DOL CI/CD Pipeline 3

Question 1

A deployment pipeline passes all automated tests but the production release still causes user-facing errors. Which practice would most likely have caught this gap?

Accepted Answer

Implementing synthetic monitoring and real-user monitoring (RUM) post-deployment

Answer

Synthetic monitoring simulates user journeys in production while RUM captures real user experience, surfacing issues automated pre-deployment tests cannot replicate.

Question 2

What distinguishes a 'blue-green deployment' from a 'rolling deployment'?

Accepted Answer

Blue-green switches all traffic instantly between two identical environments; rolling updates instances incrementally

Answer

Blue-green maintains two full environments and flips the load balancer, enabling instant cutover and rollback, while rolling gradually replaces instances.

Question 3

A team uses Docker images as pipeline artifacts. What is the best practice for ensuring image immutability across environments?

Accepted Answer

Build once, tag with the commit SHA, and promote the same image across all environments

Answer

Building once and promoting the same immutable image tagged by commit SHA ensures what was tested is exactly what gets deployed to production.

Question 4

Which CI/CD pattern ensures that a deployment does not proceed if monitoring dashboards show elevated error rates after an initial traffic shift?

Accepted Answer

Progressive delivery with automated rollback triggers based on observability signals

Answer

Progressive delivery couples traffic shifting with automated health checks so pipelines can self-heal by rolling back when error thresholds are breached.

Question 5

When implementing database migrations in a CI/CD pipeline, what approach prevents downtime during schema changes?

Accepted Answer

Apply forward-only, backward-compatible migrations so old and new code run simultaneously

Answer

Backward-compatible migrations allow the old application version to keep running while the new version is deployed, enabling zero-downtime releases.

(DOL) DevOps Leader Practice Test

(DOL) DevOps Leader Practice Test

DOL CI/CD Pipeline 3