Assignment 2: Time

1. Why does clock synchronization important in distributed system?

2. Can there exist some distributed system which does not require clock synchronization? If yes, give an example, and if no, explain why not?

3. What do you mean by global clock?

4. Define happened before relation using the formal notation for Lamport clock.

5. When do you say two events are concurrent for lamport clock? How about four events?

6. What is total ordering and partial ordering of events in the context of Lamport clock. Which one is achieved using Lamport clock? Why?

7. Understand the notations of vector time and their relationhips. Define when t1>= t2, etc.

8. Understand the weaknesses of Lamport and Vector clocks.

9. Understand the weaknesses of Lamport and Vector clocks.

10. What is the notion of causality?

11. Do a comparative report on external and internal synchronization.

12. Why computer clocks differ? Define clock drift and explain the bound on resynchronization time.

13. How to handle fast and slow clocks during clock synchronization?

14. Do a comparative study/report on Christian and Berkeley algorithms.

15. Write a report on Real time, UTC and GPS. Do a comparative report on Atomic time and Astronimical time.

16. Explain how NTP works.

17. What kind of gurantees can NTP give?

18. What are the advantages of logical clock over physical clock.