CSI Performance Benchmarking & Tuning 3

Question 1

What does the acronym 'IOPS' measure in storage performance benchmarking?

Accepted Answer

Input/Output operations per second

Answer

IOPS measures how many read or write operations a storage device can perform per second, a key metric for evaluating storage performance.

Question 2

During a stress test, which condition signals that a system has reached its 'breaking point'?

Accepted Answer

Error rate rises sharply and throughput drops simultaneously

Answer

The breaking point is characterized by both a spike in errors and a drop in throughput, indicating the system can no longer handle additional load.

Question 3

Which HTTP keep-alive setting tuning reduces connection overhead in a high-request-rate web application?

Accepted Answer

Increasing the keep-alive timeout and maximum requests per connection

Answer

Increasing keep-alive timeout and max requests per connection allows more requests to reuse established TCP connections, reducing handshake overhead.

Question 4

A system integrator notices that adding more threads beyond a certain count actually decreases throughput. Which principle explains this?

Accepted Answer

Amdahl's Law and thread contention overhead

Answer

Amdahl's Law predicts diminishing returns from parallelism, and excessive threads introduce contention overhead that outweighs the parallelism benefit.

Question 5

What is the main advantage of using percentile-based SLAs (e.g., p99) over average-based SLAs for latency targets?

Accepted Answer

Percentiles capture tail latency experienced by the worst-affected users

Answer

Average latency can mask severe slowdowns for a subset of users, while percentile-based SLAs ensure that even the worst-case users receive acceptable service.

(CSI) Certified System Integrator Practice Test

(CSI) Certified System Integrator Practice Test

CSI Performance Benchmarking & Tuning 3