CSCI319 Assignment 2

Similar to Assignment 1, The assignment 2 consists of 13 short questions in my year of study. It is 15% of the total mark and again, it is the test of your understanding in the subject. I will list the questions below.

1. Give at least four examples of true identifiers?
2. Distributed hash table (book chapter 5.2.3) provide means to resolve an identifier to the address of the associated entity. Consider the Chord System as shown in Fig. 5-4 and assume that node 7 has just joined the network. What would its finger table be and would there be any changes to other finger table. (You need to copy the page for chapter 5.2.3 Fig 5-4)
3. What is a major drawback of recursive lookups when resolving a key in DHT-based system?
4. Explain the difference between a hard link and a soft link in Unix systems. What things that can be done with a hard link that cannot be done with a soft link or vice versa?
5. Suppose that two processes detect the demise of the coordinator simultaneously and both decide to hold an election using the bully algorithm. What happens?
6. In Fig 7-7, is 001110 a legal output for a sequentially consistent memory? (You need the figure 7-7 from book)
7. Consider a non-blocking primary-backup protocol used to guarantee sequential consistency in a distributed data store. Does such a data store always provide read-your-write consistency? Explain.
8. To implement totally ordered multicasting by means of a sequencer, one approach is to first forward an operation to the sequencer, which then assign it to unique number and subsequently multicasts the operation. Mention two alternative approaches and compare the three solutions.
9. A file is replicated on 10 servers. List all the combinations of read quorum and write quorum that are permitted by the voting algorithm.
10. How many failed elements (devices plus voters) can figure 8-2 handle? Give an example of the worst case that can be masked. (You need the figure 8-2 from book)
11. In the case of reliable FIFO-ordered multicasts, the communication layer is forced to deliver incoming messages from the same process in the same order as they have been sent. What are the permissible delivery orderings for the combination of FIFO and total-ordered multicasting in Fig 8-15. (You need the figure 8-15 from book)
12. In the two-phase commit protocol (chapter 8.5.1 in the book), why can blocking never be completely eliminated, even when the participants elect a new coordinator?
13. Receiver-based message logging is generally considered better than sender-based logging. Why?

Well, this questions are able to find by Google Search in the Internet. You will need to purchase the book called "Distributed Systems, Principles and Paradigms, by Andrew S.Tanenbaum and Maarten Van Steen". I have the ebook copy, but not latest version. I will upload it another post.