Canary deployment in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the main purpose of a canary deployment?

Imagine you have a new version of a microservice. You want to release it carefully to avoid breaking the whole system. What is the main goal of using a canary deployment?

A To test the new version with a small group of users before full release

B To release the new version to all users at once to save time

C To rollback the old version immediately after deployment

D To deploy the new version only in the development environment

💡 Hint

Think about reducing risk by limiting exposure.

Canary deployment releases the new version to a small subset of users first. This helps detect issues early before affecting everyone.

❓ Architecture

intermediate

Which component is essential for routing traffic in a canary deployment?

In a microservices system using canary deployment, which component is responsible for directing a portion of user requests to the new version while the rest go to the stable version?

A Logging and monitoring tool

B Database replication service

C Continuous integration server

D Load balancer with traffic splitting capability

💡 Hint

Think about how requests are distributed.

A load balancer that supports traffic splitting can route some requests to the new version and others to the stable version, enabling canary deployment.

❓ scaling

advanced

How should you scale the canary version during deployment?

You start a canary deployment by sending 5% of traffic to the new version. Over time, you want to increase this percentage. What is the best practice for scaling the canary version?

A Randomly change traffic percentages without monitoring

B Gradually increase traffic to the canary version while monitoring metrics

C Keep the canary version at 5% traffic indefinitely

D Immediately switch 100% traffic to the new version after deployment

💡 Hint

Think about risk and feedback.

Gradually increasing traffic allows detecting problems early and reduces risk. Monitoring metrics ensures stability before full rollout.

❓ tradeoff

advanced

What is a tradeoff when using canary deployment compared to blue-green deployment?

Canary and blue-green deployments are both strategies to release new versions. What is a key tradeoff when choosing canary deployment over blue-green?

A Canary deployment exposes only a small user group to risk but takes longer to fully release

B Canary deployment instantly switches all users to the new version

C Canary deployment requires more infrastructure than blue-green

D Canary deployment does not allow rollback

💡 Hint

Consider risk exposure and release speed.

Canary deployment reduces risk by exposing a small group first but takes more time to complete rollout compared to blue-green which switches all users at once.

❓ estimation

expert

Estimate the number of users affected during a canary deployment with 10 million daily users and 1% canary traffic

Your service has 10 million daily active users. You deploy a new version using canary deployment, routing 1% of traffic to it. How many users will experience the new version daily?

A 500,000 users

B 10,000 users

C 100,000 users

D 1,000,000 users

💡 Hint

Calculate 1% of 10 million.

1% of 10 million is 100,000 users who will see the canary version daily.