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NOTE THAT THIS IS NOT THE WIKI FOR THE FALL 2021 EDITION OF THE COURSE, WHICH IS ACCESSIBLE HERE.

CSE 538 (Modeling and Performance Evaluation of Computer Systems)

Course Description

Modern computing systems consist of multiple interconnected components, which all influence performance. The focus of this course is on developing modeling tools aimed at understanding how to design and provision such systems to meet certain performance or efficiency targets, and the trade-offs involved. The course covers Markov chains and their applications to simple queues, and proceeds to explore more complex systems including server farms and how to optimize their performance through scheduling and task assignment policies. The course includes a brief review of the necessary probability and mathematical concepts. Prerequisite: ESE 326.
Note: This is a graduate course, and so while we will go through a brief refresher on probability and transform methods, neither is meant to replace having taken a course on those topics.

Why Should I Take This Course? (or What Should I Expect to Learn from It?)

The course is about creating and solving models that allow you to evaluate the performance of different computer systems (though the techniques are general and applicable to a wide range of other systems).

A model has usually three components: (1) How work arrives to the system, (2) the structure of the system (can jobs wait for service and how many, in which order are they served, etc.), and (3) a characterization of the amount of work each job brings. Performance metrics of interest are commonly in the form of order statistics of quantities such as waiting time, system time (waiting + service), throughput (number of jobs processed per unit of time), loss probability (odds that a job is turned away because of a full system), etc.

The course will equip you with a set of tools for choosing the proper representations for each of those three components, and will show you how to combine and apply them in a number of standard system configurations associated with common computer systems. Through those examples, you will not only learn how to apply those tools, but also how to interpret the results they produce.

Instructor's Background

The bulk of my career has been spent developing and applying algorithmic and performance modeling solutions to problems in computer networking.

I spent about 12 years at IBM Research T.J. Watson developing what at the time were viewed as "next generation" networking solutions. Some of that work led to various quality-of-service enhancement to routers made by IBM, and to the development of what was supposed to be IBM's advanced packet switching network architecture called Networking BroadBand Services (NBBS). That work did not go anywhere as it was caught by the Internet tsunami (to which I also contributed to some extent by co-authoring a few RFCs such as RFC 2212, RFC 2676, RFC 2697, RFC 2698, RFC 2753), but on the modeling front it gave rise to the concept or equivalent or effective bandwidth that predicts how much bandwidth a variable rate connection needs to meet a certain performance level. I left IBM to join the University of Pennsylvania where I continued working on various networking problems, extending into the area of routing, traffic engineering, multimedia applications, etc., anything that had to do with improving performance over packet networks. I also became interested in questions of network economics and technology adoption in systems with positive and negative externalities, and this led to a separate branch of investigations that still continues to this day. Finally, I joined WashU in 2013 where besides continuing investigations related to network economics, I have explored performance questions in cloud systems with a focus on improving efficiency and enabling real-time guarantees, e.g., how to make the cloud useful to systems with tight latency requirements.

For more information see the Background section of my webpage.

Links

• Piazza course page: Please use it for all Q&A related to the class. (Note: You need to sign-up before being able to access the site).
• Canvas Site: Used only for posting grades.

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Announcements

ALL ANNOUNCEMENTS ARE POSTED ON THE PIAZZA COURSE PAGE

Textbook(s)

M. Harchol-Balter, "Performance Modeling and Design of Computer Systems." Cambridge University Press (2013), ISBN: 978-1-107-02750-3

Logistics

• Class times and location: Monday & Wednesday, 4:00pm-5:20pm in TBD.
  • First class is on Monday August 24, 2020, and last class is on Wednesday December 2nd, 2020.
• Class grading: Review problems 5%; Homeworks 25%, Quizzes 20%; Exam 1 25%; Exam2 25%
• Instructor: Roch Guerin, Jolley 304C, email: guerin@wustl.edu
  • Office hours 4 times a week on zoom for 45mins slots):
    • Tuesday 8:00-8:45am & Thursday 8:00-8:45am: zoom info
    • Tuesday 3:00-3:45pm & Thursday 3:00-3:45pm: zoom info
• TAs and office hours: TBD, if any

• Late policy: Homeworks and review problems are expected to be turned in at the start of class on their due date. There will be no exception and no partial credit. On an exceptional basis, if you are unable to make it to class, you can turn in your homework in the CSE department office (Jolley 304). Give your assignment to one of the department staff, and ask them to sign and timestamp it. The timestamp must precede the start time of the class.

