CMPSCI 677: Homework 2
Due: In-Class, Tuesday, March 1 2005
Off-campus students: one week from when you view Lecture 7
Web posted: Tue Feb 22, 12pm
- RPC
- Give an example application for each of the following RPC
semantics.
- atleast-once
- atmost-once
- exactly-once
- atmost-once multicast
- Consider the case of orphaned computations at the server
and use of at-most once semantics RPC.
Describe briefly how the client and server should be implemented
to handle orphan computations for the at-most once semantics.
- Communication
Suppose 3 machines can communicate as shown below,
M1 <--> M2 <--> M3
An instant messenger application needs to exchange data
between M1 and M3, but all messages go via M2.
What kind of communication model will you use?
i.e: persistent/transient asynchronous/synchronous and
describe briefly how you will realize/implement it.
Also, describe what kind of reliability and tradefoffs will your
system have?
- Token Bucket
Consider two flows that both share a transmission link
of capacity 'R' Kbps.
- Use a set of token buckets to regulate
their average traffic in the ratio r1:r2 and burst sizes
in the ratio b1:b2.
State what is the inequality that needs to be
satisfied so that no packets are dropped after passing
the token buckets (i.e., packets do not get dropped because they
exceed the transmission capacity)
- Give a solution for the values of (r,b) for each bucket, if the
r1:r2 ratio is 1:3, b1:b2 ratio is 2:3 and R=300 Kbps
- Design considerations
- Last slide of Lecture 2 describes the design consideration of the
Email system along several parameters. Similarly, pick any other
distributed system and list its design considerations and describe
each in a single sentence.
- Give an example each of system where pure-pull, pure-push and combination
of push and pull are appropriate.
Prashant Shenoy
Puru Kulkarni