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DTS620S - DISTRIBUTED SYSTEMS - 2ND OPP SUPL - JAN 2023 |
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nAm I Bl A un IVE RSITY
OF SCIEnCE Ano
FACULTY OF COMPUTING AND INFORMATICS
DEPARTMENT OF COMPUTER SCIENCE
QUALIFICATION: BACHELOR OF COMPUTER SCIENCE, SYSTEMS ADMINISTRATION
QUALIFICATION CODE: 07BACS
LEVEL: 6
COURSE NAME: DISTRIBUTED SYSTEMS
COURSE CODE: DTS620S
DATE: JANUARY 2023
PAPER: THEORY
DURATION: 2 HOURS
MARKS: 70 {100%}
SECOND OPPORTUNITY/SUPPLEMENTARY EXAMINATION QUESTION PAPER
EXAMINER
MODERATOR
MS ALBERTINA SHILONGO
PROF. JOSE QUENUM
THIS QUESTION PAPERCONSISTSOF 3 PAGES(Including this front page)
INSTRUCTIONS
1) Answer ALL the questions on the answer scripts provided.
2) Be guided by the number of marks allocated when answering the questions.
3) Write clearly and neatly.
4) Show all your calculations.
5) Number your questions clearly.
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Question 1:
1. With examples, explain what is meant by distributed transparency.
(4)
2. Why is openness a major characteristic of distributed system design and what is it concerned
with?
(4)
3. List and explain 3 communication paradigms in distributed systems.
(6)
4. Explain what the stub is in RMI in distributed applications and the tasks it performs.
(6)
5. List and explain 4 main components/applications in RMI operation.
(4)
[Total: 24]
Question 2
1. Outline 4 advantages of HDFSover traditional databases.
(4)
2. Big Data Analytics is mainly used to monitor past data patterns and predict the future for
better service delivery and maximized profits in organizations. Explain how data analytics can
be applied to benefit the following industries:
(6)
a) Education:
b) Retail:
c) Banking
3. Explain Lamport's logical clocks algorithm and how its key ideas are applied in distributed
systems.
(4)
4. Explain the importance of scalability in distributed systems and explain concepts of hardware
and software scalability.
(6)
5. Explain the concept of synchronization amongst processes in distributed file systems during
message passing.
(4)
6. How would you use the 3 security mechanisms to implement security policies in distributed
systems?
(4)
7. Differentiate between Concurrency and Location transparency
(4)
8. List any three {3) characteristics of early distributed system devices.
(3)
[Total:25]
Question 3
1. Three processes Pl 1 P21 and P3 have formed a multicast group, sending three messages
Ml 1 Ml, and M3. Applying unordered reliable multicast demonstrates the possible
variations these messages will arrive at the receiver.
(6)
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2. A story is told of hotel XYZwhich was serving a popular breakfast on its ground floor. Due to
increased publicity the hotel guests become more and that forced the hotel to expand its
hotel floors by 5 more floors each with a capacity of 20 rooms from the initial 7 floors.
Subsequently, 2 more floors were added too. That extended the strain on the hotel kitchen
resources and their elevators were always congested during breakfast times mostly. Figure
1 is a representation of the hotel story and what each component of the hotel could
represent in terms of distributed systems
Storage
,,
" 1 Data
Processing
Network
Figure 1
Data 100110110
100101100
011010101
3. Select appropriate techniques in isolation or in combination to achieve a scalable
the solution to the given challenge in Figure 1.
a) Select appropriate techniques in isolation or in combination to achieve a scalable
the solution to the given challenge in Figure 1.
(8)
b) Explain the concept of a distributed file system and what such a system
aims to achieve when compared to local file systems.
(6)
c) Identify any key threats to security as faced in modern distributed systems.
(1)
[Total: 21]
Exam Ends
Total 70 Marks
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