Cloud Load Balancing is a fully distributed, software-defined managed service for all your traffic. It provides load balancing for HTTP(S), TCP/SSL, and UDP traffic, and it can be used to distribute traffic across multiple backend instances, regions, and even hybrid environments.

1. Load Balancer Types:

   • HTTP(S) Load Balancing: Distributes HTTP and HTTPS traffic.
   • TCP/SSL Proxy Load Balancing: Distributes TCP and SSL traffic.
   • UDP Load Balancing: Distributes UDP traffic.

2. Backend Services:

   • Instance Groups: Collections of VM instances that serve as the backend for the load balancer.
   • Backend Buckets: Cloud Storage buckets that serve static content.

3. Health Checks:

   • Regularly check the health of backend instances to ensure traffic is only sent to healthy instances.

4. URL Maps:

   • Define how incoming requests are routed to backend services based on URL patterns.

5. SSL Certificates:

   • Secure your load balancer with SSL certificates for HTTPS traffic.

1. Create a Health Check:

   gcloud compute health-checks create http my-health-check 
           --port 80 
           --request-path /
   

2. Create a Managed Instance Group:

   gcloud compute instance-templates create my-template 
           --machine-type n1-standard-1 
           --image-family debian-9 
           --image-project debian-cloud 
           --metadata startup-script='#! /bin/bash
       sudo apt-get update
       sudo apt-get install -y apache2
       sudo service apache2 restart'
   

   gcloud compute instance-groups managed create my-instance-group 
           --base-instance-name my-instance 
           --template my-template 
           --size 2 
           --zone us-central1-a
   

3. Create a Backend Service:

   gcloud compute backend-services create my-backend-service 
           --protocol HTTP 
           --port-name http 
           --health-checks my-health-check 
           --global
   

4. Add the Instance Group to the Backend Service:

   gcloud compute backend-services add-backend my-backend-service 
           --instance-group my-instance-group 
           --instance-group-zone us-central1-a 
           --global
   

5. Create a URL Map:

   gcloud compute url-maps create my-url-map 
           --default-service my-backend-service
   

6. Create a Target HTTP Proxy:

   gcloud compute target-http-proxies create my-http-proxy 
           --url-map my-url-map
   

7. Create a Global Forwarding Rule:

   gcloud compute forwarding-rules create my-http-rule 
           --global 
           --target-http-proxy my-http-proxy 
           --ports 80
   

1. Create an SSL Certificate:

   gcloud compute ssl-certificates create my-ssl-cert 
           --certificate /path/to/cert.pem 
           --private-key /path/to/key.pem
   

2. Create a Target HTTPS Proxy:

   gcloud compute target-https-proxies create my-https-proxy 
           --url-map my-url-map 
           --ssl-certificates my-ssl-cert
   

3. Create a Global Forwarding Rule for HTTPS:

   gcloud compute forwarding-rules create my-https-rule 
           --global 
           --target-https-proxy my-https-proxy 
           --ports 443
   

1. Create an SSL Certificate:

   gcloud compute ssl-certificates create my-ssl-cert 
           --certificate /path/to/cert.pem 
           --private-key /path/to/key.pem
   

2. Create a Target HTTPS Proxy:

   gcloud compute target-https-proxies create my-https-proxy 
           --url-map my-url-map 
           --ssl-certificates my-ssl-cert
   

3. Create a Global Forwarding Rule for HTTPS:

   gcloud compute forwarding-rules create my-https-rule 
           --global 
           --target-https-proxy my-https-proxy 
           --ports 443
   

• Health Check Configuration: Ensure that your health checks are correctly configured to match the expected response from your backend instances.
• Instance Group Location: Make sure your instance groups are in the same region as your backend services.
• SSL Certificates: Use managed SSL certificates for easier management and automatic renewal.

In this section, you learned about the different types of load balancers available in GCP and how to set up an HTTP load balancer. You also practiced creating an HTTPS load balancer. Understanding and implementing load balancing is crucial for distributing traffic efficiently and ensuring high availability and reliability of your applications. In the next section, we will dive into Cloud CDN to further optimize your content delivery.