Redis架构设计

主从复制架构

主从复制实现读写分离，Master负责写入，Slave负责读取，通过RDB和AOF实现数据同步。

# redis-slave.conf
replicaof 192.168.1.100 6379
masterauth yourpassword
replica-read-only yes

@Configuration
public class RedisMasterSlaveConfig {

    @Bean
    public RedisConnectionFactory masterConnection() {
        LettuceConnectionFactory factory = new LettuceConnectionFactory(
            new RedisStandaloneConfiguration("master-host", 6379));
        return factory;
    }

    @Bean
    @Qualifier("slave")
    public RedisConnectionFactory slaveConnection() {
        LettuceConnectionFactory factory = new LettuceConnectionFactory(
            new RedisStandaloneConfiguration("slave-host", 6380));
        factory.setReadOnly(true);
        return factory;
    }
}

哨兵模式

Sentinel模式提供自动故障转移，监控Master状态并在宕机时自动选举新Master。

# sentinel.conf
sentinel monitor mymaster 192.168.1.100 6379 2
sentinel down-after-milliseconds mymaster 5000
sentinel failover-timeout mymaster 60000
sentinel parallel-syncs mymaster 1

@Configuration
public class RedisSentinelConfig {

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        RedisSentinelConfiguration sentinelConfig = new RedisSentinelConfiguration()
            .master("mymaster")
            .sentinel("sentinel1", 26379)
            .sentinel("sentinel2", 26379)
            .sentinel("sentinel3", 26379);
        sentinelConfig.setPassword(RedisPassword.of("password"));
        return new LettuceConnectionFactory(sentinelConfig);
    }
}

Cluster模式

Redis Cluster通过16384个Hash Slot实现数据分片，支持水平扩展和自动故障转移。

# redis-cluster.conf
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

@Configuration
public class RedisClusterConfig {

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        RedisClusterConfiguration clusterConfig = new RedisClusterConfiguration()
            .addNode(new RedisNode("node1", 7000))
            .addNode(new RedisNode("node2", 7001))
            .addNode(new RedisNode("node3", 7002));
        clusterConfig.setMaxRedirects(3);
        return new LettuceConnectionFactory(clusterConfig);
    }
}

三种架构对比

特性	主从	哨兵	Cluster
高可用	手动切换	自动故障转移	自动故障转移
数据分片	不支持	不支持	16384 Slot
扩展性	读扩展	读扩展	读写扩展
复杂度	低	中	高