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00000CS4071219dame:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
Seventh semester B.Tech examinations (S), September 2020

Course Code: CS407
Course Name: DISTRIBUTED COMPUTING

PART A
Answer all questions, each carries 4 marks.

In what all aspects distributed systems are better than centralized systems? Give
examples of two applications for which distributed systems will be more
suitable.

What are the different communicating entities in a distributed system?
Distinguish between synchronous and asynchronous distributed systems.
Describe the architecture of Skype overlay network.

Explain the characteristics of multicasting.

What is the role of Vice and Venus in AFS?

Does ring based mutual exclusion algorithm satisfy the happened before
ordering criteria? Illustrate with an example.

What are the criteria for evaluating the performance of a mutual exclusion
algorithm?

Explain the basic time stamp ordering rule.

Distinguish between forward and backward validation.

PART B
Answer any two full questions, each carries 9 marks.
Explain processor pool model with diagram.

Discuss the challenges in designing a distributed system.
Illustrate the security model for distributed systems.

Identify the failure category in the following events and define it:
i.Dropped messages

ii.Corrupt/duplicate data

iii. Delayed transmission

Explain with an example the distributed service as a utility.

How can processes and their interactions be secured in a distributed system?

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Duration: 3 Hours

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