Assignment 4

Due Wednesday October 31, 2018 6:55pm via sakai


Please answer the questions precisely and concisely. Every question can be answered in one or at most a few sentences. I will not have the patience to read long paragraphs or essays and you may lose credit for possibly correct answers.

Note: submissions must be be plain text or pdf files or HTML within sakai. Other formats, such as Microsoft Word, Apple Pages, or Adobe InDesign will not be accepted.


Sanjay Ghemawat, Howard Gobioff, and Shun-Tak Leung, The Google File System, 19th ACM Symposium on Operating Systems Principles, October, 2003.
The definitive paper on GFS, which is also the model for HDFS (Hadoop Distributed File System). You only need to read the first 9.5 pages, up to but not including section 6.


Kevin Modzelewski, How We’ve Scaled Dropbox, Computer Science Colloquium, Stanford Center for Professional Development.
Watch at least the first 30 minutes.


Question 1

What are three advantages of using a large chunk size in GFS?

Question 2

Explain the role of the GFS master.

Question 3

As Dropbox’s design evolved, why did Dropbox split the original web server into two web servers? [What was the function of each server?]

Question 4

Why were notification servers added?

Question 5

Why was RPC-based communication added to the blockservers instead of having them talk to the database?