Spring boot2.x与redis Lettuce集成操作redis集群case

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Spring boot2.x与redis Lettuce集成操作redis集群case

场景

redis cluster集群有一台机崩了之后，后台服务的redis会一直报错，无法连接到redis集群。通过命令查看redis集群，发现redis cluster集群是正常的，备用的slave机器已经升级为master。

猜想与验证

初步猜测是Spring-redis的连接池框架在redis的其中一台master机器崩了之后，并没有刷新连接池的连接，仍然连接的是挂掉的那台redis服务器. 通过寻找资料在Spring boot2.x改为默认使用Lettuce框架与redis 连接在Lettuce官文档中找到了关RedisCluster的相关信息 《Refreshing the cluster topologyview》文中大概意思是自适应拓扑刷新（Adaptive updates）与定时拓扑刷新（Periodicupdates） 是默认关闭的，可以通过代码打开。

验证

• 官方给出代码示例如下:

    RedisClusterClient clusterClient =
    RedisClusterClient.create(RedisURI.create("localhost", 6379));
  
    ClusterTopologyRefreshOptions topologyRefreshOptions = ClusterTopologyRefreshOptions.builder()
                                    .enablePeriodicRefresh(10, TimeUnit.MINUTES)
                                    .build();
  
    clusterClient.setOptions(ClusterClientOptions.builder()
                                    .topologyRefreshOptions(topologyRefreshOptions)
                                    .build());
    ...
  
    clusterClient.shutdown();
  
  
    RedisURI node1 = RedisURI.create("node1", 6379);
    RedisURI node2 = RedisURI.create("node2", 6379);
  
    RedisClusterClient clusterClient = RedisClusterClient.create(Arrays.asList(node1, node2));
  
    ClusterTopologyRefreshOptions topologyRefreshOptions = ClusterTopologyRefreshOptions.builder()
                                    .enableAdaptiveRefreshTrigger(RefreshTrigger.MOVED_REDIRECT, RefreshTrigger.PERSISTENT_RECONNECTS)
                                    .adaptiveRefreshTriggersTimeout(30, TimeUnit.SECONDS)
                                    .build();
  
    clusterClient.setOptions(ClusterClientOptions.builder()
                                    .topologyRefreshOptions(topologyRefreshOptions)
                                    .build());
    ...
  
    clusterClient.shutdown();
  

• 修改在Spring boot2.x中配置连接redis cluster客户端代码如下:

    @Configuration
    public class LettuceRedisConfig {
  
        @Autowired
        private RedisProperties redisProperties;
  
        [@Bean](https://my.oschina.net/bean)
        public RedisTemplate redisTemplate(@Qualifier("lettuceConnectionFactoryUvPv") RedisConnectionFactory lettuceConnectionFactoryUvPv) {
            RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();
            template.setConnectionFactory(lettuceConnectionFactoryUvPv);
            Jackson2JsonRedisSerializer jackson2JsonRedisSerializer =
                    new Jackson2JsonRedisSerializer(Object.class);
            ObjectMapper om = new ObjectMapper();
            om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
            jackson2JsonRedisSerializer.setObjectMapper(om);
            StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
            template.setKeySerializer(stringRedisSerializer);
            template.setHashKeySerializer(stringRedisSerializer);
            template.setValueSerializer(jackson2JsonRedisSerializer);
            template.setHashValueSerializer(jackson2JsonRedisSerializer);
            template.afterPropertiesSet();
            return template;
        }
  
  
        @Bean(destroyMethod = "destroy")
        public LettuceConnectionFactory lettuceConnectionFactoryUvPv(){
  
            List<String> clusterNodes = redisProperties.getCluster().getNodes();
            Set<RedisNode> nodes = new HashSet<RedisNode>();
            clusterNodes.forEach(address -> nodes.add(new RedisNode(address.split(":")[0].trim(),
                    Integer.parseInt(address.split(":")[1]))));
            RedisClusterConfiguration clusterConfiguration = new RedisClusterConfiguration();
            clusterConfiguration.setClusterNodes(nodes);
            clusterConfiguration.setPassword(RedisPassword.of(redisProperties.getPassword()));
            clusterConfiguration.setMaxRedirects(redisProperties.getCluster().getMaxRedirects());
  
            GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
            poolConfig.setMaxIdle(redisProperties.getLettuce().getPool().getMaxIdle());
            poolConfig.setMinIdle(redisProperties.getLettuce().getPool().getMinIdle());
            poolConfig.setMaxTotal(redisProperties.getLettuce().getPool().getMaxActive());
  
            return new LettuceConnectionFactory(clusterConfiguration,
                    getLettuceClientConfiguration(poolConfig));
        }
  
        private LettuceClientConfiguration getLettuceClientConfiguration(GenericObjectPoolConfig genericObjectPoolConfig) {
            ClusterTopologyRefreshOptions topologyRefreshOptions =
                    ClusterTopologyRefreshOptions.builder()
                    .enableAllAdaptiveRefreshTriggers()
                    .adaptiveRefreshTriggersTimeout(Duration.ofSeconds(25)) 
                    .enablePeriodicRefresh(Duration.ofSeconds(20))  
                    .build();
            return LettucePoolingClientConfiguration.builder()
                    .poolConfig(genericObjectPoolConfig)
                    .clientOptions(ClusterClientOptions.builder().topologyRefreshOptions(topologyRefreshOptions).build())
                    .build();
        }
    }
  

在上述代码中需要设置自动刷新让其连接池连接新的master节点，方可避免问题不需要再去换成jedis，有点人可能会说直接替换掉lettuce采用jedis这种方式也行就是效率会有降低。 还是推荐使用lettuce官方也是推荐使用它。

来源：oschina

链接：https://my.oschina.net/VILLE/blog/3154994