Announcements

Remember to check this regularly!

• Final presentations will be in Tech C211 (IEMS); I'll be there around 10:45AM, please come earlier if you can.
• Remember -- Final presentations of research proposals will be on Friday March 12th at 11am (place to be determined). Each presentation will be of up to 5' long with 2' for questions.
• A minor change of schedule -- We will talk about "Time and Global State" on Wednesday Feb. 3rd and about "Coordination and Agreement" the following Monday (Feb. 15). Tyler will present Clement et al. paper on Byzantine fault tolerant systems on Feb. 17th.
• We will not meet Monday and Wednesday of next week, Feb. 8 and 10; you can use that time to finish your projects!
• Remember we will have a make-up lecture on Friday Jan. 29th at 10AM.
• Please note we will not have class on Monday Jan. 25th; we will discuss RPC Chains on Wednesday.
• The project is out! You can find the handout here.
• Minor change of plans - Zack will present MapReduce on Monday and Mario will talk about ACMS on Wednesday. Make sure you read the right paper!
• A more detailed schedule and a temptative list of papers we will discuss is available here.

Administrative Information

Professor

T.A.

Course Description

Distributed systems are collections of networked computers that coordinate their actions through message exchanges. While their early development followed the emergence of high-speed local area computer networks at the beginning of 1970s, the recent availability of powerful and cheap microprocessors and pervasive connectivity has brought the topic to everyone's attention.
In this course, we will discuss some of the basic principles behind distributed systems and review some of the main paradigms used to organized them.

Location and Time

Mondays and Wednesdays - 3:30-4:50PM, Tech M128.

In compliance with Section 504 of the 1973 Rehabilitation Act and the Americans with Disabilities Act, Northwestern University is committed to providing equal access to all programming. Students with disabilities seeking accommodations are encouraged to contact the office of Services for Students with Disabilities (SSD) at +1 847 467-5530 or ssd@northwestern.edu. SSD is located in the basement of Scott Hall. Additionally, I am available to discuss disability-related needs during office hours or by appointment.

Course Prerequisites

• EECS-343 Operating Systems (or equivalent)
• EECS-340 Introduction to Networking.
• (Please contact me if you do not meet some of these requirements.)

Communication Channels

There will be a number of communication channels set up for this class:

• We will use the course web site (http://www.aqualab.cs.northwestern.edu/classes/EECS345/eecs-345-w10) to post announcements related to the course. You should check this regularly for schedule changes, clarifications and corrections to assignments, and other course-related announcements.
• There will be a newsgroup (cs.345 at news.cs.northwestern.edu) to foster communication outside the classroom.
• There will be an email alias (eecs-345-ta@cs) for the staff that you should use for questions that would be inappropriate to post on the newsgroup/discussion-board.

Materials

Required

• Andrew S. Tanenbaum and Maarten van Steen. Distributed Systems: Principles and Paradigms. Prentice Hall, 2nd Ed., 2006 ("DSP2" from now on).
• John Wilkes, CSP project startup documents, (HPL-CSP-90-42), 11 Oct. 1990 - A great guideline for project proposals.
• A set of research papers I will make available (see the schedule page for a full list).

Very Useful

• Michael J. Hanson, Efficient reading of papers in Science and Technology, 1990 (revised 2000 Dylan McNamee).
• Roy Levin and David D. Redell, An evaluation of the ninth SOSP submissions -or- How (and how not) to write a good systems paper, ACM SIGOPS Operating Systems Review 17(3):35-40 (Jul., 1983)
• George D. Gopen and Judith A. Swan,The Science of Scientific Writing,American Scientist (Nov-Dec 1990), 78: 550-558.

Course Organization

The course is organized as a series of lecture and paper discussions, a small project, a term research proposal and a take home exam.

• Lectures - A set of lectures on the core of the material.
• Readings - Textbook and paper reading in preparation for (not subsitution of) the lecture.
• Project - A small, half-term project that addresses issues, solve problems and exploit techniques from classroom discussions and readings.
• Research proposal - A short research proposal due in the last week of class.
• Exam - A take-home, final given in the last week of class.

Reading Papers

We will be reading one paper per meeting; you should have read the assigned paper before coming to lecture. The paper will be first presented to the group by a student and then discussed in a round-table manner. A student assigned to play devil's advocate will help jumpstart the conversation. To ensure lively discussions, you will be responsible for reading and preparing a short (typed) summary of the assigned paper before each class. Summaries will be due by 11:59PM of the previous day so that the staff has time to read them and bring your comments into next class' discussion.

When reading papers it is normally useful to write down a summary of about a page. Your summary should include at least:

1. Paper title and its author(s).
2. Brief one-line summary.
3. A paragraph of the most important ideas: perhaps a combination of their motivations, observations, interesting parts of the design, or clever parts of their implementation.
4. A paragraph of the largest flaws; maybe an experiment was poorly designed or the main idea had a narrow scope or applicability. Being able to assess weaknesses as well as strengths is an important skill for this course and beyond.
5. A last paragraph where you state the relevance of the ideas today, potential future research suggested by the article, etc.

You may find the following brochure useful: Efficient reading of papers in Science and Technology by Michael J. Hanson, 1990, revised 2000 Dylan McNamee.

Project and Research Proposal

This year we will follow a different model for the project component of the course. During the first half of the quarter you will work, in teams of two, on a small, focused project (e.g. setup and test your own DNS server). The project will help make some of our classrooms discussions a bit more concrete and allow you to gain some practical experience.

For this year project you are asked to develop a functional HTTP/1.0 server. The project will teach you the basics of distributed programming, client/server structures, and some of the many issues in building high performance servers. Each group will be evaluated on the basis of a demo to me. Please see the announcement section of the course web page for instructions on how to sign up for your demos.

Here is the handout for the project: A Simple Web Server - Due date: Feb. 10.

During the second half of the quarter, equipped with a better understanding of the interesting, open questions in the field, you will put together a research proposal (following John Wilkes' CSP guideline). The proposal document will be your only deliverable for this part; what you do with the proposal after the quarter is over is up to you. You could see it as a simply exercise on proposal writing or try pursue it through a EECS 395/495.

Exam

There will be a take-home, final given in the last week of class.

Grading

I use a criterion-referenced method to assign your grade; in other words, your grade will be based on how well you do relative to predetermined performance levels, instead of in comparison with the rest of the class. Thus, if a test has 100 possible points, anyone with a score of 90 or greater will get an A, those with scores of 80 or greater will get a B, those with scores of 70 or greater will get a C, and so on. Notice that this means that if everyone works hard and gets >90, everyone gets an A.

Total scores (between 0 and 100) will be determined, roughly, as follows:

• Summaries of reading assignments 20%
• Class participation 10%
• Project 25%
• Research proposal 25%
• Exam 20%

Topics

• Introduction: Defining distributed systems and their goals, hardware and software concepts, the client-server model and architecture, modern architectures for distributed systems.
• System models: An overview of major systems models; we will use a couple of current papers to make our discussion more concrete.
• Communication: Basics of communication, remote procedure calls, remote object invocation, message-oriented and stream-oriented communication.
• Naming: Naming and locating entities, removing unreferenced entities.
• Timing and global state:Physical, logical time and global state.
• Coordination and agreement:Mutual exclusion, election, consensus and related problems.
• Transaction and concurrency control: Transacions, optimistic concurrency control, distributed deadlocks.
• Availability: Fault tolerant and highly available services.
• Security and Privacy: Secure communication and authorization in distributed systems.