Performance

Question 1

True/False: Performance is a functional requirement

Answer 1

False. Performance is a non-functional requirement

Question 2

How can performance be measured?

Answer 2

• Concurrency (# of requests/users at once)
• Latency (ms)
• Volume (requests/second)
• Bandwidth (bytes/second)
• Utilization (percent)

Question 3

When should one optimize their code?

Answer 3

When performance issues arise

Question 4

How can one check if changes made lead to performance issues?

Answer 4

1. Measure performance indicators before making changes
2. Record numbers for each indicator
3. Record numbers after changes are made
4. Run tests more than once

Question 5

What techniques can be used to improve performance?

Answer 5

• Caching
• Reduce # of round trips
• Reduce download size
• Asynchronous communication

Question 6

How does caching improve performance?

Answer 6

Caching increases locality (content/data is closer to where it is needed). Locality increases available bandwidth and decreases latency.