Software Engineering Multiple Choice Questions on “Fault Tolerance”.
1. What type of fault remains in the system for some period and then disappears?
a) Permanent
b) Transient
c) Intermittent
d) All of the mentioned
Answer: b
Clarification: For example many faults in communication systems are transient in nature.
2. Which of the following approaches are used to achieve reliable systems?
a) Fault prevention
b) Fault removal
c) Fault tolerance
d) All of the mentioned
Answer: d
Clarification: All the options lead to formation of a reliable system.
3. A system maintaining its integrity while accepting a temporary halt in its operation is said to be in a state of
a) Full Fault Tolerance
b) Graceful Degradation
c) Fail Soft
d) Fail Safe
Answer: d
Clarification: None.
4. Which of the following Error Detection checks is not a part of Application detection?
a) Hardware checks
b) Timing checks
c) Reversal checks
d) Coding checks
Answer: a
Clarification: Hardware is a part of environment detection check.
5. Exception handling is a type of
a) forward error recovery mechanism
b) backward error recovery mechanism
c) All of the mentioned
d) None of the mentioned
Answer: a
Clarification: Exception handling is a forward error recovery mechanism, as there is no roll back to a previous state; instead control is passed to the handler so that recovery procedures can be initiated.
6. Non-occurrence of improper alteration of information is known as
a) Available Dependability
b) Confidential Dependability
c) Maintainable Dependability
d) Integral Dependability
Answer: d
Clarification: Integrity is to keep the original content safe from alteration.
7. In N-version programming which is the independent generation of N, the value of N is
a) greater than 1
b) less than 1
c) greater than 2
d) less than 2
Answer: c
Clarification: N-version programming (NVP), also known as multiversion programming or multiple-version dissimilar software, is a method or process in software engineering where multiple functionally equivalent programs are independently generated from the same initial specifications.
8. In Log-based fault tolerance, logs of undetermined events are saved and replayed on failure.
a) True
b) False
Answer: a
Clarification: None.
9. All fault-tolerant techniques rely on
a) Integrity
b) Dependability
c) Redundancy
d) None of the mentioned
Answer: c
Clarification: All fault-tolerant techniques rely on extra elements introduced into the system to detect & recover from faults.
10. It is imperative for a communicating processes to reach consistent recovery points to avoid the _________ effect, with backward error recovery mechanism.
a) Static
b) Dynamic
c) Domino
d) Whirlpool
Answer: c