Load Balancer - HTTP Service Example

Code Source: https://github.com/gogf/examples/tree/main/balancer/http

Description

This example demonstrates how to implement HTTP service load balancing with GoFrame. It shows:

• Service registration using etcd
• Client-side load balancing
• Round-robin load balancing strategy
• HTTP service communication

Requirements

• Go 1.22 or higher
• Git
• GoFrame

Structure

.
├── client/           # HTTP client implementation with load balancing
│   └── client.go     # Client code with round-robin balancer
├── server/           # HTTP server implementation
│   └── server.go     # Server code with service registration
├── go.mod            # Go module file
└── go.sum            # Go module checksums

Prerequisites

1. Running etcd server:

   # Using docker
   docker run -d --name etcd-server \
      --publish 2379:2379 \
      --publish 2380:2380 \
      --env ALLOW_NONE_AUTHENTICATION=yes \
      bitnami/etcd:latest

Usage

1. Start multiple server instances (use random different ports):

   # Terminal 1
   cd server
   go run server.go
   
   # Terminal 2
   cd server
   go run server.go
   
   # Terminal 3
   cd server
   go run server.go

2. Run the client to test load balancing:

   cd client
   go run client.go

Implementation Details

1. Server Implementation (server/server.go):

   • HTTP server setup using GoFrame
   • Service registration with etcd
   • Simple HTTP endpoint that returns "Hello world"
   • Automatic service discovery registration

2. Client Implementation (client/client.go):

   • Service discovery using etcd
   • Round-robin load balancing strategy
   • Multiple request demonstration
   • Automatic service discovery and load balancing

Notes

• The example uses etcd for service registration and discovery
• Round-robin load balancing is implemented for demonstration
• The client automatically handles service discovery and load balancing
• Multiple server instances can be started to demonstrate load distribution