CTFL-v4 Testing Throughout the SDLC Practice Question
Exhibit
Error Log: [2023-10-12 14:20] ConnectionTimeoutException at UserAuthModule.java:45. Retrying... [2023-10-12 14:21] ConnectionTimeoutException at UserAuthModule.java:45. Retrying... [2023-10-12 14:22] CriticalFailure: AuthServer not reachable.
Refer to the exhibit. An automated test suite produces these logs. Which testing phase is most likely to catch this type of defect, and why?
⚠ Common exam trap
Candidates frequently select unit testing because timeouts involve specific code functions, ignoring that connection timeouts stem from communication between modules or external services.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Integration testing, because it validates module communication.
This log indicates a recurring connection timeout, which is a classic symptom of poor integration between the application and an external service. While unit tests might pass if they use mocks, integration testing is designed to verify the actual communication path. Catching this during integration testing ensures that environmental dependencies and real network configurations are validated before the system moves into the more complex system testing phase.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Component testing, because it verifies the code logic.
Why it's wrong here
Component testing typically uses stubs or mocks for external services. Therefore, it would likely pass even if the real service is down or slow, as it is not testing the actual network communication or the integration with the external authentication server environment.
- ✓
Integration testing, because it validates module communication.
Why this is correct
Integration testing is specifically designed to test the interfaces and connections between components. This log shows a failure in the communication layer between the application and the AuthServer, which is a textbook example of an issue that should be caught when verifying the system's integration points.
- ✗
Acceptance testing, because it tests business requirements.
Why it's wrong here
Acceptance testing is too late to catch a fundamental connectivity issue. By the time the software reaches acceptance testing, such a basic failure would have already been identified during earlier, lower-level testing phases, making it an inefficient place to discover this type of technical integration bug.
- ✗
Static testing, because it reviews the source code.
Why it's wrong here
Static testing focuses on the documentation and the code's text. While a code review might spot a hard-coded URL or a missing configuration parameter, it cannot verify the dynamic, runtime behavior of the network connection or the responsiveness of the remote authentication server under real conditions.
About these practice questions
This CTFL-v4 question is part of Courseiva's 144-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISTQB exam blueprint
This CTFL-v4 practice question is part of Courseiva's free ISTQB certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CTFL-v4 exam.