使用Lettuce连接到AWS ElastiCache Redis的Spring会话

Question

null

<!-- Lettuce Configuration -->
<bean class="org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory">
    <constructor-arg ref="redisClusterConfiguration"/>
</bean>

<!-- Redis Cluster Configuration -->
<bean id="redisClusterConfiguration" class="org.springframework.data.redis.connection.RedisClusterConfiguration">
    <constructor-arg>
        <list>
            <value><!-- AMAZON SINGLE ENDPOINT HERE --></value>
         </list>
     </constructor-arg>
 </bean>

myserver-0001-001
cache-cluster
Monday, July 6, 2020 at 8:25:32 PM UTC+3
Finished recovery for cache nodes 0001
 
myserver-0001-001
cache-cluster
Monday, July 6, 2020 at 8:20:38 PM UTC+3
Recovering cache nodes 0001
 
myserver
replication-group
Monday, July 6, 2020 at 8:19:14 PM UTC+3
Failover to replica node myserver-0001-002 completed
 
myserver
replication-group
Monday, July 6, 2020 at 8:17:59 PM UTC+3
Test Failover API called for node group 0001

org.springframework.data.redis.RedisSystemException: Error in execution; nested exception is io.lettuce.core.RedisCommandExecutionException: CLUSTERDOWN The cluster is down

endpoint:6379> cluster nodes
ffe51ecc6a8c1f32ab3774eb8f159bd64392dc14 172.31.11.216:6379@1122 master - 0 1594114396000 9 connected 0-8191
f8ff7a20f4c493b63ba65f107f575631faa4eb1b 172.31.11.52:6379@1122 slave 4ab10ca0a6a932179432769fcba7fab0faba01f7 0 1594114396872 2 connected
c18fee0e47800d792676c7d14782d81d7d1684e8 172.31.10.64:6379@1122 master,fail - 1594114079948 1594114077000 8 connected
4ab10ca0a6a932179432769fcba7fab0faba01f7 172.31.10.84:6379@1122 myself,master - 0 1594114395000 2 connected 8192-16383
endpoint:6379> cluster nodes
ffe51ecc6a8c1f32ab3774eb8f159bd64392dc14 172.31.11.216:6379@1122 master - 0 1594114461262 9 connected 0-8191
f8ff7a20f4c493b63ba65f107f575631faa4eb1b 172.31.11.52:6379@1122 slave 4ab10ca0a6a932179432769fcba7fab0faba01f7 0 1594114460000 2 connected
6a7339ae4df3c78e31c9cc8fd8cec4803eed5fc1 172.31.10.64:6379@1122 master - 0 1594114460256 0 connected
c18fee0e47800d792676c7d14782d81d7d1684e8 172.31.10.64:6379@1122 master,fail - 1594114079948 1594114077000 8 connected
4ab10ca0a6a932179432769fcba7fab0faba01f7 172.31.10.84:6379@1122 myself,master - 0 1594114458000 2 connected 8192-16383
endpoint:6379> cluster nodes
ffe51ecc6a8c1f32ab3774eb8f159bd64392dc14 172.31.11.216:6379@1122 master - 0 1594114509000 9 connected 0-8191
f8ff7a20f4c493b63ba65f107f575631faa4eb1b 172.31.11.52:6379@1122 slave 4ab10ca0a6a932179432769fcba7fab0faba01f7 0 1594114510552 2 connected
6a7339ae4df3c78e31c9cc8fd8cec4803eed5fc1 172.31.10.64:6379@1122 slave ffe51ecc6a8c1f32ab3774eb8f159bd64392dc14 0 1594114510000 9 connected
c18fee0e47800d792676c7d14782d81d7d1684e8 172.31.10.64:6379@1122 master,fail - 1594114079948 1594114077000 8 connected
4ab10ca0a6a932179432769fcba7fab0faba01f7 172.31.10.84:6379@1122 myself,master - 0 1594114508000 2 connected 8192-16383
endpoint:6379> cluster nodes
ffe51ecc6a8c1f32ab3774eb8f159bd64392dc14 172.31.11.216:6379@1122 master - 0 1594114548000 9 connected 0-8191
f8ff7a20f4c493b63ba65f107f575631faa4eb1b 172.31.11.52:6379@1122 slave 4ab10ca0a6a932179432769fcba7fab0faba01f7 0 1594114548783 2 connected
6a7339ae4df3c78e31c9cc8fd8cec4803eed5fc1 172.31.10.64:6379@1122 slave ffe51ecc6a8c1f32ab3774eb8f159bd64392dc14 0 1594114547776 9 connected
4ab10ca0a6a932179432769fcba7fab0faba01f7 172.31.10.84:6379@1122 myself,master - 0 1594114547000 2 connected 8192-16383

