Redis Distributed Kit

this repo uses local sync lock and redis lock to provide high performance redis tools This redis kit is recommended in single redis machine.

performance test report

we use our redis kit to compare with their performance in concurrent environment.

1000qps * 10 count

machine	redisson	redis-kit	redis-kit (preload mode)
single instance (lock)	5286ms	5394ms	5184ms
two instances (lock)	5854ms	6620ms	6184ms
single instance (tryLock)	1271ms	738ms	720ms
two instances (tryLock)	2230ms	1714ms	1620ms

In conclusion, redis-kit is almost as fast as redisson when using lock, but when using tryLock the redis-kit is faster about 40% than redisson.

Import Redis Kit in your project

<dependency>
    <groupId>com.github.jsrdxzw</groupId>
    <artifactId>redis-kit-spring-boot-starter</artifactId>
    <version>2.0.0</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency> 

import com.jsrdxzw.redis.core.EnableRedisKit;

@EnableRedisKit
public class SpringBootApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootApplication.class, args);
    }
}

Use Distributed Lock

by default StringRedisTemplate which is provided by Spring is used, Of course you can choose other RedisTemplate by yourself.

@Configuration
public class DistributedLockConfiguration {
    @Bean
    public RedisLockFactory redisLockFactory(StringRedisTemplate redisTemplate) {
        return new DefaultRedisLockFactory(redisTemplate);
    }
}

use lock in your own business logic code

public class UserService {
    @Autowired
    private RedisLockFactory redisLockFactory;

    public void method() {
        RedisLock RLock = redisLockFactory.getLock("xzw");
        try {
            //RLock.lock(); by default the expire time is 60s
            // set expire time is recommended because busy waiting may cause deadlock
            // when redis machine is down..
            RLock.tryLock(30, TimeUnit.SECONDS);
            //RLock.tryLock(30, TimeUnit.SECONDS, 3);
            // your own logic
        } finally {
            RLock.unlock();
        }
    }
}

In the other way, annotations such as @DistributedLock, DistributedTryLock are also provided, please import the spring aop at the first place before using annotations.

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@ComponentScan
@SpringBootApplication(scanBasePackages = {"your.path", "com.jsrdxzw.redis"})
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

example of distributed lock by annotation

// @DistributedLock(lockKey = "your key")
@DistributedTryLock(lockKey = "your key", waitTime = 10)
public void method(){
        //...
        }

Notice

we don't recommend use redis lock with @Transactional because it may cause visibility problems.

@Transactional
public void reduceStock(Long id) {
    RedisLock lock = redisLockFactory.getLock("test2");
    try {
        lock.lock();
        SkuStock skuStock = skuStockRepository.getOne(id);
        Integer stock = skuStock.getStock();
        if (stock > 0) {
            log.info("stock is {}", stock);
            skuStock.setStock(stock - 1);
            skuStockRepository.save(skuStock);
        }
        longAdder.increment();
        log.info("这是第{}个请求, 改之前的stock:{}", longAdder.longValue(), stock);
    } finally {
        // when lock is released by one client, the other client will
        // get redis lock immediately when Transaction may not commit.
        // The other client will get old value by using Mysql.
        lock.unlock();
    }

}

enable preload mode

we support preload mode from v1.0.4 that means the lua script is preloaded before used. it can save memory and increase performance.

# by default preload mode is disabled 
redis-kit:
  preload: true

Redis Cache Example

it will get value from redis and if the key does not exist in redis it will do next process and put value in redis as cache. by default the expired time is 5 minutes. redis key can retrieve params from invoked function.

// key = id
@Cache(key = "id", expireTime = 10, timeUnit = TimeUnit.SECONDS)
public somethingVo testCache(Integer id) {
    //
}

// key = ro.title + ro.name
@Cache(key = "{title + name}", expireTime = 10, timeUnit = TimeUnit.SECONDS)
public somethingVo testCache(MerchandiseGroupRo ro) {
    //
}

// key = ro.title + id
@Cache(key = "{title}#id", expireTime = 10, timeUnit = TimeUnit.SECONDS)
public somethingVo testCache(MerchandiseGroupRo ro, Integer id) {
    //
}

// key = "hello"
@Cache(key = "hello", expireTime = 10, timeUnit = TimeUnit.SECONDS)
public somethingVo testCache() {
    //
}

it will remove redis value based on cache principle -- Cache aside

it is recommended to use @Transactional annotation when modifying cache values

@Transactional(rollbackFor = Throwable.class)
@Put(key = "xzw")
public Student methodName(){
        }

@Delete is same as @Put

@Transactional(rollbackFor = Throwable.class)
@Delete(key = "xzw")
public void methodName(){
        }

it will delete value from redis

rate limiter

import org.springframework.beans.factory.annotation.Autowired;

@Autowired
private RateLimit rateLimit;

boolean require=rateLimit.acquire("xzw",5,10);

it means we allow 5 requests per seconds, and when the request of per second is greater than 5, it will return false

we have provided three distributed limit rate algorithms:

1. counter [by default]
2. rolling window
3. token bucket

# you can change limit algorithm by overriding spring yaml file
redis-kit:
  rate-limit: 
    strategy: tokenBucket # default, rollingWindow
    bucket-size: 100 # default is 10

also, Spring AOP is used to support @Annotation features

import com.jsrdxzw.redis.ratelimit.RateLimiter;

@RateLimiter(key = "123", limit = 10, time = 10, expire = 30)
public Object method() {
    
}