CS542 Homework 5

Due: 04/25/06

  Feel free to use slides on Raidlab (CS 145) table.

Question 1:   How can we measure the delays and round trip times between multiple sites and how can we improve them?

Question 2: How would you change the design and algorithms for distributed database processing if the communication delay was three time higher than normal?

Question 3: How would you change the design and algorithms for distributed database processing if the communication delay was almost zero?

Question 4: How would you change the design and algorithms for distributed database processing if there were multiple and frequent failures (like sites failing and recovering, network partitions, variable communication delays, large number of lost messages)?

Question 5: Consider applications such as Digital Libraries, Electronic Commerce, Video Conferencing.
a) What type of communication behavior (in terms of round trip times, reliability) that is required in such applications?
b)  How can we deal with the bandwidth and network capacity to realize such applications and make them successful?
c)  What will be the performance evaluation criterion for such systems?

Question 6: How do privacy issues affect distributed transaction processing? What schemes can be used to ensure privacy of database access?