We will study some of the key building blocks – such as synchronization primitives, group communication protocols, and replication techniques – that form the foundation of modern distributed systems, such as cloud-computing platforms or the Internet. We will also look at some real-world examples of distributed systems, such as GFS, MapReduce, Spark, and Dynamo, and we will gain some hands-on experience with building and running distributed systems.
CIS 505 is one of the core courses in the MSE program, and its final exam qualifies as one of the WPE-I exams in the PhD program.
Instructor:
Linh Thi Xuan Phan
Office hours: Wednesdays 1:00-2:00pm EDT
Location: OHQ and Zoom.
Lectures:
Time: Mondays/Wednesdays 10:15-11:45am
Location: Please see Piazza
(If you are on the waitlist and would like to attend the first few lectures, please email me.)
Teaching assistants:
| Yuxuan Zhang | Office hours: Mondays 1:30-3:00pm EDT |
| Karan Newatia | Office hours: Mondays 4:00-5:00pm EDT |
| Robert Gifford | Office hours: Tuesdays 11:00-noon EDT |
| John Hay | Office hours: Tuesdays 2:00-3:00pm EDT |
| | Wednesdays 4:00-5:00pm EDT |
| Yifan Cai | Office hours: Tuesdays 5:00-6:00pm EDT |
| Bill He | Office hours: Thursdays 11:00-1:00pm EDT |
| Zhilei Zheng | Office hours: Thursdays 7:00-9:00pm EDT |
| Neeraj Gandhi | Office hours: Fridays 10:00-11:00am EDT |
| Ziad Ben Hadj-Alouane | Office hours: Saturdays noon-1:30pm EDT |
| Sidharth Sankhe | Office hours: Sundays 7:00-8:00pm EDT |
Office hour timetable for Fall 2021. 
|
Office hours are held via OHQ and Zoom.
Course textbook:
Distributed Systems: Principles and Paradigms, 3rd edition (by M. van Steen and A. Tanenbaum; ISBN 978-1543057386).
You can get a digital version of this book for free; hardcopies are available, e.g., from Amazon.
Additional material will be drawn from selected research publications.
Prerequisites:
Either undergraduate networking or operating systems is required. You should also be comfortable with programming in C/C++.
Workload:
The course will involve three substantial programming assignments, a group project,
and two midterms.
Grading:
Your letter grade will be based on the programming assignments (35%), the group project (35%), the
midterm exams (25%), and participation and quizzes (5%).
We will be using Piazza for all course-related discussions.
Homework assignments and project are available for download; you can submit your solution online. If necessary, you can request an extension for your homeworks.
The goal of the special sessions is to provide you with tools and resources that might be useful for the assignments and project. See the special sessions page for more details.
 Amit Lohe, Bharath Jaladi, Liana Patel, and Prasanna Poudyal |
The Fall 2020 PennCloud Award went to Amit Lohe, Bharath Jaladi, Liana Patel, and Prasanna Poudyal for the overall best final project. The team presented a solidly designed, highly scalable, and robust PennCloud platform that offers strong conconsistency and fault-tolerance via primary-based replication with logging, checkpointing and recovery. The platform provides the complete set of required services with an elegant user interface, including a webmail service that supports both local and remote users, a storage service that supports uploading and downloading of large files in any format, and an admin console that supports viewing and easy controlling of the frontend and backend nodes' status and data. Besides the core functionalities, the platform also features useful extra-credit services, such as a discussion forum and a FIFO-ordered group chat system that are built on top of the KV store and the Paxos consensus protocol.
 Example services of the winning project. |
| Date | Topic | Details | Reading | Remarks |
|---|---|---|---|---|
| Sep 1 | Introduction [pdf] [video] | Course overview Policies |
Chapter 1 | HW0 |
| Sep 6 | Labor Day - No class | |||
| Sep 8 | Processes and threads
[pdf]
[video] |
Basic concepts The UNIX model Implementation in the kernel |
Chapter 3.1 (Sections 1+2) | HW0 due (on 9/10) |
| Sep 13 | System calls [pdf] [video (part 1)] [video (part 2)] | System calls The file API Kernel entry/exit |
HW1 | |
| Sep 15+20 | Concurrency control [pdf] [video (part 1)] [video (part 2)] | Synchronization primitives Race conditions, critical sections Deadlock and starvation |
||
| Sep 22 | Synchronization [pdf] [video] |
Semaphores Classical synchronization problems Monitors and condition variables |
Hoare monitors; Mesa monitors | |
| Sep 27 | Communication [pdf] [video] |
Sockets Socket programming Handling multiple connections |
Chapters 4.1+4.3 + 3.1 (Section 3) | HW1 due |
| Sep 29 | Remote Procedure Calls [pdf] [video] |
Programming model Stub code; marshalling; binding Handling failures |
Chapters 4.2+8.3 | HW2 |
| Oct 4 | Naming [pdf]
[video] |
Kinds of names; name spaces The Domain Name System LDAP |
Chapter 5 | |
| Oct 6+11 | Clock synchronization [pdf]
[video (part 1)] [video (part 2)] |
Logical clocks Distributed mutual exclusion NTP |
Chapters 6.1–6.3 | HW2MS1 due (on 10/8) |
| Oct 11 | Last day to drop | |||
| Oct 13 | First midterm exam | |||
| Oct 14–Oct 17 | Fall break | |||
| Oct 18 | Distributed coordination | Distributed mutual exclusion Leader election Bully algorithm; token ring |
Chapter 6.4 | HW2MS2 due (on 10/19) |
| Oct 20 | Group communication | Reliable multicast IP multicast FIFO, causal and total ordering |
Chapter 8.4 | |
| Oct 25 | Algorithms for FIFO, causal and total ordering | HW3 | ||
| Oct 27 | Replication | Primary/backup protocols Quorum protocols Sequential and causal consistency Client-centric models |
Chapter 7 | Project |
| Nov 1 | Bigtable and Project | Bigtable case study Project overview |
[Bigtable] | |
| Nov 3 | Fault tolerance | 2PC and 3PC Logging and recovery Chandy-Lamport algorithm |
Chapters 8.5+8.6; [Chandy-Lamport] | HW3 due (on 11/5) |
| Nov 8 | State-machine replication | Failure models The Consensus problem Paxos |
Chapters 8.1+8.2; [Paxos] | |
| Nov 8 | Last day to withdraw | |||
| Nov 10 | Non-crash Fault Tolerance | The Byzantine Generals problem Impossibility results Solutions |
[BFT] | |
| Nov 15+17 | Distributed file systems | NFS Coda Disconnected operation |
Chapter 2.4.2; [Coda] | Nov 22 | Google File System | Google cluster architecture Reading and writing in GFS Consistency and fault tolerance |
[Cluster] [GFS] |
| Nov 24 | Thanksgiving break - no class (Friday schedule) | |||
| Nov 29 | MapReduce | MapReduce programming model System architecture |
[MapReduce] | |
| Dec 1 | Spark | Differences to MapReduce RDDs Case study: PageRank |
[Spark] | |
| Dec 6 | DHTs and Dynamo | Distributed hash tables The CAP dilemma Amazon Dynamo |
[Dynamo] | |
| Dec 8 | Second midterm exam | |||
| Dec 11–Dec 14 | Reading days | |||
| Dec 15–Dec 22 | Project demos and reports | |||