hongery / rlock

💐 Redis Distributed Lock

Redis Distributed Lock

中文说明

Why use distributed lock?

1. Some program processes/services may competing for resources, they distributed deployed in different position at many machines, ensure free from side effects such dirty read/write, we should lock those resources before make logic action.
2. Some crontab task may distributed deployed, we know they will run at the same time when time reach, ensure crontab task can execute one by one, we make a task lock!
3. Other Parallel security.

Some cases: 1.avoid repeated order pay in E-commerce business, we lock the order. 2.multi copy of crontab statistical task run at night, we lock task.

We are support:

1. Single Mode Redis: Stand-alone Redis.
2. Sentinel Mode Redis: Pseudo Cluster Redis.

How to use

Simple：

go get -v github.com/hunterhug/rlock

Example

package main

import (
	"fmt"
	"github.com/hunterhug/rlock"
)

func main() {
	// 1. config redis
	redisHost := "127.0.0.1:6379"
	redisDb := 0
	redisPass := "hunterhug" // may redis has password
	config := rlock.NewRedisSingleModeConfig(redisHost, redisDb, redisPass)
	pool, err := rlock.NewRedisPool(config)
	if err != nil {
		fmt.Println("redis init err:", err.Error())
		return
	}

	// 2. new a lock factory
	lockFactory := rlock.New(pool)
	lockFactory.SetRetryCount(3).SetRetryMillSecondDelay(200) // set retry time and delay mill second

	// 3. lock a resource
	resourceName := "gold"
	expireMillSecond := 10 * 1000 // 10s
	lock, err := lockFactory.Lock(resourceName, expireMillSecond)
	if err != nil {
		fmt.Println("lock err:", err.Error())
		return
	}

	// lock empty point not lock
	if lock == nil {
		fmt.Println("lock err:", "can not lock")
		return
	}

	// add lock success
	fmt.Printf("add lock success:%#v\n", lock)


	// 4. unlock a resource
	isUnlock, err := lockFactory.UnLock(*lock)
	if err != nil {
		fmt.Println("lock err:", err.Error())
		return
	}

	fmt.Println("lock unlock:", isUnlock)

	// unlock a resource again
	isUnlock, err = lockFactory.UnLock(*lock)
	if err != nil {
		fmt.Println("lock err:", err.Error())
		return
	}

	fmt.Println("lock unlock:", isUnlock)
}