ratelimit

Distributed rate-limit library based on Redis

Overview

The goal of this library is to be able to implement distributed rate limit functions simply and rudely. Similar to the usage of the ID generator, the client takes back the data from Redis - batch data (just a value here), as long as it Is not consumed.it doesn't exceed rate-limit.

• 中文 README

Advantage

• Less dependencies, only rely on Redis, no special services required
• use Redis own clock, The clients no need to have the same clock
• Thread (coroutine) security
• Low system overhead and little pressure on redis

How to get

go get github.com/vearne/ratelimit

Usage

1. create redis.Client

with "github.com/go-redis/redis"

	client := redis.NewClient(&redis.Options{
		Addr:     "localhost:6379",
		Password: "xxx", // no password set
		DB:       0,  // use default DB
	})

2. create RateLimiter

	limiter, _ := ratelimit.NewRedisRateLimiter(client,
		"push",
		1 * time.Second,
		200,
		10,
		ratelimit.TokenBucketAlg,
	)

Indicates that 200 operations per second are allowed

	limiter, _ := ratelimit.NewRedisRateLimiter(client,
		"push",
		1 * time.Minute,
		200,
		10,
		ratelimit.TokenBucketAlg,
	)

Indicates that 200 operations per minute are allowed

The function prototype is as follows:

func NewRedisRateLimiter(client *redis.Client, key string,
	duration time.Duration, throughput int, batchSize int, alg int) (*RedisRateLimiter, error)

NOTICE rate-limit = throughput / duration In addition, in order to ensure that the performance is high enough, the minimum precision of duration is seconds.

Complete example

package main

import (
	"fmt"
	"github.com/go-redis/redis"
	"github.com/vearne/ratelimit"
	"math/rand"
	"sync"
	"time"
)

func consume(r *ratelimit.RedisRateLimiter, group *sync.WaitGroup) {
	for {
		if r.Take() {
			group.Done()
		} else {
			time.Sleep(time.Duration(rand.Intn(10)+1) * time.Millisecond)
		}
	}
}

func main() {
	client := redis.NewClient(&redis.Options{
		Addr: "localhost:6379",
		Password: "xxxxx", // password set
		DB: 0, // use default DB
	})

	limiter, _ := ratelimit.NewRedisRateLimiter(client,
		"push",
		1*time.Second,
		500,
		10,
		//ratelimit.CounterAlg,
		ratelimit.TokenBucketAlg,
	)

	var wg sync.WaitGroup
	total := 5000
	wg.Add(total)
	start := time.Now()
	for i := 0; i < 100; i++ {
		go consume(limiter, &wg)
	}
	wg.Wait()
	cost := time.Since(start)
	fmt.Println("cost", time.Since(start), "rate", float64(total)/cost.Seconds())
}

Dependency

go-redis/redis

Thanks

The development of the module was inspired by the Reference 1.

Reference

1. Performance million/s: Tencent lightweight global flow control program