CKAD Application Observability and Maintenance Practice Question
Which probe type is used to determine if a container is ready to serve traffic?
⚠ Common exam trap
Many exam-takers confuse Liveness and Readiness probes, thinking both control traffic, but only the Readiness probe affects Service endpoints, while Liveness only triggers container restarts.
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
✓
Readiness probe
A Readiness probe determines whether a container is ready to accept traffic. If the probe fails, the container is removed from the Service's endpoints, ensuring no requests are routed to an unready pod. This is defined in the PodSpec under `readinessProbe` and is essential for rolling updates and traffic management.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Liveness probe
Why it's wrong here
A liveness probe determines whether the container is still running healthily; if it fails, the kubelet restarts the container according to the pod's restart policy. It does not affect Service endpoints, so a failing liveness probe does not remove the pod from network traffic, and the pod may still receive requests during crash loops.
- ✓
Readiness probe
Why this is correct
A readiness probe determines whether the container is ready to accept traffic; if it fails, the pod is removed from the endpoints of all Services. This directly controls traffic routing, making it the correct probe type to determine if a container is ready to receive requests. It does not restart the container, but only influences Service endpoint membership, allowing traffic to resume when the probe succeeds again.
- ✗
Startup probe
Why it's wrong here
A startup probe is designed for applications with slow startup times, running only once at initial launch; if it fails, the container is killed and restarted. While it affects the container lifecycle, it does not directly control traffic routing because readiness is managed separately, and a failing startup probe only delays readiness checks rather than removing the pod from Service endpoints.
- ✗
Resource probe
Why it's wrong here
There is no 'Resource probe' defined in the Kubernetes API. The available probe types are liveness, readiness, and startup, each of which can be implemented as an HTTP request, TCP check, or exec command. A 'Resource probe' would be a misconception, likely confusing health probes with resource requests and limits, which govern scheduling and allocation but have no effect on container health or traffic readiness.
Go deeper
Related to this question
About these practice questions
Courseiva writes every CKAD question from scratch — 826 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CKAD practice question is part of Courseiva's free CNCF 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 CKAD exam.