 |
DSA621S - DISTRIBUTED SYSTEMS AND APPLICATIONS - 2ND OPP - JAN 2023 |
|
|
1 Page 1 |
▲back to top |
nBmlBIA UnlVERSITY
OF SCIEnCE AnDTECHnOLOGY
FACULTYOF COMPUTING AND INFORMATICS
DEPARTMENT OF COMPUTER SCIENCE
QUALIFICATION: Bachelor of Computer Science
QUALIFICATION CODE: 07BACS
COURSE: Distributed Systems and Applications
DATE: January 2023
DURATION: 3 Hours
LEVEL: 6
COURSECODE: DSA621S
SESSION: 2
MARKS: 92
SECOND OPPORTUNITY/SUPPLEMENTARY EXAMINATION QUESTION PAPER
EXAMINER:
I Prof. Jose G. Quenum
MODERATOR:
I Prof. Dharm Singh Jat
This paper consists of 1 page
(excluding this front page)
INSTRUCTIONS
1. This paper contains 5 questions.
2. Answer all questions on the exam paper.
3. Marks/scores are provided at the right end of each question
4. Do not use or bring into the examination venue books, mobile devices and other materials
that may provide you with unfair advantage. Should you be in possession of one right now,
draw the attention of the examiner officer or the invigilator.
5. NUST examination rules and regulations apply.
PERMISSIBLE MATERIALS
Calculator
|
|
2 Page 2 |
▲back to top |
|
|
3 Page 3 |
▲back to top |
DSA621S
First Exam (continued)
January 2023
Question 1 ..................................................................
[12 points]
Consider the following Byzantine Generals problem with seven processes: P1, P2, P3, P4, Ps,
P6 and P7 . Pi is the commander and the rest of the processes are its lieutenants. P1 sends the
value Oto P2, P3 and P4 , while it communicates the value 1 to the other processes. Assuming
that processes P3 and P6 were also faulty during the algorithm, what is the final decision?
Question 2 ..................................................................
[20 points]
Consider a distributed system with twelve (12) processes Pi to Pi2 • Note that a process with a
higher identifier has better resources than one with a lower identifier. Consider the following
scenarios during an election algorithm involving the processes:
1. the initiator of the election P3, using the ring algorithm 1, crashed during the election
phase;
2. process Pi2 crashed after forwarding the election message using the ring algorithm 2.
For each scenario, discuss the outcome of the election
Question 3 ..................................................................
[25 points]
Present the architecture of a Hadoop Distributed File System (HDFS)cluster. Discuss in detail
the read and write operations using HDFS.
Question 4 ..................................................................
[20 points]
(a) Discuss in detail the read operation in Network File System (NFS)
[8]
(b) Most distributed file systems involve a remote procedure call (RPC)between the client
[12]
module and the server. Discussthe impact of the call semantics on a write-only scenario.
Question 5 ..................................................................
[15 points]
Consider a kafka cluster containing three (03) brokers, C L 1, C L2 and C L 3 . Each topic con-
tains three (03) partitions with a replication factor of two (02) i.e., each partition is replicated
once (on another broker). Using a diagram representing the cluster illustrate how a producer
submits messages to the cluster and a consumer group consumes such messages. You will be
explicit about how the partitions are handled.
Page 1 of 1
End of Exam
|
|
4 Page 4 |
▲back to top |
c~
ili
"""""" Unl'ffRSITY
::1;:St;Enci: Rno
~.iWirtrihoek,
r.,\\MJBI~ ;
i
T';rt.;:1fH:~'GY
J
2022-10-18
!
co_~~~!::R l
FACULT(Yff rnMPU'fiNG& !fJtORr"1ATICS
DEPARTMEMT:
SCIEN(E
1