Consider a popular sports news site. At a given moment, 20,000 concurrent…
2023
Consider a popular sports news site. At a given moment, 20,000 concurrent users submit a request (a transaction, T) once every 2 minutes on average. Each transaction requires the web app to download a new article that on average has 3 k bytes in length.
What is the throughput?
- A.
8 megabits per second
- B.
4 megabits per second
- C.
6 megabits per second
- D.
2 megabits per second
Attempted by 25 students.
Show answer & explanation
Correct answer: B
Given:
Concurrent users = 20,000
Each user submits 1 request every 2 minutes
Size of each transaction = 3 kB
Step 1: Requests per second
Each user → 1 request / 2 minutes
2 minutes = 120 seconds
Total requests per second:
20000120=166.67 requests/sec\frac{20000}{120} = 166.67 \text{ requests/sec}12020000=166.67 requests/sec
Step 2: Data per second
Each request = 3 kB
Total data:
166.67×3 kB=500 kB/sec166.67 \times 3 \text{ kB} = 500 \text{ kB/sec}166.67×3 kB=500 kB/sec
Step 3: Convert to megabits per second
500 kB/sec = 0.5 MB/sec
1 byte = 8 bits
0.5×8=4 megabits/sec0.5 \times 8 = 4 \text{ megabits/sec}0.5×8=4 megabits/sec
Correct Answer → B. 4 megabits per second
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