Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Midterm Exam
CSc72010
Each question counts 20 points.
1. Given an automaton with an output parent(x:NodeID) and a network graph
connecting the automata. For each possible execution of the network of automata,
consider another graph whose nodes correspond
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
What problems does a mobile adhoc architecture have to solve? In each case, why dont
standard wireline solutions work (or do they)?
Finding neighbors/links
Minimizing collisions/maximizing bandwidth
Conserving battery
Allocating addresses
Forwarding mess
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Midterm
Chapter 8, sections 14
8.1: Definition of automaton
8.2: Composition
Understand theorems, but I will not require you to state or prove them.
8.3: Fairness
Understand theorems
8.4: This is just a hint, you should read it
Section 8.5 pp 216219
Inv
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Spanning Tree
Some facts about spanning trees in undirected graphs:
Acyclic
Number of edges is 1 less than the number of nodes
Connected
Root has no parent
Any connected subgraph of a graph with (number of nodes)1 edges is a tree
Applications
Broadcast
C
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Simpleminded Clock Sync
ICMP Protocol (types 1314): Send a message with your local time and a unique message
id. The receiver responds with the unique id, your time, his time, and a new id. You
respond with your time & his time. And continue forever.
Fi
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Clocks:
Definition of causal ordering, be able to describe an order of events consistent with a
flow diagram
Why global state is hard to determine, multiple consistent global states in terms of order
of events in a flow diagram
Theorem 18.1
Clock synchron
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
CSc72010
General Asynchronous Networks
Reading
Lynch, Sections 15.215.4
Introduction
Basic tasks:
Broadcast
Convergecast
Loopfree communication
In this section of the course, we look at important proof techniques on simple algorithms.
Assume a general d
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
CSc72010
Leader Election
Reading: Chapters 14 (Asynchronous Network Model), 15.1 (Leader Election in a Ring)
Importance of leader election algorithms
The basic solution to cycles in an Ethernet LAN is for the switches to run the spanning tree protocol (ST
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Csc72010
Parallel and Distributed Computation and Advanced
Operating Systems
Homework 1
For Thursday, February 22
1. Write a tioa that implements the sliding window algorithm.
Show that the algorithm has the following desirable properties:
a. Messages are
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Csc72010
Parallel and Distributed Computation and Advanced
Operating Systems
Homework 2
New due date: Thursday, March 8
Reading
Distributed Algorithms, Chapter 8 and Chapter 1415.1
Chapters 3 and 4 have some proofs for synchronous systems that may help y
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Csc72010
Parallel and Distributed Computation and Advanced
Operating Systems
Homework 3
For Thursday, March 15
Reading
Distributed Algorithms, Chapter 15.5
Exercise
Show liveness properties for the Sliding Window and Learning Bridge protocols.
Use the sli
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Csc72010
Parallel and Distributed Computation and Advanced
Operating Systems
Lecture 2
Notes based on Peterson and Davies, Chapter 2
Nodes
CPU


Cache
Network Adaptor (To network)

Memory
CPU speeds increase faster than memory speeds: networking is
Parallel and Distributed Computation and Advanced Operating Systems
CSC 72010

Fall 2013
Csc72010
Parallel and Distributed Computation and Advanced
Operating Systems
Lecture 1
Course Description
Whats different about a distributed system?
Bank example
If we think about programming transactions coming into a centralized bank computer, we
can a