DISTRIBUTED SYSTEM 2019 RCAE35 MCA 5th Sem AKTU

Printed Pages: 02Sub Code: RCAE35

Paper Id: 214509Roll No. _____________________

MCA

(SEM V) THEORY EXAMINATION 2018-19

DISTRIBUTED SYSTEM

Time: 3 Hours Total Marks: 70

Note: 1. Attempt all Sections. If require any missing data; then choose suitably.

SECTION A

1. Attempt all questions in brief. 2 x 7 = 14

(a) Write down the importance of distributed system?

(b) What are the issues in distributed system?

(c) Define Transparency. What are its types?

(d) What do you mean by clock skew and clock drift?

(e) What are the ACID properties of a transaction?

(f) What are the advantages of nested transaction?

(g) What is wait-for-graph?

SECTION B

2. Attempt any three of the following: 7 x 3 = 21

(a) Define distributed system? Describe the main characteristics of distributed systems. Give two examples of distributed system.

(b) Define Vector clocks? Explain with the help of implementation rule of vector clocks, how they are implemented?

(c) Define causal ordering of messages. Give any algorithm which can order the messages according to casual dependencies.

(d) Explain the Ricart-Agarwal algorithm for mutual exclusion. How many messages per critical section execution are required? (Assume there are N sites).

(e) Discuss the Chandy-Lamport’s global state recording algorithm.

SECTION C

3. Attempt any one part of the following: 7 x 1 = 7

(a) Define deadlock? Discuss the necessary conditions for deadlock in distributed system? Describe the deadlock handling strategies in distributed system.

(b) Define a token based algorithm for mutual exclusion. Describe its performance on important metrics.

4. Attempt any one part of the following: 7 x 1 = 7

(a) Discuss mechanism for building distributed file system. Explain data access actions in distributed file system.

(b) Define livelock problem in message passing system? How the synchronous checkpoints methods avoid the livelock problem? Discuss it.

5. Attempt any one part of the following: 7 x 1 = 7

(a) Define transaction management in distributed system. Explain the objectives of distributed transaction management.

(b) What do you mean by flat and nested distributed transactions? Differentiate it.

6. Attempt any one part of the following: 7 x 1 = 7

(a) Write short notes on:

     (i) Method to obtain consistent set of checkpoints:

     (ii) Domino effect.

(b) What is Replication? Discuss it using architectural model for replicated data.

7. Attempt any one part of the following: 7 x 1 = 7

(a) Discuss following:

     (i) Edge chasing algorithm.

     (ii) Path-Pushing algorithm.

(b) What do you understand by forward recovery and backward recovery. Describe advantages and disadvantages of forward recovery.

Thank You!