Download AKTU B-Tech 7th Sem 2016-2017 NCS 701 Distributed System Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 7th Semester (Seventh Semester) 2016-2017 NCS 701 Distributed System Question Paper

Printed Pages: 3 NCS - 701
(Following Paper ID and Roll No. to be ?lled in your
Answer Books)
Roll No.
B.TECH ,
Regular Theory Examination (Odd Sem - VII), 2016-17
DISTRIBUTED SYSTEM
T ime : 3 Hours Max. Marks : 100
Section - A
1. Attempt all parts. All parts carry equal marks. Write
answer of each part in short. (10X2=20)
a) List out the main challenges of distributed systems.
b) What are logical clocks? Why does a logical clock
need to be implemented in distributed systems?
c) What do you mean by mutual exclusion in
distributed system? What are the requirements of
a good mutual exclusion algorithm?
(1) De?ne deadlock detection in distributed systems.
e) List out some issues in distributed ?le system.
0 State Byzantine agreement problem.
g) What do you mean by agreement protocol?
h) Compare and contrast static and dynamic vote
protocols.
701/12/2016/12840 (1) [P.T.O.

NCS - 701
i) Define fault and failure. What are different
approaches to fault-tolerance?
j) What are the different validation conditions for
optimistic concurrency control?
Section - B
Note: Attempt any ?ve questions from this section
(5>< 10:50)
i) Discuss the limitations of Lamport?s logical clock
with suitable example.
ii) Give the Chandy-Lamport?s global state recording
algorithm.
Discuss casual ordering of messages. Give one algorithm
which can order the messages according to causal
dependencies.
i) Differentiate between token and non token based
algorithms.
ii) What are the deadlock handling strategies in
distributed file systems? What is control
organization for distributed deadlock detection?
Discuss an algorithm which can remove phantom
deadlock.
What are agreement protocols? Explain Byzantine
agreement problem, the consensus problem and
interactive consistency problem.
Describe in detail:
a) Dynamic voting protocols.
b) Method to obtain consistent set of checkpoint.
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NCS - 701
De?ne forward recovery and backward recovery. List
advantages and disadvantages of forward recovery. Explain
two approaches of backward-error recovery.
Explain design in use in distributed shared memory and
also write algorithm for implementation of shared
memory.
i) What are the goals of distributed transaction?
Distinguish between ?at and nested transaction
along with its structure. ?
ii) Explain optimistic concurrency control.
Section - C
Note: Attempt any two questions from this section.
10.
11.
12.
?(2 x 1 5:3 0)
Describe Lamport - shostak - pease algorithm. How does
vector clock overcome the disadvantages of Lamport
clock? Explain with an example.
Discuss the following: .
a) Performance metric for distributed mutua
exclusion algorithms.
b) Obermarck?s Path ? Pushing algorithm.
Write short notes on:
a) F lat and nested transaction
b) ZPL and Strict 2PL.
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