Description
- (5 points) What is view synchronous? What is atomic message?
- (5 points) What is coordinated checkpointing?
- (10 points) What is a Byzantine failure? How many replicas are needed to survive a k component fail in Byzantine failure? Why?
- (10 points) Consider a Web browser that returns an outdated cached page instead of more recent one that had been updated at the server. Is this a failure, and if so, what kind of failure?
- (10 points) We have stated that totally ordered multicasting using Lamport’s logical clocks does not scale. Explain why.
- (10 points) In reliable multicasting, is it always necessary that the communication layer keeps a copy of a message for retransmission purposes?
- (10 points) In the two-phase commit protocol, why can blocking never be eliminated, even when the participants elect a new coordinator?
