GRIFFITH COLLEGE DUBLIN
COMPUTING ASSIGNMENT TITLE SHEET
Course: BSCH Computing
Stage/Year: 4
Module: Distributed Systems
Semester: Semester I
Assignment Number: Assignment 2
Date of Title Issue: October 25th, 2023
Assignment Deadline: Two weeks after submission (see Moodle)
Assignment Submission: Moodle Upload
Assignment Weighting: 12.5%
Standard penalties will be applied to work that is submitted late, as per faculty guidelines.
All work must be your own
If you copy from someone else, both parties will be awarded a grade of 0.
Use of AI tools such as OpenAI or ChatGPT is strictly prohibited. Avoid the use of any online
resources excepting Stack Overflow. Do not share your code anywhere.
By submitting your assignment you accept that you understand what plagiarism is
and that your assignment is not plagiarised in any way.
Any cases of suspected plagiarism will be thoroughly investigated and may be brought in
for VIVA.
Learning Outcomes
Programme and related module learning outcomes that this assignment is assessing:
1,3
Assessment Criteria
Assessment criteria applied to this assignment, such as:
q Presentation
q Code Structure and Cleanliness
q Code Performance
q Appropriate Output
q Appropriate Method Selection
Assignment 2: Decode and Search
Ensure your code is well commented, as well as neat and readable. Code that fails
to compile will incur a penalty of 30%.
Work that is submitted late will incur standard penalties as per faculty guidelines.
For all programs you write: print your name and student number to the console
once, and include a comment at the top with your full name and student number.
You are given a template which includes several helper methods. Use this template
to complete the tasks for part 1.
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Part 1 – MPI Program 50%
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The provided a template .cpp file containing several helper methods:
createData(), decryptText(), searchText(), and exportText(). You do not need to
modify these methods, only invoke as needed. You are also provided your own
text file to be decoded and searched. Include this in the same directory as your
executable file.
Use the given template to create a distributed decryption MPI program to be run
using 4 nodes:
a) The given text file is encrypted with a traditional Caesar cipher using a
key from 1-25. The key to be used to decrypt the text file should be taken
from the user in console by Node0. The key should then be broadcast to
all other nodes.
Example: plaintext = ‘abcd’ key = 2 ciphertext = ‘cdef’
b) Node0 will read the txt file and store the data into an array by invoking
createData(). The array should then be partitioned into equal sized
chunks to be distributed among all nodes.
c) Each node will decrypt their given chunk using the key provided in
console using the decryptText() function stored into a new char array
called decipheredArray. After deciphering the text, each node will print its
deciphered array.
d) Each node will then invoke searchData() on its deciphered partial array to
find how many instances of the word “DISTRIBUTED” is contained in its
partition. After the function is called, each of the nodes will print its rank
and the amount of hits found.
e) Node 3 will collect each of the hits from the multiple nodes and add these
together. The result subsequently placed into a new variable, which will
be called totalhits. Node 2 will output this variable to console in the
format: “Distributed was found a total of
times.”
f) Each node will have a decrypted partial array of differing sizes. Use
strlen(partialArray) to store the length of each partial array. Node 0 will
collect all the partial decrypted text arrays from each of the nodes, store
into decryptedTotalArray and export as a text file by invoking the
exportText() function. Save the text file as DecryptedText.txt
Include in your submission.
Remember to close the MPI library and return control to the OS. Ensure your
code will work with a world size of 4.
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Part 2 – Documentation 40%
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You are to write a report relating to your code for part 1. This is a compulsory
part of your submission. Any submissions that do not include a report will
receive an automatic 0.
Use the provided template to complete your report. Answer each question in the
report, providing explanations, diagrams and screenshots as requested.
Remember to change the Name and StudentNumber at the top of the report, and
save as a PDF.
You will also be graded on the quality of your code. Ensure any code you submit
is robust, well commented, and well structured.
Always include a comment at the top of your code with your name and student
number, and output these to console once.
Submit your .cpp file (do not include header or makefiles) and pdf report
archived into a .zip file.
Tips:
Þ Keep your code simple: Coordinator() and Participant() not needed.
Þ Read the brief, then read it again. Then read the brief.
Þ Ensure your code is tidy and readable.
Þ Include appropriate comments.
Þ Make sure your code compiles and runs correctly.
o Anything not working, comment out and tell me why.
Þ Information that you output to console should be clear and concise.
o For example, your name/number should only be printed once
Þ Use the most appropriate MPI function for the task.
Þ Use the provided template and helper methods.