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Reg No.: Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SEVENTH SEMESTER B.TECH DEGREE EXAMINATION, DECEMBER 2018

Course Code: CS407
Course Name: DISTRIBUTED COMPUTING
Max. Marks: 100 Duration: 3 Hours
PART A
Answer all questions, each carries 4 marks. Marks
1 List any 4 issues in the design of a distributed system. (4)
2 What is the need of safety and liveness as requirements in an Election (4)
algorithm?
3 Explain the key techniques used for indirect communication. (4)
4 Why Skype is called an Overlay network? (4)
5 Evaluate the performance of Maekawa’s voting algorithm with respect to fault (4)
tolerance
6 Why is “send_group” group communication primitive preferred over “send” (4)
primitive?
7 What is the difference between two-phase locking and strict two-phase locking (4)
in transactions?
8 What do you mean by Vice and Venus in AFS?. What are their roles? (4)
9 State the rules for committing of nested transactions. (4)
10 Define mobile agents. How can they be potential security threats? (4)
PART B

Answer any two full questions, each carries 9 marks.
11 a) What are the two variants of the interaction model in distributed systems? On (4)
what points do they differ?
b) Describe any 4 key architectural patterns used in distributed systems. (5)
12 2) List and explain the different types of communication paradigms used within (6)
distributed systems.
b) A distributed system is defined as one in which hardware or software (3)
components located at networked computers communicate and coordinate their
actions only by passing messages, What are the consequences of defining a
distributed system in this manner?

13 a) Write notes on mobile and ubiquitous computing. (4)

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