The Assignment-1 Specification and Marking Criteria
Distributed Hash Table (DHT) is a new distributed computing paradigm that harnesses the computing and storage resources across the Internet for providing a variety of services such as distributed file systems, content-distribution systems, and domain name services etc. Among others, Chord (http://pdos.csail.mit.edu/papers/chord:sigcomm01/chord_sigcomm.pdf) is an original and successful DHT protocol, and Open Chord (http://open-chord.sourceforge.net/ ) is an open source implementation of Chord protocol.
In this assignment, you are to research DHT and write a technical report about DHT. The report is to be structured as an academic report and the sections must be titled and numbered. Your work must be appropriately referenced using the Harvard (author-date) referencing style. The length of the report should be about 2,500 words. You are not required to provide an Executive Summary for the report. An Exemplar for Writing a Simple Academic Technical Report is available on the unit web site; you should read it before writing your report.
To prepare your report, you will need to research widely on DHT, and download and use Open Chord. Your report must cover the issues that are detailed as follows.
Part 1: General Review of DHT
1. What is distributed hash table (DHT)?
2. How is the hash function performed in DHT?
3. What distributed services can be built on DHT?
Part 2: Review of Chord
1. What is the topology of Chord DHT?
2. What is the consistent hashing of Chord?
3. Chord search algorithm and performance
4. Chord node joins and stabilisation
5. Chord node failure
Part 3: Demonstration of DHT features via Open Chord
In this part you need to demonstrate some features of DHT and Chord by Open Chord software. You need to download Open Chord and read its Unser’s Manual. You don’t have to rebuild (compile) the source code as these features can be demonstrated through the Open Chord Console (as detailed in Section 4 of the User’s Manual). To complete this part you need use both screenshots and textual explanations.
1. Creation of a Chord overlay on a single JVM
Crate an Open Chord overlay network which has at least 8 nodes running on single Java Virtual Machine (JVM). Show the screenshots with the commands to create the overlay.
2. Insert into and retrieve values from the Chord DHT
Show a screenshot that inserts a pair of (key, value) from a node. Check how the value is replicated by showing the DHT entries at each node by screenshots. Show a screenshot to retrieve the value from a node.
3. Show the finger table, predecessors and successors of a node
4. Node leave and stabilisation
Make a node that stores the value leave and check how the value is replicated through the Chord stabilisation algorithm.
5. Node Failure and stabilisation
Crash a node that stores the value and check how the value is replicated. What is the default number of replicates that Open Chord maintains for a key-value pair?
The assignment must be submitted as a single Microsoft Word document. You must submit your assignment via the unit web site. Any hardcopy or email submission will not be accepted. After the marked assignments are returned, any late submissions will not be accepted.
Criteria Available Marks
1. Introduce your research of DHT and its role in distributed systems 0.5
2. What are you going to cover in the remainder of the report? 0.5
Part 1: General Review of DHT 3.0
1. What is distributed hash table (DHT) 1.0
2. How is the hash function performed in DHT 1.0
3. What distributed services can be built on DHT 1.0
Part 2: Review of Chord 10.0
1. What is the topology of Chord DHT 2.0
2. What is the consistent hashing of Chord 2.0
3. Chord search algorithm and performance 2.0
4. Chord node joins and stabilisation 2.0
5. Chord node failure 2.0
Part 3: Demonstration of DHT features via Open Chord 5.0
1. Creation of a Chord overlay on a single JVM 1.0
2. Insert into and retrieve values from the Chord DHT 1.0
3. Show the finger table, predecessors and successors of a node 1.0
4. Node leave and stabilisation 1.0
5. Node Failure and stabilisation 1.0
What does your research conclude about DHT in general
and Chord DHT protocol
Sub Total for Assignment-1 20.0
Late Penalty -1 (5% each calendar day)
Total for Assignment-1