Lecture for Chapter 2.8 (Fall 11)

Distributed System Concepts
and Architectures
Srujana Gorge
Introduction Of Distributed System
Communication Network Models
Major Design Issues
Distributed Computing Environment(DCE)
Latest Work
Future Work
What is Distribution system?
• A distributed system is a collection of autonomous
computers linked by a computer network that appears
to the user as a single computer
Why distributed system?
Resource sharing
Computation speedup
In event of system resource failure, shift its
processing load to another similar resource
• Multiple computer systems collaborating to
deliver a single application
• Multiple applications collaborating together as a
Disadvantages of Distributed Systems
• Difficulties of developing distributed software
• Networking Problems
• Security problems
Design Goals
Why Operating System Services?
• OS provides an environment for the executions
of the programs.
• Services are provided for the convenience of the
programmer , to make the programming task
• Services provided differ from one operating
system to another operating system.
Program Execution
I/O Operations
File-system manipulation
Error Detection
Resource Allocation
Communication Network Protocols
• For a network architecture, rules and standards must be set up to
govern the communication. Communication Protocols are sets of
rules that regulate the exchange of messages to reliable and orderly
flow of information.
• Two most popular network protocol suites:
OSI (Open Systems Interconnection) from ISO (International
standards organization)
TCP/IP(Transmission Control Protocol/Internet Protocol) from
the DoD (U..S Department of Defense)
Design Issues of Distributed Systems
Reliability and fault tolerance
Achieving Transparency[A. S. Tanenbaum]
Distributed Computing Environment
• DCE provides a complete Distributed Computing Environment
• It provides security services to protect and control access to data,
name services that make it easy to find distributed resources, and a
highly scalable model for organizing widely scattered users,
services, and data.
• DCE runs on all major computing platforms and is designed to
support distributed applications in heterogeneous hardware and
software environments. DCE is a key technology in three of today's
most important areas of computing: security, the World Wide Web,
and distributed objects.
Latest Work: Asian computers join forces
against Avian Flu
• Computers can simulate a large number of chemical compounds and
measure their ability to fit snugly into the chemical coating of a
virus, thereby blocking its ability to function properly
• “Avian Flu DC2 Refinement” is the latest attack on Avian Flu using
Grid Computing
• The grid technology allowed 125 processor cores — the heart of every
computer — to join forces even though they were thousands of miles apart,
All the computing jobs were completed within four weeks. A total of
1,111 CPU-days were used, which is equivalent to running a single
computer for over three years. Over 160,000 files generated a large volume
of data, about 12.8 gigabytes, which was collated in a database.
Now the community is hardly working to find drugs for virus behind
dengue fever.
Reference Link: http://www.isgtw.org/feature/feature-asiancomputers-join-forces-against-avian-flu
Future Work:A distributed intrusion detection
system for wireless ad hoc networks
• In multi-hop mobile ad hoc network (MANET), mobile nodes
communicate with each other forming a cooperative
radio network.
• Security remains a major challenge for these networks due to
their features of open medium, dynamically changing
topologies, reliance on cooperative algorithm.
• Most of the currently existing intrusion detection algorithms
designed for these networks are insecure, inefficient, and have high
rates of false positives.
• So, In order to provide the security to manet, a new approach has
been proposing to bring out the complementary relationship
between key distribution and intrusion detection for developing an
intrusion detection protocol for ad hoc networks, which will work
even in the failure of nodes.
A distributed intrusion detection system for
wireless ad hoc networks
• Distributed Operating Systems & Algorithms, Randy Chow and
Theodore Johnson, Addison Wesley, 1997.
• Distributed Systems principles and paradigms by Andrew S.
Tanenbaum, Maarten van Steen, 2002.
• Ge, Z.; Figueiredo, D.R.; Sharad Jaiswal; Kurose, J.; Towsley, D.;
Modeling peer-peer file sharing systems, INFOCOM 2003. TwentySecond Annual Joint Conference of the IEEE Computer and
Communications Societies. IEEE Volume 3, 30 March-3 April 2003
Page(s):2188 - 2198 vol.3
Thank You!
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