redis叢集主從之讀寫分離

1、叢集部署 這裡就不詳細贅述如何部署主從叢集了，一般都是使用slaveOf配置來進行初始化配置。

2、與springboot整合實現讀寫分離 通過註解實現呼叫層讀寫分離，然後根據取模運算來確定訪問哪個讀庫

• 在springcloud配置中心增加redis配置：

配置讀寫節點

spring:
  redis:
    database: 0
    pool:
      max-active: 8
      max-idle: 9
      max-wait: -1
      min-idle: 0
    redis-master:
      host: 192.168.1.1
      prot: 6379
      password: 
      testOnBorrow: false
    redis-slave1:
      host: 192.168.1.2
      prot: 6379
      password:
      testOnBorrow: false
    redis-slave2:
      host: 192.168.1.3
      prot: 6379
      password:
      testOnBorrow: false
 

• 增加自動配置類

如下：

@Configuration
public class RedisConfiguration {

    @Value("${spring.redis.pool.max-idle}")
    private int maxIdle;
    @Value("${spring.redis.pool.max-active}")
    private int maxTotal;
    @Value("${spring.redis.database}")
    private int index;
    @Value("${spring.redis.pool.max-wait}")
    private long maxWaitMillis;
    

    @Bean(name = "redisMasterTemplate")
    public StringRedisTemplate redisMasterTemplate(@Value("${spring.redis-master.host}") String hostName,
            @Value("${spring.redis-master.port}") int port, @Value("${spring.redis-master.password}") String password, @Value("${spring.redis-master.testOnBorrow}") boolean testOnBorrow) {
        StringRedisTemplate temple = new StringRedisTemplate();
        temple.setConnectionFactory(
                connectionFactory(hostName, port, password, maxIdle, maxTotal, index, maxWaitMillis, testOnBorrow));

        return temple;
    }

    @Bean(name = "redisSlave1Template")
    public StringRedisTemplate redisSlave1Template(@Value("${spring.redis-slave1.host}") String hostName,
            @Value("${spring.redis-slave1.port}") int port, @Value("${spring.redis-slave1.password}") String password, @Value("${spring.redis-slave1.testOnBorrow}") boolean testOnBorrow) {
        StringRedisTemplate temple = new StringRedisTemplate();
        temple.setConnectionFactory(
                connectionFactory(hostName, port, password, maxIdle, maxTotal, index, maxWaitMillis, testOnBorrow));

        return temple;
    }

    @Bean(name = "redisSlave1Template")
    public List<StringRedisTemplate> redisSlaveTemplate() {
        List<StringRedisTemplate> list = new ArrayList<StringRedisTemplate>();
        list.add(redisSlave1Template());
        list.add(redisSlave2Template());
        return list;
    }

    @Bean(name = "redisSlave2Template")
    public StringRedisTemplate redisSlave1Template(@Value("${spring.redis-slave2.host}") String hostName,
            @Value("${spring.redis-slave2.port}") int port, @Value("${spring.redis-slave2.password}") String password, @Value("${spring.redis-slave2.testOnBorrow}") boolean testOnBorrow) {
        StringRedisTemplate temple = new StringRedisTemplate();
        temple.setConnectionFactory(
                connectionFactory(hostName, port, password, maxIdle, maxTotal, index, maxWaitMillis, testOnBorrow));
        return temple;
    }

    public RedisConnectionFactory connectionFactory(String hostName, int port, String password, int maxIdle,
            int maxTotal, int index, long maxWaitMillis, boolean testOnBorrow) {
        JedisConnectionFactory jedis = new JedisConnectionFactory();
        jedis.setHostName(hostName);
        jedis.setPort(port);
        if (StringUtils.isNotEmpty(password)) {
            jedis.setPassword(password);
        }
        if (index != 0) {
            jedis.setDatabase(index);
        }
        jedis.setPoolConfig(poolCofig(maxIdle, maxTotal, maxWaitMillis, testOnBorrow));
        // 初始化連線pool
        jedis.afterPropertiesSet();
        RedisConnectionFactory factory = jedis;

        return factory;
    }

    public JedisPoolConfig poolCofig(int maxIdle, int maxTotal, long maxWaitMillis, boolean testOnBorrow) {
        JedisPoolConfig poolCofig = new JedisPoolConfig();
        poolCofig.setMaxIdle(maxIdle);
        poolCofig.setMaxTotal(maxTotal);
        poolCofig.setMaxWaitMillis(maxWaitMillis);
        poolCofig.setTestOnBorrow(testOnBorrow);
        return poolCofig;
    }
}
 

封裝呼叫介面

@Component
public class StringRedisTemplateProxy {

	@Autowired
	private StringRedisTemplate redisMasterTemplate; 
	
	@Autowired
	private List<StringRedisTemplate> redisSlaveList; 
	
	private int index=0;
	
	public void setValue(String key,String value) {
		redisMasterTemplate.opsForValue().set(key, value);
	}
	
	public String getValue(String key) {
		index++;
		return redisSlaveList.get(index).opsForValue().get(key);
	}
}
 

這裡缺點就是無法做到故障轉移，這裡就需要用到虛擬ip和指令碼定時監控。 1、使用一個虛擬ip指向redis master 2、如果從節點故障，可以採用重試機制來進行一次呼叫讀節點，如果是主節點故障，則需要通過指令碼自動將一個從節點切換成主節點，並將虛擬IP繫結在該節點上。