IntroductionCS-4513 D-term 20081 Introduction CS-4513 Distributed Computing Systems (Slides include materials from Operating System Concepts, 7 th ed.,

IntroductionCS-4513 D-term 2008 1

Introduction

CS-4513Distributed Computing Systems

(Slides include materials from Operating System Concepts, 7th ed., by Silbershatz, Galvin, & Gagne, Distributed Systems: Principles & Paradigms, 2nd ed. By Tanenbaum and Van Steen, and

Modern Operating Systems, 2nd ed., by Tanenbaum)


Outline for Today

• Introduction to CS-4513

• What is “Distributed Computing”– An example of a distributed computation

• Remote Procedure Call

• Assignment of Project #1


CS-4513, Distributed Systems

• Continuation of CS-3013, Operating Systems– File Systems

• No coverage in A- or C-Term CS-3013 (2007-2008)

• Distributed System Topics– Remote Procedure Call

– Naming

– Security and Encryption

– Atomic Transactions

– …


Four Principal Abstractions Implementedby almost all Operating Systems

• Processes and Threads• Abstracts notion of “processor”

• Concurrency and synchronization

• Virtual Memory• Address space in which a process “thinks”

• Physical memory is cache of virtual memory

• Files• Named, persistent storage of information

• Sockets and connections• Conversations among processes/threads across a network


Four Principal Abstractions Implementedby almost all Operating Systems

• Processes and Threads• Abstracts notion of “processor”

• Concurrency and synchronization

• Virtual Memory• Address space in which a process “thinks”

• Physical memory is cache of virtual memory

• Files• Named, persistent storage of information

• Sockets and connections• Conversations among processes/threads across a network

OS course

OS course

This course

CS-4514


CS-4513, Distributed Systems

• Continuation of CS-3013, Operating Systems– File Systems

• No coverage in A- or C-Term CS-3013 (2007-2008)

• Distributed System Topics– Remote Procedure Call

– Naming

– Security and Encryption

– Atomic Transactions

– …


Textbook and Web

• Textbook:–– Distributed Systems: Principles and Paradigms,

Tanenbaum and Van Steen, Prentice-Hall, 2007

• Supplemental:– You should own or have access to one of the following from CS-3013– Operating Systems Concepts, 7th ed, by Silberschatz,

Galvin, and Gagne, John Wiley and Sons, 2005– Modern Operating Systems, 2nd edition, by Andrew S.

Tanenbaum, Prentice Hall, 2001

• Course Information:– http://www.cs.wpi.edu/~cs4513/d08/

http://www.cs.wpi.edu/~cs4513/d08/


Prerequisites

• Prerequisites:–– CS-3013, Operating Systems, or equivalent– C and C++ programming, esp. “low level”

programming– Data structures

• pointers, linked lists, malloc(), free()

– Unix/Linux user experience and access


Co-Requisite

• CS-4514, Computer Networks

or• CS-502, Operating Systems (graduate level)

or

• Tutorial by R. Skowyra• Sockets

• Connections

• OSI 7-layer model


Schedule & Logistics

• Schedule– Goddard Hall 227– 8:00 – 9:50 AM – Tuesdays & Fridays thru April 29– No class on April 15– 14 classes total

• Exams– Mid-term on ~April 1– Final on April 29

• Unannounced Quizzes– May occur at any time– May be at beginning, middle, or

end of class

• Mobile Phones, pagers, laptops, and other devices OFF during class

• Two Programming Projects– Fossil Lab– One individual, one team

• Office Hours– Adjunct Office, Fuller 239– by appointment, or– Normally ½ hour after class

• Teaching Assistant– Rick Skowyra– Isaac Chanin

• Contacts– <Professor’s last name> @ cs.wpi.edu– Adjunct office phone:

(508) 831-6470 (shared, no messages)– cs4513-staff at same domain


Grading

• Grading– Exams – 40%

– Programming Projects – 40%

– Class participation, homework, & quizzes – 20%

• Unless otherwise noted, assignments are to be completed individually, not groups

• Late Policy – 10%/day– But contact Professor for extenuating circumstances at

least one day prior to deadline or exam date

• WPI Academic Honesty policy


Miscellaneous

• Is this course the capstone for a Minor in CS?

• Anyone needing a project for BS & MS credit?

• How many students feel they need tutorial on networking

• Scheduling options


Project Work

• Two project• One individual – Remote Procedure Call

• One team – Choice of Distributed or File System topics

• Fossil Lab• Newly refurbished

• Your accounts

• Virtual machines


Cloning a Virtual Machine

• Log in using Fossil password• Navigate to P drive

• Open Clonable-SUSE-Linux-10.3

• Double-click on VMware configuration file

• Select “Clone this virtual machine”

• Root and “student” password• Fossil-B17

• Linked vs. Full clone• Linked – about 2-3 gigabytes, tied back to master

• Full – 8-9 gigabytes, can stand alone– Exceeds your quota on Fossil server


Questions?


Ground Rule

• There are no “stupid” questions.

• It is a waste of your time and the class’s time to proceed when you don’t understand the basic terms.

• If you don’t understand it, someone else probably doesn’t, either.


