Spring Boot Redis Cluster Configuration

问题：

  1、集群信息已变更(添加或停节点)，RedisTemplate无法访问节点
  2、集群未读写分离，主读写压力大。

解决：

  1、版本：spring boot 2.1.3.RELEASE、spring Cloud Greenwich.RELEASE
  2、依赖：spring-boot-starter-data-redis、commons-pool2           
  2、RedisConfiguration类：

import io.lettuce.core.ReadFrom;
import io.lettuce.core.cluster.ClusterClientOptions;
import io.lettuce.core.cluster.ClusterTopologyRefreshOptions;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.data.redis.RedisProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisClusterConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceClientConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.time.Duration;

/**
 * @author pgig
 * @date 2019/3/21
 */
@Configuration
public class RedisConfiguration {


    @Autowired
    private RedisProperties redisProperties;

    @Value("${redis.maxRedirects:3}")
    private int maxRedirects;

    @Value("${redis.refreshTime:5}")
    private int refreshTime;

    @Bean
    public LettuceConnectionFactory redisConnectionFactory() {

        RedisClusterConfiguration redisClusterConfiguration = new RedisClusterConfiguration(redisProperties.getCluster().getNodes());

        redisClusterConfiguration.setMaxRedirects(maxRedirects);

        //支持自适应集群拓扑刷新和静态刷新源
        ClusterTopologyRefreshOptions clusterTopologyRefreshOptions =  ClusterTopologyRefreshOptions.builder()
                .enablePeriodicRefresh()
                .enableAllAdaptiveRefreshTriggers()
                .refreshPeriod(Duration.ofSeconds(refreshTime))
                .build();

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

        //从优先，读写分离，读从可能存在不一致，最终一致性CP
        LettuceClientConfiguration lettuceClientConfiguration = LettuceClientConfiguration.builder()
                .readFrom(ReadFrom.SLAVE_PREFERRED)
                .clientOptions(clusterClientOptions).build();

        return new LettuceConnectionFactory(redisClusterConfiguration, lettuceClientConfiguration);
    }



    @Bean
    public RedisTemplate redisTemplate(LettuceConnectionFactory redisConnectionFactory) {
        RedisTemplate redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }

}

参考：
  1、Configuring Spring Data Redis with Lettuce for Redis master/slave
  2、Support adaptive cluster topology refreshing and static refresh sources