ECE 428/CS 425/CSE 424 (Spring 2008)
Distributed Systems

Homework 1

As on all homeworks, students are encouraged to talk to study-buddies about
concepts taught in the course; however, should they discuss any homework 
problem, they should independently write up their solution, without reference
to any notes from such study sessions.

Assigned 1/24/08
Due by start of class on 2/7/08


(a) Problem 11.4 from 4th edition, or problem 10.4 from 3rd edition.

(b) Problem 11.7 from 4th edition, or problem 10.7 from 3rd edition.

(c) Problem 11.10 from 4th edition (3rd edition users please check with your
    classmates).

** The figure referred below in questions (d), (e), (f) and (g)
   is posted on the course web page, next to the link to this homework.

(d) Consider the attached figure. Assume that each process maintains
    a logical clock as a single integer value ("Lamport clock").
    Initial clock values are all initialized to 0. Using LC1
    and LC2 rules in section 11.4 of 4th edition (or section 10.4 of 3rd
    edition), determine the the timestamp of each event shown.

(e) Repeat the above problem for vector timestamps, using rules VC1
    through VC4 (from the section listed above) to determine the vector
    timestamps for each event shown.

(f) In the attached figure, are cuts C1 and C2 consistent?
    If you answer no for either of the cuts, explain why.

(g) In the attached figure, determine all the events that happened before
    event e8 (as per Lamport's Happened Before relation).

    Also determine the events that are concurrent with event e8.

(h) Problem 11.14 from 4th edition, or problem 10.14 from 3rd edition.