Topics

• Distributed File Systems
• Consistency in real implementations

Group size

This exercise can be performed in groups of max 3 people.

Assignment

You have two main tasks in this assignment:

1. Take a look at the Coda distributed file system (http://www.coda.cs.cmu.edu/). Research the documentation and papers about Coda. You do not need to install Coda,  but if you are interested, please feel free to experiment with it. You need to answer the following questions:

• a. What consistency models does Coda support?
• b. What algorithms are used to implement the consistency models?
• c. What kind of data replication mechanisms does Coda use?

Note that it is not necessary to read all of the articles, just skim through some and locate the most relevant ones.

 2. Investigate one existing cloud-based storage service, for example, Google Docs, DropBox, iDisk, Box.net, Sugarsync, etc.

• a. Can you find out what consistency model that service uses? Even if not, explain how you searched for this answer.
• b. Experiment with storing data on that service and attempt to break the data consistency.