and the CIM Schema:
The CIM Infrastructure Specification defines the architecture and concepts of CIM, including a language by which the CIM Schema (including any extension schema) is defined, and a method for mapping CIM to other information models, such as SNMP. The CIM architecture is based upon UML, so it is object-oriented: The managed elements are represented as CIM classes and any relationships between them are represented as CIM associations. Inheritance allows specialization of common base elements into more specific derived elements.
The CIM Schema is a conceptual schema which defines the specific set of objects and relationships between them that represent a common base for the managed elements in an IT environment. The CIM Schema covers most of today's elements in an IT environment, for example computer systems, operating systems, networks, middleware, services and storage. Classes can be, for example: CIM_ComputerSystem, CIM_OperatingSystem, CIM_Process, CIM_DataFile. The CIM Schema defines a common basis for representing these managed elements. Since most managed elements have product and vendor specific behavior, the CIM Schema is extensible in order to allow the producers of these elements to represent their specific features seamlessly together with the common base functionality defined in the CIM Schema.
Updates to the CIM Schema are published regularly.[1]
CIM is the basis for most of the other DMTF standards (e.g. WBEM or SMASH). It is also the basis for the SMI-S standard for storage management.
Many vendors provide implementations of CIM in various forms:
There is also a growing number of tools market around CIM.[3]
Standards organizations have defined management standards based on the CIM Schema:
A number of protocols are defined for messages transmitted between clients and servers. The message protocols are transmitted on top of HTTP. There are two message types:
CIM-XML forms part of the WBEM protocol family, and is standardised by the DMTF.
CIM-XML comprises three specifications:
WS-MAN forms part of the WBEM protocol family, and is standardised by the DMTF.
WS-MAN comprises 3 specifications:
CIM-RS forms part of the WBEM protocol family, and is standardised by the DMTF.
CIM-RS comprises three specifications: