CSE538 Wiki:Course overview & logistics

CSE 538: Modeling and Performance Evaluation of Computer Systems - FALL 2024

COURSE WELCOME

Welcome to CSE 538T. My name is Roch Guerin (pronouns: he/him/his) and I am the instructor for the class. As part of this course, we will be meeting in person on Monday and Wednesday 4:00-5:20pm. In addition to lectures that will allow direct interactions, office hours (either in-person or over zoom) and the class' Piazza site will give us plenty of opportunities to interact. In particular, the Piazza site will be the main vehicle to post announcements and answer questions you may have outside lectures or office hours. Questions sent over email will be redirected to Piazza with a request to post them there. Students get added to the Piazza course site on a rolling basis as they enroll in the class, but if you have not, you can sign-up directly using this link.

In case if you absolutely need to reach me personally, my email is guerin@wustl.edu. You can also find a bit more about myself either on my webpage or in the Instructor Background below.

Zoom & Video Access

Access to the lectures over zoom will normally not be available, but may be offered to accommodate special circumstances, e.g., extended illness. Zoom access will require early notification and is at the discretion of the instructor. When offered, it will be made available through Canvas. Note that remote participation will not allow the same level of interactions as if attending in-person.

On the other hand, to provide students with the ability to review the material covered in lectures, video recordings are also available on the course Canvas site under the "Pages" tab on the course main page. Two types of videos are available, pre-recorded and "live" (from the fall 2020 lectures). They differ in their format, with pre-recorded versions often a bit shorter as live recordings include lecture material, Q&As, and brief reviews of practice and/or preview problems for that lecture.

Getting Started

Coming back to the course, note the "T" suffix of the course, which is meant to indicate that this is a Theory course. Hopefully, this is not a surprise (in its first year, the course had an "S" suffix and the students were then justifiably surprised. Not so anymore!), as theory is very much the course's focus even if it also has some very practical applications. The instructions below are meant to facilitate you getting started in the class, and so please read them carefully.

• First and foremost, make sure you bookmark somewhere the URL for the course wiki: https://classes.engineering.wustl.edu/cse538-online
  • The wiki sidebar shows you the different sections of the course wiki. Some are devoted to the course structure and approach, while others are meant to give you quick access to most of the material used in the course, e.g., lecture slides, problems we will use to practice material from the slides, assignments, etc.
  • The course “Syllabus & (tentative) schedule” offers a birds-eye view of the course, its content, what will be covered in what order, and due dates for assignments and quizzes, together with links to the corresponding material.
  • Office hours have been scheduled 4 times a week in 45mins slots. The schedule is here. They can be used to either go over problems to put the material in practice, or to answer specific student questions.
• Go over the rest of this page and the Course structure section and make sure you familiarize yourself with their content, including noting the due dates for the different types of assignments, and carefully reading the course’s Academic Integrity Policy. The latter includes policies for collaboration as well as restrictions on posting solution material made available through Canvas to students enrolled in the course.
• If you have not already been added to the course Piazza site (I enrolled all the students showing up as registered), please make sure you sign-up using the Piazza sign-up page. We will use Piazza for all Q&As
• Familiarize yourself with the course Canvas site as all grades will be posted there and, as mentioned, access to course videos is provided there as well.
• Understand the purpose of the Preview problems and Reading Assignments
• Secure a copy of our textbook as the majority of the lectures follow it closely and most of the problems we will be working on come from there.
• And finally take a look at your first preview problems. Unlike subsequent Preview problems, they do not need to be turned in, but the two problems included will give you a sense of what to expect.

Course Description & Prerequisites

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.

Prerequisites: A solid background in probability is required. A course such as ESE 326, Probability and Statistics for Engineering, or equivalent is probably adequate, but having taken a more advanced course such as ESE 520, Probability and Stochastic Processes, can be helpful, if only because you will have had more practice with some of the concepts. Note that while we will go through a very brief refresher on probability and transform methods at the beginning of the course, this is not meant to replace having taken a course covering 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, a.k.a, the arrival process, (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, a.k.a., its service or processing time. 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 of equivalent or effective bandwidth that predicts how much bandwidth a variable rate connection needs to meet a certain performance level. I eventually 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 to Other Sites (including Announcements)

• Piazza course page: Please use it for all Q&A related to the class.
  • In particular, ALL ANNOUNCEMENTS WILL BE POSTED ON THE PIAZZA COURSE PAGE

(Note: If you were registered for the course at the start of the semester, you should have been added to the course's Piazza site, but otherwise you will need to sign-up to be able to access it).

