DevOps DevOps 3 — Questions and Answers
Question 1: What is the purpose of a 'blue-green deployment'?
- Maintaining two identical environments to switch traffic with zero downtime (Correct answer)
- Color-coding logs by severity
- Running blue tests before green tests
- Separating frontend and backend teams
Correct answer: Maintaining two identical environments to switch traffic with zero downtime
Blue-green deployment keeps two production environments so traffic can switch instantly with minimal downtime.
Question 2: In Docker, what is the difference between an image and a container?
- An image is a static template; a container is a running instance of it (Correct answer)
- An image runs while a container is stored on disk
- They are identical terms
- A container builds images automatically
Correct answer: An image is a static template; a container is a running instance of it
An image is the immutable blueprint, and a container is a live running instance created from it.
Question 3: Which metric is part of the DORA 'Four Key Metrics' for DevOps performance?
- Deployment frequency (Correct answer)
- Number of open browser tabs
- Lines of code per commit
- Total Slack messages sent
Correct answer: Deployment frequency
Deployment frequency is one of the four DORA metrics measuring software delivery performance.
Question 4: What does 'observability' primarily rely on?
- Logs, metrics, and traces (Correct answer)
- Only CPU usage graphs
- Manual code reviews
- User satisfaction surveys
Correct answer: Logs, metrics, and traces
Observability is built on the three pillars of logs, metrics, and traces to understand system internal state.
Question 5: In a pipeline, what is a 'gate' or 'approval step' used for?
- Requiring a condition or human sign-off before promoting to the next stage (Correct answer)
- Increasing build speed automatically
- Caching dependencies
- Deleting old artifacts
Correct answer: Requiring a condition or human sign-off before promoting to the next stage
A gate pauses the pipeline until a condition is met or approval is granted before continuing.
Question 6: What problem does a 'service mesh' (e.g., Istio) primarily solve?
- Managing service-to-service communication, security, and observability (Correct answer)
- Compiling source code faster
- Storing container images
- Provisioning bare-metal servers
Correct answer: Managing service-to-service communication, security, and observability
A service mesh handles inter-service traffic management, security, and observability transparently.
Question 7: Why is 'secrets management' (e.g., HashiCorp Vault) important in DevOps?
- To securely store and rotate credentials instead of hardcoding them (Correct answer)
- To speed up the CI pipeline
- To compress build artifacts
- To document API endpoints
Correct answer: To securely store and rotate credentials instead of hardcoding them
Secrets management securely stores, controls access to, and rotates sensitive credentials outside of code.
DevOps DevOps 3
What is the purpose of a 'blue-green deployment'?