Management Architectures CORBA as a Management Architecture

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Management Architectures CORBA as a Management
Architecture
II
Part
2
CORBA as a Management Architecture
Chapter 7
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Learning Objectives

• Object Management Architecture
• Object Model and Interface Definition Language
• Object Request Brokers and Inter-ORB Protocols
• Organizational Model
• CORBAservices
• CORBAfacilities and Systems Management Facilities
• Domain Interfaces
• Extension of CORBA
• Chapter Summary

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Object Management Architecture

• CORBA Common Object Request Broker Architecture
• It is an important architecture for management
  applications
• Products used in the management of end systems
  and applications are or will be based on OMG
  (Object Management Group) technology.
• OMG aim is to have one single architecture for
  the development, use, and management of
  distributed systems
• There is no longer a fundamental difference
  between management applications and other
  applications in development
• Ability to model both user and management data
  using the same tools
• Eliminating the special management development
  tools and improving efficiency and
  cost-effectiveness to the development process
• Transmitting user and management data of an
  application via the same mechanism
• Therefore, acquiring on communication system to
  install and maintain.

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Object Management Architecture

• CORBA Common Object Request Broker Architecture
• OMA for distributed object, first published in
  1992 provides a framework that allows a
  location-transparent cooperation of objects in
  heterogeneous environment
• OMG is an industrial consortium with more than
  800 members that was founded by 8 companies in
  1989
• It is organized into task forces for
  standardization of areas
• It publishes or sent out a request-for
  information (to be examine)
• It formulates a request for proposal
• Member companies responds with a letter of intent
• COBRA
• (ORB) an infrastructure component that mediates
  interaction between client applications that
  request services and the server applications that
  provide these services.

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Object Management Architecture

• CORBA
• It establishes the client-server relationships
  between objects
• ORB is often refer to as Object Bus. Because it
  receives a request and locate the server object,
  transfer the parameters, invoke the methods, and
  deliver the results.
• CORBA components standard defines the OMA
  Communication Model
• CORBA specifies a fundamental object model and
  with the interface definition language, the
  syntax for describing the object interfaces
• It also defines the OMA Information Model
• Its interoperability architecture, a
  subarchitecture refines the OMA Organizational
  Model (cooperation of equal objects)
• Categories of Object Interfaces
• Four categories of Object Interfaces
• Common object Services specification
• Forms the heart of the OMA functional model.
• It supply the basic functionality needed to
  enable a system and the objects to be used
  effectively in a distributed environment
• Different types of services are available for
  instantiating, naming, storage for objects.
• 15 object services have been specified with
  standard

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Object Management Architecture

• Categories of Object Interfaces
• Four categories of Object Interfaces
• Common facilities architecture (COBRAfacilities)
• Provides universally applicable services for all
  applications
• It identifies the following areas as those from
  which these services originates for the first
  phase of the definition process User interface,
  information management, system management, and
  task management.
• Domain interfaces
• Services of the highest layer below the actual
  applications themselves
• Used in special areas of application domains such
  as heath care and financial world. Referred to as
  Business Objects
• Application objects
• The object that execute the actual application
  (CASE tool)

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Object Model and Interface Definition Language

• OMI Definition Language
• OMG information model is based on an
  object-oriented approach
• Its architecture is not specifically oriented
  towards network and system management but in
  principle support all distributed applications
• Unlike OSI or Internet management, it does not
  define managed objects, but instead the
  fundamental properties of very general objects
• OMA core object model mainly provides design
  portability for distributed applications, serves
  as the basis for the information or object model
• The core model combined with one or more
  components is called a profile.
• Object Model
• Objects within OMA are general

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Object Model and Interface Definition Language

• Object Model
• Objects within OMA are general
• Object implementation representing the program
  code that implements the operations that can be
  carried out on the object
• Object reference represent the identity of an
  object
• Operation an interaction provide by an object
• Signature of an operation consists of
• An identifier (the name) of the operation
• The result type
• A possibly empty list of parameters

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Object Model and Interface Definition Language

• Interface Definition Language (IDL)
• IDL based on C, and contains the following
• Constant and data type declarations includes
  signed or unsigned integers either 16 or 32 bits
  in length
• IEEE single-precision or double precision
  floating-point numbers
• Characters, variable-length strings, Boolean
  values.
• Operations declared in a similar way to C
• Declaration contains the name of the operation
• A result type (void in case no result is
  expected)
• A possible list of parameters
• Attributes declarations of attributes help to
  simplify the interface definition
• The represent one pair of operations for reading
  and setting certain type of value
• Are short form for a pair of access operation
• Interface declarations declaration of group
  constants, data type, attribute, and operation
  declaration into single interface per object
• Module declaration can contain any correct IDL
  declarations as well as other module
  declarations. Defines scopes for names.

