During a load test, the monitoring tool shows that the web server's memory utilization is at 95% and the paging file is actively used. The CPU is at 40%. The response time is increasing. Which metric from the monitoring tool would best confirm that memory pressure is causing the slowdown?

The network bytes received per second

The number of active TCP connections

The rate of page faults per second

A performance test engineer is investigating a spike in error responses during a load test. The load testing tool shows a 5% error rate, but the monitoring tool shows all servers are healthy. Which log-based metric would be most useful to pinpoint the cause of the errors?

The average size of log files on each server

The total number of log entries generated during the test

The timestamp of the first log entry in the test

The count of specific HTTP status codes (e.g., 500, 503) in the application logs

A test engineer is reviewing application logs after a load test. The logs show that a specific transaction took 5 seconds to complete, but the load testing tool reports an average response time of 2 seconds for the same transaction. Which log-based metric would best explain the discrepancy?

The timestamp of the slow transaction compared to the peak load period

The total number of log entries for the transaction

Which of the following metrics is typically provided by an infrastructure monitoring tool?

Business transaction success rate

Number of virtual users in a load test

How does a load testing tool typically generate the response time metric for a transaction?

By analyzing network packets captured on the wire

By measuring the elapsed time between sending the request and receiving the response

By reading the server's CPU utilization during the test

By querying the application's database for transaction logs

Certified Tester Performance Testing

Domain 2Objective 5

Key Sources of Performance Metrics CT-PT Practice Questions (Page 3)

Part of the Performance Measurement Fundamentals domain, which makes up ~28% of our current practice bank. ISTQB does not publish an official question count, but from its 90-minute exam (~35–60 total, ~10–17 in this domain), expect 2–3 from this objective — we provide 30 practice questions to prepare you well beyond it. (estimate)

30questions here

6free pages

6concepts

Questions 11–15

11application · medium
During a load test, the monitoring tool shows that the web server's memory utilization is at 95% and the paging file is actively used. The CPU is at 40%. The response time is increasing. Which metric from the monitoring tool would best confirm that memory pressure is causing the slowdown?
Select an answer first
12application · medium
A performance test engineer is investigating a spike in error responses during a load test. The load testing tool shows a 5% error rate, but the monitoring tool shows all servers are healthy. Which log-based metric would be most useful to pinpoint the cause of the errors?
Select an answer first
13application · medium
A test engineer is reviewing application logs after a load test. The logs show that a specific transaction took 5 seconds to complete, but the load testing tool reports an average response time of 2 seconds for the same transaction. Which log-based metric would best explain the discrepancy?
Select an answer first
14foundation · easy
Which of the following metrics is typically provided by an infrastructure monitoring tool?
Select an answer first
15foundation · easy
How does a load testing tool typically generate the response time metric for a transaction?
Select an answer first

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