chapter 8

Question 1

failure

Answer 1

the system is said to “fail” when it can not meet its promises.

Question 2

fault tolerante

Answer 2

a system can provides its services even in the presence of faults.

Question 3

fault types

Answer 3

1. transient fault
2. intermittent fault
3. permanent fault

Question 4

What does the dependency implies ?

Answer 4

1. Availability
2. Reliability
3. Safety
4. Maintainability

Question 5

Crash failure

Answer 5

A server halt, but is working correctly until it halts

Question 6

omission failure

Answer 6

a server fails to respond to incoming requests

Question 7

receive omission

Answer 7

a server fails to receive incoming message

Question 8

send omission

Answer 8

a server fails to send messages

Question 9

timing failure

Answer 9

a server’s response lies outside the specified time interval.

Question 10

response failure

Answer 10

a server’s response is incorrect.

Question 11

value failure

Answer 11

the value of the response is wrong.

Question 12

arbitrary failure

Answer 12

a server may produce arbitrary responses at arbitrary times.

Question 13

forward error recovery

Answer 13

find a new state from which the system can continue operation.

Question 14

RPC communication: Solutions

Answer 14

1:Relatively simple – just report back to client 2:Just resend message

Question 15

backward error recovery

Answer 15

bring the system back into a previous error free state.