当Redis服务端网络波动或者挂掉重启后，Redis的客户端需要重启项目吗？大家肯定都说：肯定不需要重启呀，那么Redis的两种客户端：Jedis和Lettuce针对Redis网络波动或者挂掉重启，有什么失败策略呢？

1. 环境信息

Redis服务器环境：单点配置
Redis客户端环境：Jedis/Lettuce配置
配置信息如下：

    @Bean
    @Primary
    public StringRedisTemplate stringRedisTemplate(@Qualifier("jedisConnectionFactory") RedisConnectionFactory connectionFactory) {
        StringRedisTemplate stringRedisTemplate = new StringRedisTemplate();
        stringRedisTemplate.setConnectionFactory(connectionFactory);
        return stringRedisTemplate;
    }

Jedis连接工厂的配置：

    @Bean("connectionFactory")
    public LettuceConnectionFactory redisConnectionFactory() throws UnknownHostException {
        RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
        redisStandaloneConfiguration.setHostName("localhost");
        redisStandaloneConfiguration.setPort(6379);
        LettuceClientConfiguration.LettuceClientConfigurationBuilder lettuceClientConfigurationBuilder = LettuceClientConfiguration.builder();
        LettuceConnectionFactory factory = new LettuceConnectionFactory(redisStandaloneConfiguration,
                lettuceClientConfigurationBuilder.build());
        return factory;
    }

lettuce连接工厂的配置：

    @Bean("connectionFactory")
    public JedisConnectionFactory redisConnectionFactory() {
        RedisStandaloneConfiguration configuration = new RedisStandaloneConfiguration();
        configuration.setHostName("localhost");
        configuration.setPort(6379);
        configuration.setDatabase(0);
        JedisClientConfiguration.JedisPoolingClientConfigurationBuilder builder = (JedisClientConfiguration.JedisPoolingClientConfigurationBuilder) JedisClientConfiguration.builder();
        return new JedisConnectionFactory(configuration, builder.build());
    }

2. 测试流程

1. 启动服务，调用访问Redis的http；
2. kill掉Redis服务端，调用访问Redis的http；
3. 恢复Redis服务端，调用访问Redis的http；

服务端模拟操作.png

• Redis服务端挂掉后，Jedis请求立即失败

jedis客户端的请求.png

• Redis服务端挂掉后，Lettuce请求会被阻塞

  
  image.png

image.png

3. 最终结论

无论是Jedis客户端还是Lettuce客户端，当Redis服务器恢复后，均无需重启项目，项目的Redis访问请求即可恢复。

但是：Jedis客户端的请求会立刻失败；Lettuce的请求会被阻塞，由定时发起reconnect操作。