• Canvas Site: Used mostly for posting grades and any material with access limited to students enrolled in the course, e.g., some practice problems as well as all the videos of lectures and preview problems available here.

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 Jubel Hall 121 (zoom-based participation is not available by default, but may be offered to accommodate exceptional circumstances, e.g., extended illness, provided it is requested ahead of time. Note though that it may not offer the same ability to ask questions in real-time. When offered, zoom access will be provided through the course Canvas site here).
  • First class is on Monday August 26, 2024, and last class is on Wednesday December 4, 2024.
• Class grading: Grading will be based on three components: Review problems, Homeworks, and Quizzes (see Overview & Grading for details and relative weights) - There are no midterm or final exams.
• Instructor: Roch Guerin, McKelvey Hall 1010D (in the CSE department suite), email: guerin@wustl.edu
  • Office hours: Tuesday & Thursday 3:00-3:45pm, in-person in McKelvey 1010D. Additionally, Morning office hours (Tuesday & Thursday 8:00-8:45am) may be available, either in-person or over zoom, if requested at least the evening before.
• TA: TBD.
• Required resources: Submission of assignments and taking quizzes will require access to a computer and a stable Internet connection to be able to upload your answers through Canvas. You will need to make sure you are familiar with how to upload assignments in Canvas (there is a "test quiz" to allow you to figure out how to retrieve a quiz and upload your answer within the allotted time). Remote participation and attendance of zoom office hours will require access to a webcam and computer as well as again a reasonably stable Internet connection.
• Formatting guidelines for homeworks: Homeworks needs to be uploaded in Canvas as pdf files created using a word processor, editor, or other software that can produce typeset results, including math. Hand-written solutions are not acceptable, and a penalty may be assessed for homeworks that are uploaded as scanned copies of hand-written documents. Ideally, you should use LaTeX to generate your file, as it is the de facto standard for scientific publishing, and a basic template will be provided in the Formatting page that includes additional instructions on how to create a properly formatted homework assignment for you to turn in. An MS Word template will also be provided, but you are encouraged to use the LaTeX one to avoid making your life more difficult when having to type mathematical expressions.

• Late policy: A full description is available in the Late_and_Make-Up_Policies section of the wiki, but homeworks and preview problems are expected to be turned in by the start of the class on their due date by uploading them to the corresponding assignment in the course Canvas site. For all students, whether taking the class in-person or remotely (if provided), quizzes will be available on Canvas for a period of 72 hours (3 days), starting at the end of the class on the day indicated on the course Syllabus & schedule and with a "due date/deadline" set to 3 days later. For example, if quiz 1 becomes available at 5:30pm on September 15 after the end of class on that day, it must be submitted before 6:05pm on September 18. Students will be able to take their quiz any time during that 72 hours time period, but will only be allowed one attempt. Quizzes are time-limited to typically 30 minutes or less with an additional 5 minutes to allow students to take a picture of their completed quiz and upload it into Canvas. Canvas has been setup to only allow submissions within that time window once you start your quiz, so you will need to make sure that you are ready and have stable Internet connectivity prior to starting. A practice quiz is available on Canvas to allow you to try this out and make sure you can complete your uploads within 5 minutes (it may take a few rounds of practice, but 5 minutes should be plenty of time).

• Asking questions: You can obviously ask face-to-face questions during class and office hours (and are very much encouraged to do so), but the other and possibly better means to get answers to questions you come up while doing review problems, homeworks, or simply reviewing class material, is to use the Piazza site setup for the course (you may need to sign-up to be able to access it, if you registered late for the class and were not directly enrolled in 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 (though it is possible to post private questions when necessary). 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.

• ACADEMIC INTEGRITY: Please make sure you are familiar with Washington University Academic Integrity Policy, as it will be strictly applied.
  And see also the Collaboration Policy and Academic Integrity Violations section of the Course structure page.

COVID-19 Health and Safety Protocols

Students experiencing symptoms consistent with COVID-19 or concerned about a possible exposure should contact Habif Health and Wellness Center (314 935-6666) to arrange for testing as indicated. If instructed by Habif to quarantine or isolate, students should notify their instructor as soon as possible by forwarding the email they received from Habif. Any accommodation needs for COVID-related absence not covered in an instructor’s standard course policies should be discussed between the student and instructor.

