CS 5523 Operating Systems
Final Examination Review
Spring 2002

The following outline is provided as a study guide. You should also review the end-of-chapter questions. Do not expect either the questions asked here or the end-of-chapter questions to be on the exam in the same form. Rather, I will try to come up with questions that test your understanding of these concepts.

• System models and fundamental models (Chapter 2)
  • System architectures:
  • Client-server
  • Proxy, tunnel, gateway
  • Code execution models such as applets and servlets
  • Object-oriented services
  • Peer-to-peer
  • What is the difference between a fundamental model and an architectural model?
  • Synchronous versus asynchronous communication and how this affects interaction.
  • Event ordering and types of events for different types of communication channels.
  • Different types of failure models and how they impact program behavior.

• Networks and communication (Chapters 3 and 4)
• How do the characteristics of networks (performance, scalability, reliability, security, mobility, quality of service) affect the OS and applications?
• Given a topology and information about latency, transfer rate, and message sizes, you should be able to estimate the time it takes to process requests across a network.
• Understand connection-oriented and connectionless protocols. How are connections actually achieved on current networks?
• Understand how TCP and UDP work.
• Know the steps involved in establishing and using communication in using TCP and UDP (you don't need to know details of parameters for system calls, but rather what needs to be done).
• Understand the difference between TCP, UDP and IP.
• Understand how packets are routed on the internet (not detailed routing algorithms).
• Have a basic understanding of how firewalls work.
• Interprocess communication in Java and Unix.
• Be able to draw a state diagram for a communication protocol.
• Be able to draw a timing chart for message exchanges in a protocol (time lines for the participants that are interconnected).
• No OSI layers, IP routing algorithms, mobileIP, IPv6, Ethernet (beyond a basic understand of the ideas), ATM.
• Communication above the network layer (Chapters 4 and 5)
• The object model and distributed objects?
• What is middleware and what is it good for?
• What is remote invocation?
• What is an RPC?
• What is marshalling, why is it needed and how is it accomplished?
• How do remote references work?
• What is serialization? Reflection?
• Different models of client-server communication (request, request-reply, request-reply-acknowledge).
• Where these models might be used
• What kind of behavior is expected when R, RR or RRA are used over TCP? over UDP?
• How are timeouts, history and message sequencing used in the implementation of these client-server communication protocols?
• HTTP
• Java RMI
• No group communication or Sun RPC details.
• Operating System Support (Chapter 6)
• OS architectures - monolithic versus kernel.
What they are? What operating systems have these architectures? How is basic resource management and OS operation accomplished in systems using these architectures? OS basics - How does an OS run a program? What is the layout of a process in a typical OS? How is protection achieved? What is involved in process creation? What is a process execution environment?
• Thread architectures - user-level, kernel-level and hybrid?
• What resources are per-process? Per-thread?
• How does thread execution work for user-level threads? For kernel-level threads?
• Tradeoffs between using multiple threads and multiple processes for implementing servers.
• Thread organizations - thread-per-request, worker-pool, thread-per-object.
• Invocation performance.
• Asynchronous operation of invocation mechanisms.
• Security (Chapter 7)
• Types of attacks.
• Overview of encryption (public keys, shared keys, authentication, digital signatures, certificates).
• Kerberos and Needham-Shroeder.
• Secure sockets.
• No details of crypto algorithms, Millicent, or X509 details.
• Distributed File Systems (Chapter 8)
• Distributed file system requirements.
• NFS architecture.
• Andrew architecture.
• Farsite.
• Comparison of different systems --- how are they similar, how are they different?
• Name Services (Chapter 9)
• Name service requirements.
• Name spaces.
• Methods for name resolution and navigation.
• Caching issues in name services.
• Naming contexts.
• Basics of directory and discovery services.
• No X.500 or GNS details.

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Last revision: May 6, 2002 at 4:10 pm