Distributed Systems 2

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643 B. E. VIllth Semester Computer Science Examination DISTRIBUTED SYSTEM Paper-CSE 454-C Time allowed: 3 hours

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Note: Attempt any five questions.

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What is a network operating system? Differentiate it from a distributed operating system. 10

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What is meant by distributed systems? What are the advantages of distributed systems· over independent PC's? 10

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For each of the following applications do you think atleast once semantics or atmost once semantics is best. Discuss : (i) Reading and writing files from a file server. (ii) Compiling a program (iii) Remote Banking.

(b)

3. (a)

(b)

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How 2,., atomic broaucast h: u-.;ed to manage grou!1 membership? 5 Name atleast three sources of delay that can be introduced between WWV broadcasting the time and the processors in a distributed system setting their internal clocks? 6 Give the full algorithm for whether an attempt to lock a file should succeed or fail. Consider both read and write locks, and the possibility that the file was unlocked, read locked or write locked. 14 P-2 (Q-8) (04)

P.T.O.

4.

Discuss the issue of fault tolerance in distributed systems. Also discuss three approaches towards fault tolerance. 20

5. Discuss the network file system architecture and implementation in detail.

20

6. Discuss the page based distributed shared memory in detail. ?n 7. (a)

A university is installing DCE on all computers in campus. Suggest atleast two ways to divide the machines into cells.

(b)

10

Mach has a system call that allows a process to

request that non-Mach traps be given to a special handler, rather than causing the process to be killed. What is 8. Write shortthis notes on : call good for? 10 system DisuibuLt:J file system components in client Kernel (ii)

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in DCE.

10

Distributed shared memory in Mach.

10