Load balancer types comparison in GCP - Commands & Configuration

Introduction

When you have many users trying to access your app, you need a way to share the work across several servers. Load balancers help by spreading the traffic so no single server gets overwhelmed. Google Cloud offers different types of load balancers for different needs.

When you want to share user requests across multiple servers to keep your app fast and reliable.

When you need to balance traffic for a website that uses HTTP or HTTPS protocols.

When you want to distribute traffic inside your private network without exposing it to the internet.

When you want to balance traffic for TCP or UDP applications like games or chat servers.

When you want to route traffic based on the location of your users to reduce delay.

Commands

This command lists all forwarding rules, which show active load balancers and their types in your Google Cloud project.

Terminal

gcloud compute forwarding-rules list

Expected Output

NAME                 REGION       IP_ADDRESS      IP_PROTOCOL  TARGET

example-http-lb       us-central1  34.68.123.45   TCP          target-http-proxy-1

This command lists backend services that are used by load balancers to send traffic to groups of servers.

Terminal

gcloud compute backend-services list

Expected Output

NAME                 PROTOCOL  BACKENDS

example-backend       HTTP      instance-group-1

This command shows how HTTP(S) load balancers route traffic based on URL paths or hostnames.

Terminal

gcloud compute url-maps describe example-url-map

Expected Output

defaultService: https://www.googleapis.com/compute/v1/projects/my-project/global/backendServices/example-backend

hostRules:

- hosts:

  - '*'

  pathMatcher: path-matcher-1

This command lists target pools used by network load balancers to distribute traffic to instances.

Terminal

gcloud compute target-pools list

Expected Output

NAME                 REGION       INSTANCES

example-target-pool   us-central1  instance-1,instance-2

Key Concept

If you remember nothing else, remember: different load balancers in Google Cloud serve different traffic types and use cases like HTTP(S), TCP/UDP, or internal-only traffic.

Common Mistakes

Trying to use an HTTP(S) load balancer for TCP traffic.

HTTP(S) load balancers only handle web traffic and won't work for raw TCP or UDP connections.

Use a TCP/UDP network load balancer for non-web traffic.

Not checking the forwarding rules to see which load balancers are active.

Without checking forwarding rules, you might not know which load balancer is handling your traffic.

Always list forwarding rules to verify load balancer setup.

Summary

Use 'gcloud compute forwarding-rules list' to see active load balancers and their types.

Use 'gcloud compute backend-services list' to check backend groups serving traffic.

Use 'gcloud compute url-maps describe' to understand HTTP(S) routing rules.

Use 'gcloud compute target-pools list' to see instance groups behind network load balancers.