Instructor — Hugh C. LauerAdjunct Professor

• Ph. D. Carnegie-Mellon 1972-73– Dissertation “Correctness in Operating Systems”

• Lecturer: University of Newcastle upon Tyne, UK• Approximately 30 years in industry in USA• Research topics

– Operating Systems– Proofs of Correctness– Computer Architecture– Networks and Distributed Computing– Real-time networking– 3D Volume Rendering– Surgical Simulation and Navigation– …


Systems Experience

• IBM Corporation• University of Newcastle• Systems Development Corporation• Xerox Corporation (Palo Alto)• Software Arts, Inc.• Apollo Computer• Eastman Kodak Company• Mitsubishi Electric Research Labs (MERL)• Real-Time Visualization

• Founded and spun out from MERL• Acquired by TeraRecon, Inc.

• SensAble Technologies, Inc.• Dimensions Imaging, Inc. (new start-up)


VolumePro™

• Interactive volume rendering of 3D data such as• MRI scans

• CT scans

• Seismic scans

• Two generations of ASICs, boards, software• VolumePro 500 – 1999

• VolumePro 1000 – 2001

• CTO, Chief Architect of VolumePro 1000• 7.5-million gate, high-performance ASIC

• 109 Phong-illuminated samples per second


Sample images from VolumePro


Operating Systems I have known

• IBSYS (IBM 7090)

• OS/360 (IBM 360)

• TSS/360 (360 mod 67)

• Michigan Terminal System (MTS)

• CP/CMS & VM 370

• MULTICS (GE 645)

• Alto (Xerox PARC)

• Pilot (Xerox STAR)

• CP/M

• MACH

• Apollo DOMAIN

• Unix (System V & BSD)

• Apple Mac (v.1 – v.9)

• MS-DOS

• Windows NT, 2000, XP

• various embedded systems

• Linux

• …


Other

• Two seminal contributions to computer science

• Duality hypothesis for operating system structures (with Roger Needham)

• First realization of opaque types in type-safe programming languages (with Ed Satterthwaite)

• 21 US patents issued• Computer architecture• Software reliability• Networks• Computer graphics & volume rendering


Class Discussion(laptops closed, please)

What is Distributed Computing?


Distributed System

• Collection of computers that are connected together and (sometimes) interact

• Many independent problems at same time• Similar• Different

• Or …– One very big problem (or a small number)

• Computations that are physically separated• Client-server• Inherently dispersed computations


Distributed Computing Spectrum

• Many independent computations at same time• Similar — e.g., banking & credit card; airline reservations

• Different — e.g., university computer center; your own PC

• Or …– One very big problem (or a few)

• Computations that are physically separated• Client-server

• Inherently dispersed computations


Multiprocessing Distributed Computing(a spectrum)

• Many independent problems at same time• Similar — e.g., banking & credit card; airline reservations


• Or …– One very big problem (too big for one computer)

• Weather modeling, Finite element analysis; Drug discovery; Gene modeling; Weapons simulation; etc.


• Inherently dispersed computations


Multiprocessing Distributed Computing(a spectrum)

• Many independent problems at same time• Similar — e.g., banking & credit card; airline reservations


• Or…– One very big problem (too big for one computer)

• Weather modeling, Finite element analysis; Drug discovery; Gene modeling; Weapons simulation; etc.


• Dispersed – routing tables for internet; electric power distribution.


Observation

• Same spectrum applies to multiprocessor systems– Much more tightly coupled that traditional “distributed

systems”

• Some differences– “Multiprocessor systems”

• Usually under same management, often in same room

• Very fast communication

– “Distributed systems”• Sometimes not under same management

• Slower communication


Another Observation(attributed to R. Hamming)

• When you change the operating point of a system by an order of magnitude …

… you introduce qualitative changes in how to approach problems


Observation

• Same spectrum applies to multiprocessor systems– Much more tightly coupled that traditional “distributed

systems”

• Some differences– “Multiprocessor systems”

• Usually under same management

• Very fast communication

– “Distributed systems”• Sometimes not under same management

• Slower communication

So there is a qualitative

difference in how we

approach these two

kinds of systems


Let’s look at an example

• An inherently distributed computation– I.e., parts of the computation must occur at

physically separate locations– Under separate administrations

• Internet routing tables


The Internet

• A vast collection of independent computers– ~ 600 106

• All connected together• Any computer can send a message to any

other• Messages broken up into little packets

• Question: how do packets find their way to destinations?


Internet


Distributed routing algorithm(simplified example)

• Each node “knows” which networks are directly connected to it.

• Each node maintains table of distant networks• [network #, 1st hop, “distance”]

• Adjacent nodes periodically exchange tables• Update algorithm (for each network in table)

• If (my distance to network > neighbor’s distance to network + my distance to neighbor), then …

• … update my table entry for that network so that neighbor is first hop.


Distributed routing algorithm(result)

• All nodes in Internet maintain reasonably up-to-date routing tables

• Rapid responses to changes in network topology, congestion, failures, etc.

• Very reliable with no central management!


Characteristic

• The routing algorithm is inherently distributed

• Different parts execute in physically separated locations

• Only nearby nodes “know” whether – Neighbors are up or down– Networks are congested or not


Big networks

• Network management systems• Monitoring health of network (e.g., routing tables)

• Identifying actual or incipient problems

• Data and statistics for planning purposes


Next Topic

Questions?

IntroductionCS-4513 D-term 20081 Introduction CS-4513 Distributed Computing Systems (Slides include materials from Operating System Concepts, 7 th ed.,

Documents

operating systems file

cterm cs

modern operating systems

operating systems processes

operating systems concepts

tanenbaum slide

introduction cs

network slide