High availability configuration in GCP - Mini Project: Build & Apply

High availability configuration

📖 Scenario: You are setting up a simple web application on Google Cloud Platform (GCP). To ensure your application is always available, even if one server fails, you want to configure a high availability setup.This means your app will run on multiple virtual machines, and traffic will be balanced between them automatically.

🎯 Goal: Build a high availability configuration on GCP by creating an instance template, a managed instance group with multiple instances, and a load balancer to distribute traffic.

📋 What You'll Learn

Create an instance template named web-instance-template with a Debian image

Create a managed instance group named web-mig in the us-central1-a zone using the instance template with 2 instances

Create a HTTP load balancer forwarding rule named web-lb that balances traffic to the managed instance group

💡 Why This Matters

🌍 Real World

High availability ensures that web applications stay online even if some servers fail. This setup is common for websites and services that need to be reliable.

💼 Career

Cloud engineers and DevOps professionals often configure managed instance groups and load balancers to build scalable and fault-tolerant applications.

1

Create an instance template

Create an instance template called web-instance-template using the Debian 11 image from the debian-cloud project.

GCP

# Your code here to create the instance template named web-instance-template

Need a hint?

Use gcloud compute instance-templates create with --image-family=debian-11 and --image-project=debian-cloud.

2

Create a managed instance group

Create a managed instance group named web-mig in zone us-central1-a using the instance template web-instance-template with 2 instances.

GCP

gcloud compute instance-templates create web-instance-template \
  --image-family=debian-11 \
  --image-project=debian-cloud
# Your code here to create the managed instance group named web-mig

Need a hint?

Use gcloud compute instance-groups managed create with --size 2, --template web-instance-template, and --zone us-central1-a.

3

Create a backend service and health check

Create a health check named web-health-check and a backend service named web-backend-service that uses the health check and points to the managed instance group web-mig in zone us-central1-a.

GCP

gcloud compute instance-templates create web-instance-template \
  --image-family=debian-11 \
  --image-project=debian-cloud

gcloud compute instance-groups managed create web-mig \
  --base-instance-name web-instance \
  --size 2 \
  --template web-instance-template \
  --zone us-central1-a
# Your code here to create health check and backend service

Need a hint?

Create a health check with gcloud compute health-checks create http web-health-check --port 80. Then create a backend service with gcloud compute backend-services create web-backend-service --protocol HTTP --health-checks web-health-check --global. Finally, add the instance group as backend with gcloud compute backend-services add-backend.

4

Create a HTTP load balancer forwarding rule

Create a URL map named web-url-map, a target HTTP proxy named web-http-proxy, and a global forwarding rule named web-lb that listens on port 80 and forwards traffic to the backend service web-backend-service.

GCP

gcloud compute instance-templates create web-instance-template \
  --image-family=debian-11 \
  --image-project=debian-cloud

gcloud compute instance-groups managed create web-mig \
  --base-instance-name web-instance \
  --size 2 \
  --template web-instance-template \
  --zone us-central1-a

gcloud compute health-checks create http web-health-check --port 80

gcloud compute backend-services create web-backend-service --protocol HTTP --health-checks web-health-check --global

gcloud compute backend-services add-backend web-backend-service --instance-group web-mig --instance-group-zone us-central1-a --global
# Your code here to create the URL map, target proxy, and forwarding rule named web-lb

Need a hint?

Create URL map: gcloud compute url-maps create web-url-map --default-service web-backend-service --global
Create target proxy: gcloud compute target-http-proxies create web-http-proxy --url-map web-url-map --global
Create forwarding rule: gcloud compute forwarding-rules create web-lb --global --ports=80 --target-http-proxy web-http-proxy.