Redis集群下过期key监听

1.　前言

在使用redis集群时，发现过期key始终监听不到。网上也没有现成的解决方案。于是想，既然不能监听集群，那我可以建立多个redis连接，分别对每个redis的key过期进行监听。以上做法可能不尽人意，目前也没找到好的解决方案，如果有好的想法，请留言告知哦！不多说，直接贴我自己的代码！

2.　代码实现

关于Redis集群配置代码此处不贴，直接贴配置监听类代码！

 redis.host1: 10.113.56.68
 redis.port1: 7030
 redis.host2: 10.113.56.68
 redis.port2: 7031
 redis.host3: 10.113.56.68
 redis.port3: 7032
 redis.host4: 10.113.56.68
 redis.port4: 7033
 redis.host5: 10.113.56.68
 redis.port5: 7034
 redis.host6: 10.113.56.68
 redis.port6: 7035

application配置类

 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.cache.CacheManager;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.redis.cache.RedisCacheManager;
 import org.springframework.data.redis.connection.RedisClusterConfiguration;
 import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
 import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.data.redis.listener.RedisMessageListenerContainer;
 import org.springframework.data.redis.serializer.StringRedisSerializer;
 import redis.clients.jedis.Jedis;
 import redis.clients.jedis.JedisPoolConfig;

 import java.util.Arrays;

 /**
  * @Author  xiabing5
  * @Create  2019/8/6 14:46
  * @Desc    监听redis中Key过期事件
  **/
 @Configuration
 public class RedisListenerConfig {

     @Value("${redis.host1}")
     private String host1;

     @Value("${redis.host2}")
     private String host2;

     @Value("${redis.host3}")
     private String host3;

     @Value("${redis.host4}")
     private String host4;

     @Value("${redis.host5}")
     private String host5;

     @Value("${redis.host6}")
     private String host6;

     @Value("${redis.port1}")
     private int port1;

     @Value("${redis.port2}")
     private int port2;

     @Value("${redis.port3}")
     private int port3;

     @Value("${redis.port4}")
     private int port4;

     @Value("${redis.port5}")
     private int port5;

     @Value("${redis.port6}")
     private int port6;

     @Bean
     JedisPoolConfig jedisPoolConfig(){
         JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
         jedisPoolConfig.setMaxIdle(100);
         jedisPoolConfig.setMaxWaitMillis(1000);
         return jedisPoolConfig;
     }

     // redis-cluster不支持key过期监听，建立多个连接，对每个redis节点进行监听
     @Bean
     RedisMessageListenerContainer redisContainer1() {
         final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
         JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
         jedisConnectionFactory.setHostName(host1);
         jedisConnectionFactory.setPort(port1);
         jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
         jedisConnectionFactory.afterPropertiesSet();
         container.setConnectionFactory(jedisConnectionFactory);
         return container;
     }

     @Bean
     RedisMessageListenerContainer redisContainer2() {
         final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
         JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
         jedisConnectionFactory.setHostName(host2);
         jedisConnectionFactory.setPort(port2);
         jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
         jedisConnectionFactory.afterPropertiesSet();
         container.setConnectionFactory(jedisConnectionFactory);
         return container;
     }

     @Bean
     RedisMessageListenerContainer redisContainer3() {
         final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
         JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
         jedisConnectionFactory.setHostName(host3);
         jedisConnectionFactory.setPort(port3);
         jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
         jedisConnectionFactory.afterPropertiesSet();
         container.setConnectionFactory(jedisConnectionFactory);
         return container;
     }

     @Bean
     RedisMessageListenerContainer redisContainer4() {
         final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
         JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
         jedisConnectionFactory.setHostName(host4);
         jedisConnectionFactory.setPort(port4);
         jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
         jedisConnectionFactory.afterPropertiesSet();
         container.setConnectionFactory(jedisConnectionFactory);
         return container;
     }

     @Bean
     RedisMessageListenerContainer redisContainer5() {
         final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
         JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
         jedisConnectionFactory.setHostName(host5);
         jedisConnectionFactory.setPort(port5);
         jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
         jedisConnectionFactory.afterPropertiesSet();
         container.setConnectionFactory(jedisConnectionFactory);
         return container;
     }

     @Bean
     RedisMessageListenerContainer redisContainer6() {
         final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
         JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
         jedisConnectionFactory.setHostName(host6);
         jedisConnectionFactory.setPort(port6);
         jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
         jedisConnectionFactory.afterPropertiesSet();
         container.setConnectionFactory(jedisConnectionFactory);
         return container;
     }