While on campus, it is imperative that students follow all public health guidelines established to reduce the risk of COVID-19 transmission within our community. The full set of University protocols can be found at https://covid19.wustl.edu/health-safety/. This includes:

• Strongly recommended masking in indoor spaces. Masking remains a valuable tool in the mitigation of COVID-19, particularly in light of new and emerging variants. Students and instructors are encouraged to treat requests to mask with care and consideration, keeping in mind that some individuals may be at a higher risk, caring for others at a higher risk, or feeling less comfortable in a mask-optional environment. Based on monitoring of regional and campus conditions, a mask requirement may be implemented as needed. For current masking policies, see the WashU Together website.

• Maintaining physical distancing as needed. While distancing requirements have been removed for vaccinated students, those who are not fully vaccinated are strongly encouraged, for their own health, to maintain a distance of 6 ft from others in the classroom. If you are not able to be vaccinated or have conditions that may put you at increased risk of failed immunity and classroom activities would bring you in frequent proximity to other students, contact your instructor to discuss alternatives.

• Practicing healthy personal hygiene, including frequent handwashing with soap and warm water for at least 20 seconds and/or using hand sanitizer with at least 60% alcohol.

University-Wide Policies

Reporting Sexual Harassment

If a student discusses or discloses an instance of sexual assault, sex discrimination, sexual harassment, dating violence, domestic violence or stalking, or if a faculty member otherwise observes or becomes aware of such an allegation, the faculty member will keep the information as private as possible, but as a faculty member of Washington University, they are required to immediately report it to the Department Chair or Dean or directly to Ms. Cynthia Copeland, the University’s Associate Title IX Coordinator, at (314) 935-3411, cmcopeland@wustl.edu. 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

Disability Resources

WashU supports the right of all enrolled students to an equitable educational opportunity, and strives to create an inclusive learning environment. In the event the physical or online environment results in barriers to the inclusion of a student due to a disability, they should notify the instructor as soon as possible.

Disabled students requiring adjustments to equitably complete expectations in this course should contact WashU’s Disability Resources (DR), and engage in a process for determining and communicating reasonable accommodations. Because accommodations are not applied retroactively, DR recommends initiating requests prior to, or at the beginning of, the academic term to avoid delays in accessing accommodations once classes begin. Once established, responsibility for disability-related accommodations and access is shared by Disability Resources, faculty, and the student.

Disability Resources: http://www.disability.wustl.edu/; 3147-935-5970

Statement on Military Service Leave

Washington University recognizes that students serving in the U.S. Armed Forces and their family members may encounter situations where military service forces them to withdraw from a course of study, sometimes with little notice. Students may contact the Office of Military and Veteran Services at (314) 935-2609 or veterans@wustl.edu and their academic dean for guidance and assistance. See: https://veterans.wustl.edu/policies/policy-for-military-students/.

Preferred Name and Gender Inclusive Pronouns

Washington University in St. Louis recognizes that many students prefer to use names other than their legal ones to identify themselves. In addition, in order to affirm each person’s gender identity and lived experiences, it is important that we ask and check in with others about pronouns. This simple effort can make a profound difference in a person’s experience of safety, respect, and support. See: https://students.wustl.edu/pronouns-information/, https://registrar.wustl.edu/student-records/ssn-name-changes/preferred-name/.

Emergency Preparedness

Before an emergency, familiarize yourself with the building(s) that you frequent. Know the layout, including exit locations, stairwells and the Emergency Assembly Point (EAP). Review the “Quick Guide for Emergencies” that is found near the door in many classrooms for specific emergency information and instructions. For additional Information and EAP maps, visit emergency.wustl.edu. To ensure that you receive emergency notifications, make sure your information and cell phone number is updated in SIS, and/or download the WashU Safe app and enable notifications.

To report an emergency:
Danforth Campus: (314) 935-5555
School of Medicine Campus: (314) 362-4357
North/West/South and Off Campus: 911 then (314) 935-5555

Academic Integrity

Effective learning, teaching and research all depend upon the ability of members of the academic community to trust one another and to trust the integrity of work that is submitted for academic credit or conducted in the wider arena of scholarly research. Such an atmosphere of mutual trust fosters the free exchange of ideas and enables all members of the community to achieve their highest potential.

In all academic work, the ideas and contributions of others must be appropriately acknowledged and work that is presented as original must be, in fact, original. Faculty, students and administrative staff all share the responsibility of ensuring the honesty and fairness of the intellectual environment at Washington University in St. Louis.

For additional details on the university-wide Undergraduate Academic Integrity policy, please see: https://wustl.edu/about/compliance-policies/academic-policies/undergraduate-student- academic-integrity-policy/