CS 454
Module 1 - Distributed System
Architectures & Models
System Architecture
Defines the structure of the system components identified functions of each component defined interrelationships and interactions between components defined
CS454/654
1-2
Standardization
Reference Model
A conceptual framework whose purpose is to divide standardization work into manageable pieces and to show at a general level how these pieces are related to one another.
Approaches
Component-based
Components of the system are defined together with the interrelationships between components.
Good for design and implementation of the system.
Function-based
Classes of users are identified together with the functionality that the system will provide for each class.
The objectives of the system are clearly identified. But how do you achieve these objectives?
Example: ISO/OSI Model
CS454/654
1-3
Software Layers
Platform
CS454/654
From Tanenbaum and van Steen, Distributed Systems: Principles and Paradigms
© Prentice-Hall, Inc. 2002
1-4
Layers
Platform
Fundamental communication and resource management services
We won’t be worried about these
Middleware
Provides a service layer that hides the details and heterogeneity of the underlying platform
Provides an “easier” API for the applications and services
Can be as simple as RPC or as complex as OMA
RPC (Remote Procedure Call): simple procedure call across remote machine boundaries OMA (Object Management Architecture) : an object-oriented platform for building distributed applications
Applications
Distributed applications, services
Examples: e-mail, ftp, etc
CS454/654
1-5
Hardware Organization
CS454/654
From Tanenbaum and van Steen, Distributed Systems: Principles and Paradigms
© Prentice-Hall, Inc. 2002
1-6
Software Organization
System
Description
Main Goal
DOS
Tightly-coupled operating system for multiprocessors and homogeneous
Architectures & Models
System Architecture
Defines the structure of the system components identified functions of each component defined interrelationships and interactions between components defined
CS454/654
1-2
Standardization
Reference Model
A conceptual framework whose purpose is to divide standardization work into manageable pieces and to show at a general level how these pieces are related to one another.
Approaches
Component-based
Components of the system are defined together with the interrelationships between components.
Good for design and implementation of the system.
Function-based
Classes of users are identified together with the functionality that the system will provide for each class.
The objectives of the system are clearly identified. But how do you achieve these objectives?
Example: ISO/OSI Model
CS454/654
1-3
Software Layers
Platform
CS454/654
From Tanenbaum and van Steen, Distributed Systems: Principles and Paradigms
© Prentice-Hall, Inc. 2002
1-4
Layers
Platform
Fundamental communication and resource management services
We won’t be worried about these
Middleware
Provides a service layer that hides the details and heterogeneity of the underlying platform
Provides an “easier” API for the applications and services
Can be as simple as RPC or as complex as OMA
RPC (Remote Procedure Call): simple procedure call across remote machine boundaries OMA (Object Management Architecture) : an object-oriented platform for building distributed applications
Applications
Distributed applications, services
Examples: e-mail, ftp, etc
CS454/654
1-5
Hardware Organization
CS454/654
From Tanenbaum and van Steen, Distributed Systems: Principles and Paradigms
© Prentice-Hall, Inc. 2002
1-6
Software Organization
System
Description
Main Goal
DOS
Tightly-coupled operating system for multiprocessors and homogeneous