CIM Tutorial

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CIM Tutorial

• Karl Quinn
• NDS 106, 7th December 2004.

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CIM Tutorial Overview

• CIM (Common Information Model)
• CIM Specification
• CIM Schema
• Managed Object Format (MOF) UML
• WBEM (Web Based Enterprise Mgt)
• Overview, Explanation, Benefits
• CIM Tools
• CIM Mine
• Comparison CIM v SNMP
• MOF v MIB

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CIM

• CIM is an implementation neutral schema for
  describing overall management information
• CIM facilitates the common understanding of
  management data across different management
  systems
• CIM facilitates the integration of management
  information from different sources
• CIM is a data model not an implementation
• CIM provides models for both instrumentation and
  management

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CIM

• CIM consists of three components
• (i) CIM Specification
• (ii) CIM Schema
• (iii) CIM Extension Schema
• CIM represents its information in Managed Object
  Format (MOF), which is analogous to MIB for SNMP.

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CIM Specification

• CIM Specification defines the details for
  integration with other management models.
• it is the language and methodology for
  describing management data.

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CIM Specification

• CIM Specification uses an object-oriented
  approach to describe each entity within a
  schemas area of concern.
• Ability to aggregate both attributes and
  behaviours within an entity as well as presenting
  the relationships and associations of that entity
  directly.

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CIM Specification

• The CIM Metaschema is responsible for a
  collection of classes, which are instances of
  objects of the same type.
• These objects contain attributes and method.
• Also references, which describe the role of an
  object within an Association. Associations
  provide containers for these references. NB
  Association are objects!
• References Associations ability to model
  relationships between a number of objects.

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CIM - Metaschema
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CIM Metaschema

• Triggers generate Indications when
  property/object changes state
• Qualifiers control sub-typing.
• Property Data Types include signed and unsigned
  integers, floats, and strings.
• Altering schema is via a set of 11 operations.

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CIM - MOF

• CIM defines the MOF language based on the
  Interface Definition Language to represent
  management information.
• The MOF syntax is a way to describe object
  definitions in textual form and it establishes
  the syntax for writing definitions.
• Main components of a MOF specification are
  classes, associations, properties, references,
  methods and instance declarations and their
  associated qualifiers.

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CIM - UML

• UML (Unified Mark-Up Language) can be used in
  place of MOF as a represent language.
• UML doesnt have all the functionality of MOF.
• UML doesnt present a CIM standard.

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CIM Schema

• CIM Schema
• Provides the actual model descriptions for
  systems, applications, local area networks, and
  devices.
• It is a set of classes and associations that
  provide a framework within which it is possible
  to organize the information about the managed
  environment
• CIM Schema consists of the following models
• (i) The Core Model
• (ii) The Common Model

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CIM Schema Core Model

• Core Model - Provides the underlying, general
  assumptions of the managed environment. This
  model comprises a small set of classes and
  associations that provide a basic vocabulary for
  analyzing and describing managed systems.

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CIM Schema Core Model
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CIM Schema Common Model

• Common Model
• Captures notions that are common to particular
  management areas, but which are independent of a
  particular technology or implementation.
• Provides detailed enough classes, properties,
  associations and methods to be used as a basis
  for program design development of management
  applications.
• Common Models
• Applications, Database, Devices, Network,
  Physical, Policy, etc.

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CIM Schema Common Model

• Policy Model
• Built in order to describe systems behaviour and
  to keep two main qualities
• (i) is that this model is abstracted enough not
  to deal with implementation details and
• (ii) is that it is easily scalable.
• The model is object-oriented and enables
  constructing policy rules of the form if
  conditions then actions.

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CIM Extension Schema

• Extension schema
• Represents technology and platform-specific
  extensions to the Common Model.
• Specific to environments such as operating
  systems. Vendors extend the model for their
  products by creating subclasses of objects.
• Applications can then transverse object instances
  in the standard model to manage different
  products in a heterogeneous environment.

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WBEM - Overview

• Web-Based Enterprise Management is a set of
  management and Internet standard technologies
  developed (by DMTF) to unify the management of
  enterprise computing environments.
• CIM operations over HTTP allows implementations
  of CIM to interoperate in an open and
  standardized manner.

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WBEM - Explanation
Data Description CIM
HTTP Access
lt/xmlCIMgtTransport Encoding
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xmlCIM

• Enables CIM declarations (Classes, Instances, and
  Qualifiers) and CIM messages to be described in
  an XML
• CIM classes and instances are valid XML documents
• Advantages
• Only one DTD need be defined
• Avoids limitations of DTDs (ordering,scoping,no
  inheritance)
• Straightforward

ltCLASS NameDiskgt ltPROPERTY NameFreespacegt 20
0 lt/PROPERTYgt lt/CLASSgt
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WBEM - Infrastructure
Provider- Implements classes from the CIM
schema. CIM Client/Server- Client issues
Operation Message Requests to server, which
responds with Operation Message Response. CIM
Object Manager- Co-ordinates communications
between various components. Protocol Adapter-
Converts CIM-XML messages to native
format. Indication Handler- Notification
mechanism for CIM data.
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WBEM - Benefits

• Reduced Total Cost of Ownership
• - less man-hours as a result of interoperability
• Improved Time to Market
• - standards based models
• Reduced Development Cost
• - reuse

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CIM Tools

• SNIAs (Storage Network Industry Association)
  CIM Miner.
• It mines a specified common interface model
  object manager namespace for instances and
  associations.
• It then stores the discovered information in an
  XML format file, which can be transformed into MOF

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CIM v SNMP - General

• SNMP popular because of its simplicity.
• Yet, this simplicity prohibited the definition of
  more complex data and relationships.
• CIM uses a rich syntax for representing
  management information and relationships between
  managed objects.

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CIM v SNMP - Models

• CIM schema object-oriented approach for
  describing the schema that management
  applications can use to communicate with each
  other.
• SNMP MIB is a hierarchical tree view of all
  managed objects.

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CIM v SNMP - Model Extension

• The OO CIM requires an understanding of the
  different parts of the CIM model as well as the
  relationships, attributes, methods for each class
  in the different CIM models.
• SNMP allows extensions to be added as a private
  subtree, enabling vendors to create objects to
  manage specific entities.

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CIM v SNMP Info Rep

• CIM can be represented in XML format for use in
  different applications. XSL styles sheets can
  turn the XML based management information into
  MOF syntax.
• SNMP MIBs must conform to SMI (Structure of
  Management Information), which management agent
  understand.