• Asking questions: You can obviously ask face-to-face questions during any of the office hours, but the other and possibly better means to get your questions answered is to use the Piazza site setup for the course (you will need to register to be able to access it). The TA (if any) and I will monitor the site and do our best to answer questions in a timely manner. Posting questions on Piazza has the advantage that questions and answers are available to all students, and it is often the case that if you have a question, other students have a similar one. Because of that, neither the TA nor I will respond to email questions. So please use the Piazza site as much as you can and don't hesitate to ask as many questions as you need to; there is no such thing as a dumb question.

• Exam 1^*: Monday October 19, 2020, in class.
• Exam 2^*: Wednesday December 11, 2020, 7:20-8:00pm in TBD.
• ACADEMIC INTEGRITY: Please make sure you are familiar with Washington University Academic Integrity Policy, as it will be strictly applied.

^* EXCEPT FOR PROPERLY DOCUMENTED MEDICAL OR FAMILY EMERGENCY REASONS, THERE WILL BE NO MAKE-UP TIMES FOR EXAMS OR QUIZZES. YOU NEED TO ARRANGE OTHER ACTIVITIES SO AS TO AVOID CONFLICTS.

University Policies & Resources on Sexual Assault, Bias, and Mental Health

Accommodating Special Requirements

Washington University is committed to providing accommodations and/or services to students with documented disabilities. Students who are seeking support for a disability or a suspected disability should contact Disability Resources at 935-4153. Disability Resources is responsible for approving all disability-related accommodations for WU students, and students are responsible for providing faculty members with formal documentation of their approved accommodations at least two weeks prior to using those accommodations. I will accept Disability Resources VISA forms by email and personal delivery. If you have already been approved for accommodations, please provide me with a copy of your VISA within the first two weeks of the semester.

Accommodations based upon sexual assault

The University is committed to offering reasonable academic accommodations to students who are victims of sexual assault. Students are eligible for accommodation regardless of whether they seek criminal or disciplinary action. Depending on the specific nature of the allegation, such measures may include but are not limited to: implementation of a no-contact order, course/classroom assignment changes, and other academic support services and accommodations. If you need to request such accommodations, please direct your request to Kim Webb (kim_webb@wustl.edu), Director of the Relationship and Sexual Violence Prevention Center. Ms. Webb is a confidential resource; however, requests for accommodations will be shared with the appropriate University administration and faculty. The University will maintain as confidential any accommodations or protective measures provided to an individual student so long as it does not impair the ability to provide such measures.

If a student comes to me to discuss or disclose an instance of sexual assault, sex discrimination, sexual harassment, dating violence, domestic violence or stalking, or if I otherwise observe or become aware of such an allegation, I will keep the information as private as I can, but as a faculty member of Washington University, I am required to immediately report it to my Dean or directly to Ms. Jessica Kennedy, the University’s Title IX Director. If you would like to speak with directly Ms. Kennedy directly, she can be reached at (314) 935-3118, jwkennedy@wustl.edu, or by visiting the Title IX office in Umrath Hall. Additionally, you can report incidents or complaints to the Office of Student Conduct and Community Standards or by contacting WUPD at (314) 935-5555 or your local law enforcement agency. See: Title IX.

You can also speak confidentially and learn more about available resources at the Relationship and Sexual Violence Prevention Center by calling (314) 935-8761 or visiting the 4th floor of Seigle Hall. See: RSVP Center.

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