Operating System Multiple Choice Questions on “Distributed Coordination”.
1. What are the characteristics of tightly coupled system?
i) Same clock, usually shared memory
ii) Communication is via this shared memory
iii) Multiprocessors
iv) Different clock
a) i
b) i, ii and ii
c) ii and iii
d) i, iii and iv
Answer: b
2. What are the characteristics of tightly coupled system?
i) Different clock
ii) Use communication links
iii) Same clock
iv) Distributed systems
a) i
b) i and iv
c) i, ii and iii
d) ii, iii and iv
Answer: d
3. What are the characteristics of mutual exclusion using centralized approach?
a) One processor as coordinator which handles all requests
b) It requires request,reply and release per critical section entry
c) The method is free from starvation
d) All of the mentioned
Answer: d
4. What are the characteristics of fully distributed approach?
i) When responses are received from all processes, then process can enter its Critical Section
ii) When process exits its critical section, the process sends reply messages to all its deferred requests.
iii) It requires request,reply and release per critical section entry
iv) One processor as coordinator which handles all requests
a) i
b) i and ii
c) ii and iii
d) iii and iv
Answer: b
5. What are the advantages of token(with rings) passing approach?
i) One processor as coordinator which handles all requests
ii) No starvation if the ring is unidirectional
iii) There are many messages passed per section entered if few users want to get in section
iv) One processor as coordinator which handles all requests
v) Only one message/entry if everyone wants to get in
a) i
b) ii and iii
c) i, ii and iii
d) i, ii and iv
Answer: d
6. What are the characteristics of atomicity?
a) All operations associated are executed to completion or none are performed
b) One processor as coordinator which handles all requests
c) When responses are received from all processes, then the process can enter its Critical Section
d) Use communication links
Answer: a
7. What things are the transaction coordinator is responsible for?
a) Starting the execution of the transaction
b) Breaking transaction into a number of subtransactions
c) Coordinating the termination of the transaction
d) All of the mentioned
Answer: d
8. Which of the following advantages follows the single coordinator approach?
a) Simple implementation
b) Simple deadlock handling
c) bottleneck
d) All of the mentioned
Answer: d
9. Which of the following disadvantages follows the single coordinator approach?
a) Bottleneck
b) Slow response
c) Deadlock
d) One request per second
Answer: a
10. What are the disadvantages of majority protocol?
a) Complicated implementation
b) Deadlock cannot occur easily
c) Bottleneck
d) All of the mentioned
Answer: a
11. What are the parts of a global unique identifier?
a) Local unique timestamp
b) Remote timestamp
c) Clock number
d) All of the mentioned
Answer: a
12. Which are the two complementary deadlock-prevention schemes using timestamps?
a) The wait-die & wound-wait scheme
b) The wait-n-watch scheme
c) The wound-wait scheme
d) The wait-wound & wound-wait scheme
Answer: a