Load Balancer - Polaris Integration Example

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

Description

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

• Service registration using Polaris
• Client-side load balancing
• Round-robin load balancing strategy
• HTTP service communication
• Local cache and logging configuration

Requirements

• Go 1.22 or higher
• Git
• GoFrame
• GoFrame Polaris Registry

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 Polaris server:

   # Using docker
   docker run -d --name polaris \
      -p 8090:8090 -p 8091:8091 -p 8093:8093 -p 9090:9090 -p 9091:9091 \
      polarismesh/polaris-standalone:v1.17.2

Configuration

The example uses the following Polaris configurations:

• Server address: 127.0.0.1:8091
• Local cache directory: <TempDir>/polaris/backup
• Log directory: <TempDir>/polaris/log
• Service TTL: 10 seconds

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 Polaris
   • Simple HTTP endpoint that returns "Hello world"
   • Automatic service discovery registration
   • Configurable TTL for service registration

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

   • Service discovery using Polaris
   • Round-robin load balancing strategy
   • Multiple request demonstration with timing information
   • Automatic service discovery and load balancing
   • Local cache and logging configuration

Notes

• The example uses Polaris for service registration and discovery
• Round-robin load balancing is implemented for demonstration
• The client automatically handles service discovery and load balancing
• Local cache is used to improve performance
• Logging is configured for better debugging