代做Enterprise-Scale Software Development (COMP5348) Semester 2, 2024 Assignment 2调试SPSS

COMP4348/5348 A2

Enterprise-Scale Software Development (COMP5348)

Semester 2, 2024

Assignment 2

Individual 10%

Due: 20 Oct 2024 at 23:59 on Canvas.

There are 3 questions, each worth 3 points, 4 points and 3 points respectively. For the calculation questions, you need to show your progress. Just giving the final result is not acceptable.

You can write your answers on paper and scan, or you can type your answers in your computer. Please merge all you answers in a single pdf file and upload in Canvas.

Question 1 (3 points)

In a REST-based design for a service, all the functionalities are provided through the limited set of HTTP verbs (GET, PUT, POST, DELETE, HEAD, OPTIONS).

Propose a RESTful design for the resources, URIs and operations, for a system that manages assignment attempt submission, as well as marking of attempts for students in courses. Your design should be RESTful, but would correspond to traditional design around methods like submitAttempt, fetchAssignmentAttempts, markAttempt, fetchUnmarkedAssignmentAttempts, fetchStudentUnattemptedAssignments, etc.

Question 2 (4 points)

Consider a database system that serves transactions of 2 distinct kinds. Each query transaction requires 35 ms of CPU processing and reading 230 blocks from disk (where each block occupies 4KB, and the disk can deliver 100 MB/s). Each update transaction requires 0.3ms of CPU processing, reading 1 block from disk, and it also requires sending a log record to a dedicated archival storage, an operation which occupies this resource for 30 ms. Each client generates transactions without any think time between one response and the next request.

(a) Suppose that each client generates requests for which the transaction mix consists of 25% update transactions and 75% query transactions. If there are 3 clients, use the “low-load bounds” to estimate the throughput and latency obtained.

(b) Still with 25% update transactions, what is the largest number of clients for which average response time will be below 2s?

Question 3 (3 points)

Consider a system WebSys made from 3 components:

   • Component A has MTTF of 3 months and MTTR of 2 days

   • Component B has MTTF of 1 yr and MTTR of 4 days

   • Component C has MTTF of 1 month and MTTR of 6 days

Calculate the overall availability and MTTF and MTTR, for the whole system WebSys.