     @Bean
     RedisKeyExpirationListener redisKeyExpirationListener1() {
         return new RedisKeyExpirationListener(redisContainer1());
     }

     @Bean
     RedisKeyExpirationListener redisKeyExpirationListener2() {
         return new RedisKeyExpirationListener(redisContainer2());
     }

     @Bean
     RedisKeyExpirationListener redisKeyExpirationListener3() {
         return new RedisKeyExpirationListener(redisContainer3());
     }

     @Bean
     RedisKeyExpirationListener redisKeyExpirationListener4() {
         return new RedisKeyExpirationListener(redisContainer4());
     }

     @Bean
     RedisKeyExpirationListener redisKeyExpirationListener5() {
         return new RedisKeyExpirationListener(redisContainer5());
     }

     @Bean
     RedisKeyExpirationListener redisKeyExpirationListener6() {
         return new RedisKeyExpirationListener(redisContainer6());
     }

 }

Bean配置类

 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.redis.connection.Message;
 import org.springframework.data.redis.listener.KeyExpirationEventMessageListener;
 import org.springframework.data.redis.listener.RedisMessageListenerContainer;

 import java.util.Date;

 /**
  * @Author  xiabing5
  * @Create  2019/9/4 9:47
  * @Desc    redis过期监听
  **/
 public class RedisKeyExpirationListener extends KeyExpirationEventMessageListener {

     @Autowired
     RedisUtil redisUtil;

     @Autowired
     LoginUserStatisticsMapper loginUserStatisticsMapper;

     public RedisKeyExpirationListener(RedisMessageListenerContainer listenerContainer) {
         super(listenerContainer);
     }

     @Override
     public void onMessage(Message message, byte[] pattern) {
         // 用户做自己的业务处理即可,message.toString()可以获取失效的key
         String mesg = message.toString();      

     }
 }

监听操作类

3.　Redis防止过期key重复监听

对于项目集群情况下，部署多个服务后，容易出现redis过期被多个服务同时监听到，从而执行相同的业务逻辑，这不是我们期望的。单机部署下方法的同步可以采用synchronize关键字。但集群下，就得采用分布式锁。在需要加锁的地方，只要加锁和解锁即可。此处正好写到Redis，那就贴一个自己用的redis分布式锁。

 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 import redis.clients.jedis.Jedis;

 import java.util.Collections;
 import java.util.UUID;

 /**
  * @Author  xiabing5
  * @Create  2019/9/6 15:54
  * @Desc    redis分布式锁
  **/
 @Component
 public class RedisLock {

     @Autowired
     Jedis jedis;

     private static final String SET_IF_NOT_EXIST = "NX"; // NX表示如果不存在key就设置value
     private static final String SET_WITH_EXPIRE_TIME = "PX"; // PX表示毫秒

     // 加锁
     public String tryLock(String key,Long acquireTimeout) {
         // 生成随机value
         String identifierValue = UUID.randomUUID().toString();
         // 设置超时时间
         Long endTime = System.currentTimeMillis() + acquireTimeout;
         // 循环获取锁
         while (System.currentTimeMillis() < endTime) {
             String result = jedis.set(key,identifierValue, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, acquireTimeout);
             if("OK".equals(result)) {
                 return identifierValue;
             }
         }
         return null;
     }

     // 解锁
 //    public void delLock(String key,String identifierValue) {
 //        // 判断是否是同一把锁
 //        try{
 //            if(jedis.get(key).equals(identifierValue)){
 //                // 此处操作非原子性，容易造成释放非自己的锁
 //                jedis.del(key);
 //            }
 //        }catch(Exception e) {
 //            e.printStackTrace();
 //        }
 //    }

     // 使用Lua代码解锁
     public void delLock(String key,String identifierValue) {
         try{
             String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
             Long result = (Long) jedis.eval(script, Collections.singletonList(key), Collections.singletonList(identifierValue));
             if (1 == result) {
                System.out.println(result+"释放锁成功");
             } if (0 == result) {
                 System.out.println(result+"释放锁失败");
             }
         }catch (Exception e) {
             e.printStackTrace();
         }
     }

 }

Redis锁解决分布式同步问题

4.　总结

自己实现的一个小demo,废话比较少。小白自己写的配置类，理解有问题请留言！自己实现的方案感觉不妥，只是基本完成需求，还得继续研究。