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Object Model and Interface Definition Language

• Mapping IDL to Implementation Language
• Mapping DLL to languages is needed to enable
  objects to cooperate in a heterogeneous
  environment
• Mapping are currently available for the following
  languages C, C, Smalltalk, Ada, COBOL, and
  Java
• Object Request Brokers and the Inter-ORB
  Protocols (3)
• Clarification needed on client side on how
  operations of remote objects with a known IDL
  description can be used locally. Interface known
  as ORB API
• On the server side operations of an interface
  defined using IDL are implemented in a
  programming language
• Client and server on separate system or supplied
  by separate vendors a protocol is needed for
  cooperation of independent ORBs in heterogeneous
  environment

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Object Request Brokers and the Inter-ORB
Protocols (3)

• The Client Side CORBA (interactions between the
  client objects and the ORB
• Client IDL stubs - provide the static
  infrastructure to objects and services they offer
  (methods and parameters are specified at the time
  of translation)
• Dynamic innovation interface (DII) methods and
  parameters that are to be invoked do not have to
  determined until the runtime
• Interface repository contains interface
  signatures for the registered objects in IDL
  notation, called metadata it can be stored and
  accessed
• ORB interface supply functions that are
  generally useful for applications, such as
  conversion of object references into strings and
  the reverse, access to metadata.
• The Server Side of CORBA
• When an ORB receives an operation request from a
  client, it must select the appropriate server
  object and invoke the operation using the
  parameters supplied by the client.

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Object Request Brokers and the Inter-ORB
Protocols (3)

• The Server Side of CORBA
• 4 components
• Static skeletons or server IDL stubs provide
  static interface to the services offered by an
  object
• Dynamic skeleton interface enables method
  invocations for which no static request
  description is provided to be processed during
  runtime. It interprets incoming messages while
  establishing the respective target object and the
  method invoked at the same time
• Object adapter forwards method invocations from
  client to the server object, providing link
  between the ORB and the connected skeletons

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Object Request Brokers and the Inter-ORB
Protocols (3)

• The Server Side of CORBA
• 4 components
• Inmplementation repository stores information
  about the object classes implemented by the
  server
• Inter-ORB Protocols (to enable communication
  between ORBs by different vendors)
• 3 Protocols are required
• General inter-ORB protocol (GIOP) specifies the
  syntax and the semantics of the messages
  exchanged between ORBs. This defines seven (7)
  PDUs
• Invocation of a method, Return of results,
  Termination of request, Queries to test validity
  of object references, Termination of connections,
  and Error notifications.
• GIOP is to connect with any connection-oriented
  transport protocol
• GIOP also defines interoperable object reference

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Object Request Brokers and the Inter-ORB
Protocols (3)

• Inter-ORB Protocols (to enable communication
  between ORBs by different vendors)
• 3 Protocols are required
• Internet inter-ORB protocol (IIOP) defines the
  mapping of GIOP to TCP.
• How GIOP PDUs should be framed into TCP PDUs.
• Environment-specific inter-ORB protocol (ESIOPs)
  are designed for communication over the
  protocols or protocol stacks
• Example Products and Solutions
• Tivoli Management Architectures
• HP Open View Distributed Management
• Investigate each of these.
• Organization Model

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CORBAservices

• Object Services in COBRA are a collection of
  system services assembled in the form of IDL
  interfaces
• COBRA services are not management specific
• The Even Service
• Supports the communication of objects using
  asynchronous message that have not be directly
  requested
• The object have two roles
• Suppliers that generate and transmit event
  messages
• Consumers that receive and process the messages
• The event service Push and Pull communication
• Push model supplier notifies the consumer
• Pull model consumer initiate service
• Generic and Typed communication

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CORBAservices

• The Even Service
• Generic and Typed communication
• Generic communication
• Push and Pull operations only have one type all
  data is encapsulated into the message
• Typed communication
• Events are transmitted through the invocation of
  operations that have an application-specific
  IDL definition

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CORBAservices

• Other Services
• Naming services (allows for name relative to a
  name context )
• Persistent object service (supplies standard
  interface)
• Life cycle service (allow for creation, deletion,
  copying)
• Concurrency control service
• Externalization service
• Relationship service
• Transaction service
• Query service
• Licensing service
• Property service
• Time service
• Security service
• Trading object service
• Object collection service

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CORBAfacilities and Systems Management Facilities

• 4 areas of service
• User interface for document processing
  (printing and displaying of objects
• Information management support information
  modeling, storage, processing and exchange
• Task management supplies functions for
  automating and coordinating workflows
• System management administration of complex
  data processing systems
• The Managed Set Service
• Allows for set of related objects to be assembled
  and administered for management purposes
• Two (2) services are Interface set and Interface
  member
• The Instance Management Service
• It supports lifecycle management, the creation
  and deletion of managed objects
• Three (3) services
• Managed Instance,
• Instance Manager,
• Library Object

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CORBAfacilities and Systems Management Facilities

• The Policy Management Service
• Domain Interfaces
• The Notification Service
• The Topology Service
• The Log Service
• Extension of COBRA
• Distributed Component Support
• CORBA component model
• CORBA scripting language
• Support for Object by Value
• Multiple Interfaces
• Java and Internet integration and legacy support
• Java language to IDL
• Firewall specification

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Next
DMTF (Desktop Management Interface
Chapter 8