Distributed Systems (HS 2022)
Note: This course is part of the course "Computer Systems" (252-0217-00L), but can also be taken as a standalone course: "Distributed Systems" 227-0555-00L. For the full course held together with Professor Roscoe visit the corresponding webpage and the corresponding internal moodle.
This course introduces the fundamentals of distributed systems. We study different protocols and algorithms that allow for fault-tolerant operation, and discuss practical systems that implement these techniques. The objective of the course is for students to understand the theoretical principles and practical considerations of distributed systems. This includes the main models of fault-tolerant distributed systems (crash failures, byzantine failures, and selfishness), and the most important algorithms, protocols and impossibility results. By the end of the course, students should be able to reason about various concepts such as consistency, durability, availability, fault tolerance, and replication.
Topics: client-server, serialization, two-phase protocols, three-phase protocols, paxos, two generals problem, crash failures, impossibility of consensus, byzantine failures, agreement, termination, validity, byzantine agreement, king algorithm, asynchronous byzantine agreement, authentication, signatures, reliable and atomic broadcast, eventual consistency, blockchain, cryptocurrencies such as bitcoin and ethereum, proof-of-work, proof-of-*, smart contracts, quorum systems, fault-tolerant protocols such as piChain or pbft, distributed storage, distributed hash tables, physical and logical clocks, causality, selfishness, game theoretic models, mechanism design.
Course pre-requisites: None.
Course language: English.
Lecture by Roger Wattenhofer, Monday or Friday 10.15-12.00 @ CAB G 61.
Videos Videos of the lectures can be found on the ETH Video Portal.
Exercises Friday 14.15-16.00 @ HG D 5.3 lead by Valerio Torsiello (vtorsiello@student.ethz.ch). Exercises only take place in the weeks with a lecture. Recordings of the exercise sessions can be found here.
Bonus See here for description of the bonus task, deadline for submissions, etc.
Organization by Yann Vonlanthen.
Corona information: We will follow Corona guidelines from the main ETH administration. Check here for more details.
Script 2022: You can find the tentative script for 2022 here.
Word of advice from the professor: Instead of attending this course, you can also just read The Saddest Moment by James Mickens, the guy who continuously tried to convince me that having vodka shots at a local Denny's at 3am is how I should spend my nights. Just reading Mickens will not give you any credits though.
News
| 19.09.2022 | Course website updated. |
| 20.10.2022 | Due to unforseen circumstances, the first two lectures of the course have been moved to 21.10 and 24.10 respectively. The first exercise session will be held on 28.10. |
| 27.11.2022 | Due to the illness of Prof. Wattenhofer, a TA (Yann Vonlanthen) will give tomorrow's lecture. |
| 28.11.2022 | The bonus task has been published. |
| 01.12.2022 | The exercise session will be held @ HG D 5.3 starting this week. |
| 04.12.2022 | Due to the illness of Prof. Wattenhofer, tomorrow's lecture is cancelled. |
| 08.12.2022 | Due to the illness of Prof. Wattenhofer, until further notice lectures will be held by TAs. |
| 16.12.2022 | Chapter 21: We did not discuss Section 21.4, and regarding Section 21.3, we only discussed 21.14 -- 21.16 and Figure 21.21 (but not the analysis of the B-Grid). Only the topics discussed in class are relevant for the exam. |
| 12.01.2023 | By popular request, we are publishing the (outdated) clicker questions. |
Lecture Material
Lecture material and exercise sheets will be uploaded here as the lecture progresses. Note that chapter numbers are aligned with the course "Computer Systems".
| Title | Lecture Notes | Exercises | Additional Material |
|---|---|---|---|
|
Chapter 14 Introduction Date: 21-October-2022 |
--- | --- | |
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Chapter 15 Fault Tolerance & Paxos Date: 21-October-2022 |
--- | Recording from 2020 | |
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Chapter 16 Consensus Date: 24-October-2022 |
Exercises Solutions |
Exercise Slides Recording from 2020 |
|
|
Chapter 17 Byzantine Agreement Date: 14-November-2022 |
--- | Recording from 2020 | |
|
Chapter 18 Broadcast & Shared Coins Date: 18-November-2022 |
Exercises Solutions |
Exercise Slides Recording from 2020 |
|
|
Chapter 19 Consistency & Logical Time Date: 21-November-2022 |
--- | Recording from 2020 | |
|
Chapter 20 Time, Clocks & GPS Date: 25-November-2022 |
Exercises Solutions |
Exercise Slides Recording from 2020 |
|
|
Chapter 23 Eventual Consistency and Bitcoin Date: 28-November-2022 |
--- | Recording from 2020 | |
|
Chapter 24 Advanced Blockchains Date: 02-December-2022 |
Exercises Solutions |
Exercise Slides Recording from 2020 |
|
|
[Cancelled] Date: 05-December-2022 |
--- | --- | --- |
|
Chapter 22 Distributed Storage Date: 09-December-2022 |
Exercises Solutions |
Exercise Slides Recording from 2020 |
|
|
Chapter 25 Game Theory Date: 12-December-2022 |
--- | Recording from 2020 | |
|
Chapter 21 Quorum Systems Date: 16-December-2022 |
Exercises Solutions |
Recording from 2020 Recording (second half of the lecture) Cascade and Consensus on Demand Slides Cascade Consensus on Demand Exercise Slides |
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|
Advanced Topics in Distributed Systems Date: 19-December-2022 |
--- | --- |
Recording Dfinity Internet Computer Approximate Agreement |
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No lecture Date: 23-December-2022 |
--- | --- | --- |
Exam Preparation
To get an idea for the style of questions in the exam, you may consult exams from previous years: HS09, HS10, HS11, HS12, HS13, HS14, HS15, HS16, HS18, HS19, HS20, HS21. Beware that the topics covered have shifted around a little over the years, so some older exams have questions about topics that are not in the lecture anymore. Some of the older exams are in German, but this year’s exam is in English.