Common Information Model (computing)


The Common Information Model 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.

Overview

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 in expressing that CIM not only represents these managed elements and the management information, but also provides means to actively control and manage these elements. 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. A related standard is Web-Based Enterprise Management which defines a particular implementation of CIM, including protocols for discovering and accessing such CIM implementations.

Schema and specifications

The CIM standard includes the CIM Infrastructure Specification and the CIM Schema:
CIM is the basis for most of the other DMTF standards. It is also the basis for the SMI-S standard for storage management.

Implementations

Infrastructure Implementations

Many vendors provide implementations of CIM in various forms:
There is also a growing number of tools market around CIM.

Management Standards based on the CIM Schema

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:
  1. operational messages, which provoke a response from the receiver
  2. export messages, which are indications/events.

    CIM Operations over HTTP (CIM-XML)

CIM-XML forms part of the WBEM protocol family, and is standardised by the DMTF.
CIM-XML comprises three specifications:
  1. CIM Operations over HTTP
  2. Representation of CIM using XML
  3. CIM DTD

    WS-Management

WS-MAN forms part of the WBEM protocol family, and is standardised by the DMTF.
WS-MAN comprises 3 specifications:
  1. WS-CIM Mapping Specification
  2. WS-Management CIM Binding Specification
  3. Web Services for Management Specification

    CIM operations over RESTful services

CIM-RS forms part of the WBEM protocol family, and is standardised by the DMTF.
CIM-RS comprises three specifications:
  1. CIM Operations Over RESTful Services
  2. CIM-RS Protocol Specification
  3. CIM-RS Payload Representation in JSON