难道我的配置还不够让生菜连上新升职的师傅吗？我是否需要在Lettuce中启用一个不同的模式，以便它能够接收Redis的通知并切换到新的master（例如，拓扑刷新）？

另外，Lettuce是如何处理来自AWS的单个endpoint的？它是解析IPs然后使用它们吗？它们被缓存了吗？

如果我想让读取从所有四个节点发生，我的配置是否足够？在Redis集群中（即，即使在AWS上下文之外），当从服务器提升为主服务器时，客户机是轮询以获取信息，还是集群以某种方式将信息推送到客户机？

启用了调试，并使用断点拦截bean创建和配置拓扑，以这种方式刷新。似乎通过ClusterClientOptions的构造函数启用ClusterTopologyRefreshTask:

protected ClusterClientOptions(Builder builder) {
 
        super(builder);
 
        this.validateClusterNodeMembership = builder.validateClusterNodeMembership;
        this.maxRedirects = builder.maxRedirects;
 
        ClusterTopologyRefreshOptions refreshOptions = builder.topologyRefreshOptions;
 
        if (refreshOptions == null) {
            refreshOptions = ClusterTopologyRefreshOptions.builder() //
                    .enablePeriodicRefresh(DEFAULT_REFRESH_CLUSTER_VIEW) // Breakpoint here and enter to enable refreshing
                    .refreshPeriod(DEFAULT_REFRESH_PERIOD_DURATION) // Breakpoint here and enter to set the refresh interval
                    .closeStaleConnections(builder.closeStaleConnections) //
                    .build();
        }
 
        this.topologyRefreshOptions = refreshOptions;
    }

这似乎是令人耳目一新的OK，但现在的问题是，当Lettuce通过Spring会话而不是作为Redis的普通客户端使用时，如何配置它？

Answer 1

当我在思考我的问题时，我意识到我还没有回答那个问题！所以这里是为了防止有人有同样的问题。

我最后做的是为Redis创建一个配置bean，而不是使用XML。守则如下：

@EnableRedisHttpSession
public class RedisConfig {
  private static final List<String> clusterNodes = Arrays.asList(System.getProperty("redis.endpoint"));

  @Bean
  public static ConfigureRedisAction configureRedisAction() {
    return ConfigureRedisAction.NO_OP;
  }

  @Bean(destroyMethod = "destroy")
  public LettuceConnectionFactory lettuceConnectionFactory() {
    RedisClusterConfiguration redisClusterConfiguration = new RedisClusterConfiguration(clusterNodes);
    return new LettuceConnectionFactory(redisClusterConfiguration, getLettuceClientConfiguration());
  }


  private LettuceClientConfiguration getLettuceClientConfiguration() {
    ClusterTopologyRefreshOptions topologyRefreshOptions = ClusterTopologyRefreshOptions.builder().enablePeriodicRefresh(Duration.ofSeconds(30)).build();

    ClusterClientOptions clusterClientOptions = ClusterClientOptions.builder().topologyRefreshOptions(topologyRefreshOptions).build();

    return LettucePoolingClientConfiguration.builder().clientOptions(clusterClientOptions).build();
  }
}

然后，我没有通过XML注册ContextLoaderListener，而是使用了一个初始化器，如下所示：

public class Initializer extends AbstractHttpSessionApplicationInitializer {
  public Initializer() {
    super(RedisConfig.class);
  }
}