Distributed Systems Course (fall 2014/2015)

Lecturer: Konrad Iwanicki
Assistants: none
Lectures: Wednesday, 2:15 PM - 3:45 PM, Room 3230
Lab classes: Wednesday, 4:15 PM - 5:45 PM, Room 3045
Final exam: Wednesday, January 21, 2:15 PM - 3:45 PM (may be shorter), Room 3230

This (fifth) edition of the course consists of two components: lectures and lab classes. The lectures cover the principles, advanced concepts, and technologies of distributed systems, including communication, replication, fault tolerance, and security. The objective of the lab, in turn, is to give every student a chance to design, implement, and evaluate his own distributed system in the area of cloud computing. The course is recommended for graduate students attending the distributed systems seminar and following the DOS Master's track, as well as for other students interested in computer systems. The course may be given in English.

Passing Rules

To pass the course, a student has to score at least 60 out of a total of 100 points and pass the lab (see below). The points can be scored for:

  • lab assignments: up to 50 points
  • a written exam at the end of the semester: up to 50 points

The final grade is calculated as follows:

Points 0-51 52-59 60-67 68-75 76-83 84-91 92-...
Grade 2 (fail) 2+ (fail) 3 3+ 4 4.5 5

Lab Rules

The goal of the lab is to allow each student build her own distributed system. The building process will consist of three assignments and one colloquium. To pass the lab, each student has to score a total of at least 26 points and a given number of points per each assignment. The breakdown of the scores and deadlines is as follows:

What When How many points Min. required points
Colloquium October 8, 2014, 16:00 CEST 5 0
Assignment 1 November 2, 2014, 23:59 CET 10 6
Assignment 2 December 28, 2014, 23:59 CET 35 18
Assignment 3 February 6, 2015* 15 0

This is the final deadline. There are no extensions, even for spare lecture points. The assignment should be presented to the lecturer by this deadline. It is neccessary to schedule an appointment earlier. Failure to do so will result in not having the assignment graded.

At the beginning of the course, students may decide if they want to work on the assignments individually or in pairs. No larger groups will be allowed. The decision cannot be changed during the semester (after the colloquium). The lecturer will not regard any conflicts within pairs as circumstances affecting grades. In other words, if you work in a pair, choose your partner well.

Assignment solutions have to be handed in on time by submitting e-mails with topic “[DS2014] Solution X” to the lecturer (where X can be 1, 2, or 3). Since the lecturer receives an excessive number of e-mails, e-mails with different topics may be ignored. Moreover, each day of delay in submitting a solution results in multiplying the scores received for the solution by 0.9. Normally, the delay must not be more than 7 days, after which an assignment is considered as failed (the student receives 0 points). However, each day a student participates in both a lecture and a lab gives the student one extra day of delay (in this day, the points are not multiplied by 0.9). No future days during which the student intends to participate will be counted toward the reduction. For students working in pairs, the reduction will be counted as the average of the lectures attended by each of the participants (rounded if necessary).

It is allowed to talk about your ideas on solving the assignments with your colleagues. It is NOT allowed to show, share, exchange code (in any form) without a prior permission from the lecturer.

Exam Rules

The exam covers the lecture topics. It consists of a series of questions. Each question has three subquestions with binary (TRUE/FALSE) answers. A students scores a point for a question only if the answers to all subquestions of the question are correct. Conversely, if an answer to any subquestion of the question is incorrect, no point is given for the entire question. Note that these scoring rules are really demanding (cf. the scores for 2012/2013).

Lecture Topics and Schedule

Since this is still a developing course, this year's lectures will be given mostly based on a book by my PhD adviser and the head of my former research group: Maarten van Steen and Andrew S. Tanenbaum, “Distributed Systems: Principles and Paradigms,” Second Edition, Prentice Hall, 2007, 702 pages, ISBN 9780132392273. Purchasing the book is not mandatory as the lecture slides will be available here. There will be a few lectures with an extra material, though.

Date Topics Slides
October 1, 2014 Introduction:
goals of distributed systems, common types of distributed systems
lecture 01
October 8, 2014 Architectures:
architectural styles, system architectures, self-management
lecture 02
October 15, 2014 Processes:
threads, virtualization, clients & servers, server clusters, code migration
lecture 03
October 22, 2014 Communication:
fundamentals, remote procedure call, message-oriented communication, stream-oriented communication, multicast communication
lecture 04
October 29, 2014
November 5, 2014 Naming:
basic terms and definitions, flat naming, structured naming, attribute-based naming
lecture 06-07
November 12, 2014
November 19, 2014 Synchronization:
clock synchronization, logical clocks, totally-ordered multicast, causally-ordered multicast mutual exclusion, global positioning of nodes, leader election
lecture 08-09
November 26, 2014
December 3, 2014 Replication and Consistency (Part I):
replica management, continuous consistency, data-centric consistency models, consistency protocols
lecture 10 (selected slides)
December 10, 2014 Canceled.
Participating in a PhD committee in Amsteram
December 17, 2014 Fault Tolerance (Part I):
failure models, failure masking, failure detection, reliable client-server communication, atomic multicast, two-phase commit, three-phase commit, checkpointing, logging, recovery, agreement in faulty systems
lecture 11
January 7, 2015 Fault Tolerance (Part II):
agreement in faulty systems (continued), Paxos
lecture 12
January 14, 2015 Replication and Consistency (Part I):
CAP theorem, PACELC, eventual consistency, conflict-free replicated data types, client-centric consistency models
lecture 13
January 21, 2015 FINAL EXAM

Lab Topics and Schedule

The schedule of lab classes is as follows:

Date Materials
October 1, 2014 Scenario 01
October 8, 2014 Scenario 02
October 15, 2014 Scenario 03
October 22, 2014 Scenario 04
October 29, 2014 Individual work; questions and answers
November 5, 2014 Scenario 05
November 12, 2014 Scenario 06
November 19, 2014 Scenario 07
November 26, 2014 Scenario 08
December 3, 2014 Scenario 09
December 10, 2014 Canceled
December 17, 2014 Scenario 10
January 7, 2015 Scenario 11
January 14, 2015 Scenario 12
January 21, 2015 Individual work; grading Assignment 2, questions and answers

Past Exams

Below, you can find the questions from past exams:

Year Exam Set Participants Points
Course Exam % Available Min Avg Med Max
2013/2014 Final (test) 16 16 100 25 11 14.69 13 21
2012/2013 Final (test) 34 34 100 25 3 10.33 10 22
2011/2012 Final 36 34 94.4 50 10 29.85 30.5 49
2010/2011 Part II 26 21 80.8 25 3.75 16.27 13.5 24.25
2010/2011 Late Part I 26 11 42.3 25 13.75 21.6 21.25 24.75
2010/2011 Early Part I 26 17 65.4 25 9.25 14.9 13.5 22