Summary and Review

1
Summary and Review
2
Course Objectives

• The main objectives of the course are to
• introduce different concepts in operating system
  theory and implementation
• identify software design issues for advanced
  computer systems, such as multiprocessors or
  distributed systems
• provide exposure to classic current topics in
  operating system research through reading and
  discussing conference and journal papers
• review and expand on complex concepts from the
  introductory operating systems course, such as
  synchronization, virtual memory, and file systems.

3
Introduce different concepts in OS theory and
implementation

• Microkernel operating systems
• Extensible operating systems
• Virtual machine operating systems

4
Identify software design issues for advanced
computer systems

• Distributed systems architectures
• Distributed system principles/design issues
• Naming
• Replication and consistency
• Fault tolerance
• Distributed systems goals

5
Provide exposure to classic current topics in
OS research in reading and analysis of papers

• Extensible operating systems
• Virtual machine papers
• Racetrack Eraser
• Superpages
• MapReduce Dynamo

6
Review/expand on concepts from the introductory
OS course

• Synchronization
• Shared memory systems
• Distributed systems
• File replication
• Virtual Memory
• Superpages
• File Systems
• Organization/performance
• Distributed file systems
• Caching and replication

7
Unification

• When you review course material try to think
  about connections
• Distributed system architectures as applied to
  systems we studied e.g., compare Google cluster
  architecture to traditional client-server P2P
• Discussion of logical time/Lamport time
  stamps/vector clocks and applications of those
  techniques
• Middleware definition and examples of services
  that could be implemented as middleware.
• Examples what is fault tolerance, how is it
  managed in ltsome system we have studiedgt,
  define transparency and discuss techniques that
  might be used to achieve it,

8
Coverage

• Comprehensive
• Relatively more emphasis on untested material
• Distributed file systems
• MapReduce Dynamo (although we only spent a
  short time on these two systems)
• Memory management/superpages
• Material from previous tests
• Less detail, but remember that much of it shows
  up again and again, so you cant ignore it (e.g.
  architectures, scalability, )
• Mutual exclusion and other forms of
  synchronization are still important

9
New Material

• Distributed file systems
• Basic concepts
• Use of caching
• Cache consistency issues
• Different file semantics
• Replication/replica updates/replica consistency

10
New Material

• Dynamo
• Basic idea
• P2P aspects
• Fault tolerance
• MapReduce
• Basic idea
• Responsibilities of processors
• Fault tolerance issues

11
New Material

• Superpages
• the problem
• Large superpage size versus small
• Use multiple page sizes or just one
• Reservation versus relocation
• Affect of these issues on fragmentation/contiguity

12
Things to Study

• Definitions
• Algorithms (e.g., mutual exclusion, how to place
  an item in a P2P system, )
• Numbered lists 4 reasons for, 3 advantages
  of, main design goals
• Discuss and evaluate
• Anything that can be compared/contrasted e.g.
  RaceTrack v Eraser methodology

13
Test-Taking Tips - 1

• Base length of answer on (1) my suggestion
  brief, 25 words or less, etc. (2) number of
  points its worth, (3) amount of space on test
  paper.
• Dont answer anything I didnt ask about, but DO
  answer the question posed e.g., for the question
  Structurally, how do microkernel operating
  systems differ from traditional

14
Test-Taking Tips - 2

• Dont answer anything I didnt ask about, but DO
  answer the question posed e.g., for the question
  How does a microkernel architecture differ from
  the architecture of a traditional operating
  system?
• DONT talk about advantages/disadvantages dont
  talk about the motivation behind each kind of
  system.
• DO describe the architectures, show where they
  are different.

15
Test-Taking Tips 3

• Budget your time
• If you dont know the answer, come back to it
  later
• Dont waste a lot of time on a 2-point questions
• If you want to add extra details, dont do so
  until youre sure youve covered the basics.

16
Test-Taking tips 4

• Be sure you read the instructions for each
  question before you begin the answer.
• If a question has several parts (a, b, c) dont
  answer part (a) until you have read parts (b) and
  (c) otherwise, you may write things in the
  first part that youll have to repeat later.
• If a question says Answer three out of four,
  dont waste time answering all four.