Download
what is a distributed system n.
Skip this Video
Loading SlideShow in 5 Seconds..
What is a Distributed System? PowerPoint Presentation
Download Presentation
What is a Distributed System?

What is a Distributed System?

102 Vues Download Presentation
Télécharger la présentation

What is a Distributed System?

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. What is a Distributed System? Just insert a network? Mass Storage Computing (CPU) User Interface

  2. Distributed System Services Servers (Storage, Compute) Network User Interfaces Users Users

  3. D.S. Design Issues • Transparency • Flexibility • Reliability • Performance • Scalability

  4. More Design Issues • Global Clocks? • Causality • Information Consistency

  5. Distributed Control • Master/Slave (Issue: Response Time) • Polled • Command -> <-Response • Schedule under control of server • Client/Server (Issue: Server Size) • Interrupt, or Event, Driven • Aperiodic Scheduling • Peer-to-Peer (Issue: Coordination) • No single critical node • Hard to describe or predict

  6. Distributed System:Why or Why not? • Performance • Economics • Reliability • Security

  7. D. S. Architectures • Cooperating Peers • Client-Server • Tiered Client-Server • Data Repository • Compute Servers • Client Stations

  8. “Intranets” • Definition • Using Internet protocols, especially Web tools, for internal MIS • Motivation • Information “push” vs “pull” • Problems • User Capabilities • Corporate Policy or Personal Opinion

  9. Key Protocol Areas • Directory Services • RPCs • Security/Authentication • (Performance) Management • Programming Models

  10. References • ISO RM-ODP • ITU-T X.901/ISO 10746-1/2/3/4 • Amjad Umar Distributed Computing: A Practical Synthesis • PTR Prentice-Hall, Englewood Cliffs, NJ, 1993 • Sape Mullender Distributed Systems, 2d ed. • Addison Wesley, 1993