Zero-downtime deployment pattern in Terraform - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Architecture

intermediate

Identify the key component for zero-downtime deployment

In a zero-downtime deployment pattern using Terraform, which component is essential to ensure new versions of an application are deployed without interrupting user access?

A A load balancer that shifts traffic gradually between old and new instances

B A single server that is updated in place with the new version

C A database migration script that runs after deployment

D A manual switch to turn off the old version before starting the new one

💡 Hint

Think about how traffic can be managed to avoid downtime during deployment.

A load balancer that shifts traffic gradually allows new instances to start serving requests before old ones stop, preventing downtime.

❓ Configuration

intermediate

Terraform resource for blue-green deployment

Which Terraform resource configuration best supports a blue-green deployment to achieve zero downtime?

A Two separate sets of instances with a shared load balancer switching between them

B A single autoscaling group with rolling update enabled

C One instance updated directly with the new version

D A database resource with version control enabled

💡 Hint

Blue-green deployment involves running two environments simultaneously.

Two separate instance groups allow switching traffic between old and new versions without downtime.

❓ service_behavior

advanced

Effect of deployment strategy on user requests

During a zero-downtime deployment using a canary release strategy, what happens to user requests?

A All user requests are immediately routed to the new version

B A small percentage of user requests are routed to the new version while the rest go to the old version

C User requests are queued until the deployment finishes

D User requests are dropped during the deployment

💡 Hint

Canary releases test new versions with a subset of users first.

Canary releases route a small portion of traffic to the new version to monitor stability before full rollout.

❓ security

advanced

Security consideration in zero-downtime deployments

What is a critical security consideration when implementing zero-downtime deployments with multiple active environments?

A Using the same database credentials for both environments without rotation

B Disabling all firewalls during deployment to avoid blocking traffic

C Allowing unrestricted SSH access to all instances during deployment

D Ensuring both old and new environments have consistent security group rules and access controls

💡 Hint

Think about how security policies apply when two environments run simultaneously.

Consistent security rules prevent vulnerabilities during traffic shift between environments.

✅ Best Practice

expert

Terraform state management in zero-downtime deployments

Which Terraform state management practice is best to support zero-downtime deployments in a team environment?

A Manually merge state files after each deployment

B Store state files locally on each developer's machine

C Use remote state storage with locking to prevent concurrent changes

D Disable state locking to speed up deployments

💡 Hint

Consider how to avoid conflicts when multiple people deploy infrastructure.

Remote state with locking ensures only one deployment modifies infrastructure at a time, preventing errors.