Redis-backed limiter

Use this example when rate-limit state must be visible to more than one application process.

Prerequisites

• Go 1.24 or newer
• Redis reachable at localhost:6379

For a disposable local Redis:

docker run --rm --name gorl-redis -p 6379:6379 redis:7-alpine

Run

In a second terminal:

go run ./examples/redis

examples/redis/main.go

// Package main demonstrates the usage of the Redis-backed rate limiter.
package main

import (
    "context"
    "fmt"
    "time"

    "github.com/AliRizaAynaci/gorl/v2"
    "github.com/AliRizaAynaci/gorl/v2/core"
)

// main runs a simple demonstration of the rate limiter using a Redis backend.
func main() {
    limiter, err := gorl.New(core.Config{
        Strategy: core.TokenBucket,
        Limit:    4,
        Window:   10 * time.Second,
        RedisURL: "redis://localhost:6379/0",
        FailOpen: true,
    })
    if err != nil {
        panic(err)
    }
    defer limiter.Close()

    ctx := context.Background()
    start := time.Now()
    for i := 1; i <= 15; i++ {
        res, err := limiter.Allow(ctx, "127.0.0.1")
        elapsed := time.Since(start).Seconds()
        timestamp := time.Now().Format("15:04:05")

        fmt.Printf("[%s +%.1fs] Request #%d: allowed=%v, remaining=%d, retry_after=%v, err=%v\n",
            timestamp, elapsed, i, res.Allowed, res.Remaining, res.RetryAfter, err,
        )

        time.Sleep(1000 * time.Millisecond)
    }
}

Expected behavior

The constructor connects to Redis, then a token bucket with capacity four makes fifteen decisions over roughly fifteen seconds. Multiple runs using the same Redis database and key observe shared state.

Production cautions

The example deliberately uses a local unauthenticated URL and FailOpen: true. Do not copy those policy choices blindly. Protect credentials, measure Redis round-trip latency, monitor evictions, and read Redis in production before deployment.