22C: 166 Distributed Systems and Algorithms
Homework 2, Total points = 60
Assigned 9/18/08 due 9/25/08 in class
Please submit typewritten solutions. Late assignments will not be accepted
without prior approval.
Question 1. (5 points) Chapter 4 Exercise 5
Question 2. (15 points) Chapter 4 Exercise 12
(Remember, writing a solution is not adequate. You have to justify why you
solution will work, i.e. the burden of proof is always on you)
(Oops! This was a part of homework 1. Please solve the next problem
(Chapter 4, Exercise 13 instead)
Question 3. (5+5 points) Chapter 5 Exercises 10, 11
Question 4. (10 points) Chapter 6 Exercise 3
Question 5 (10 points) This question asks you to study reachability.
Reachability is a liveness property. A global state S’ is reachable from another
global state S, if there exists a valid computation (i.e. a sequence of states and
state transitions) that leads the system from S to S’.
In a computation running on a distributed system, let S be the initial state,
and S’ be a terminal state (a state in which the system does not have any eligible
action, and all channels are empty). Also, assume that S’ is reachable from S.
Will the distributed computation always terminate?
Explain your answer. If necessary, use an example to justify your point.
Question 6 (10 points) Chapter 7, Exercise 2