Canary deployments in Nginx - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Canary deployment traffic split with NGINX

Given this NGINX configuration snippet for canary deployment, what percentage of traffic is routed to the canary backend?

Nginx

upstream backend {
    server backend-v1.example.com weight=1;
    server backend-v2.example.com weight=1;
}

server {
    listen 80;
    location / {
        proxy_pass http://backend;
    }
}

A 10%

B 25%

C 50%

D 0%

💡 Hint

Weights in upstream servers determine traffic distribution proportionally.

The upstream block has two servers: backend-v1 with weight 1 and backend-v2 with weight 1. Traffic is split evenly 50% each.

❓ Configuration

intermediate

Configure NGINX for 10% canary traffic

Which NGINX upstream configuration correctly routes 10% of traffic to the canary backend and 90% to the stable backend?

A

upstream backend {
    server stable.example.com weight=9;
    server canary.example.com weight=1;
}

B

upstream backend {
    server stable.example.com weight=10;
    server canary.example.com weight=1;
}

C

upstream backend {
    server stable.example.com;
    server canary.example.com weight=0.1;
}

D

upstream backend {
    server stable.example.com weight=1;
    server canary.example.com weight=9;
}

💡 Hint

Weights are relative and must be integers.

Weights define relative traffic. Weight 9 + 1 means 90% to stable, 10% to canary.

❓ Troubleshoot

advanced

Why is canary traffic not reaching the canary backend?

You configured NGINX with a canary backend using weights, but all traffic goes to the stable backend. What is the most likely cause?

A The canary backend server is down or unreachable.

B The stable backend has a lower weight than the canary backend.

C NGINX does not support weighted upstreams.

D The proxy_pass directive is missing in the location block.

💡 Hint

Check backend server health and connectivity.

If the canary backend is down, NGINX routes all traffic to the healthy stable backend regardless of weights.

🔀 Workflow

advanced

Steps to implement a canary deployment with NGINX

What is the correct order of steps to perform a canary deployment using NGINX?

A 2,3,1,4

B 2,1,3,4

C 1,3,2,4

D 1,2,3,4

💡 Hint

Think about deploying first, then routing traffic, then monitoring, then scaling.

First deploy canary, then route traffic, monitor results, and finally increase traffic or promote.

✅ Best Practice

expert

Best practice for canary deployment rollback with NGINX

If the canary deployment shows errors, what is the safest way to rollback using NGINX configuration?

A Stop the canary backend server without changing NGINX configuration.

B Remove the canary backend from the upstream block and reload NGINX.

C Set the canary backend weight to zero and reload NGINX.

D Increase the stable backend weight and reload NGINX.

💡 Hint

Rollback means no traffic should go to canary backend.

Removing the canary backend from upstream ensures no traffic is routed there. Setting weight to zero is invalid in NGINX.