redis 哨兵（sentinel）

redis哨兵

• 哨兵自动故障转移
• 自动通知应用最新master信息
• 无需担心，master挂了，程序不需要修改IP啥的，由哨兵自动完成

1. 修改sentinel.conf

protected-mode no # 默认只允许本机访问sentinel服务

工具类

package redis.client.sentinel;

import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.jedis.JedisSentinelPool;

import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * Created by dailin on 2017/7/27.
 */
public class Redis_Sentinel {

    public static JedisSentinelPool sentinelPool = null;
    private static JedisPoolConfig jedisPoolConfig = null;

    private Redis_Sentinel(){}

    private static  void initSentinelPool(Set<String> sentinels){
        synchronized (Redis_Sentinel.class){
            if (sentinelPool == null) {
                GenericObjectPoolConfig gPoolConfig=new GenericObjectPoolConfig();
                gPoolConfig.setMaxIdle(10);
                gPoolConfig.setMaxTotal(10);
                gPoolConfig.setMinIdle(1);
                gPoolConfig.setMaxWaitMillis(10);
                gPoolConfig.setJmxEnabled(true);
                sentinelPool = new JedisSentinelPool("mymaster",sentinels,gPoolConfig);
            }
        }
    }

    public static Jedis getJedis(Set<String> sentinels){
        initSentinelPool(sentinels);
        return sentinelPool.getResource();
    }
    public static void returnJedis(Jedis jedis){
        sentinelPool.returnResource(jedis);
    }
}

　　

测试类

import org.junit.Before;
import org.junit.Test;
import redis.client.sentinel.Redis_Sentinel;
import redis.clients.jedis.HostAndPort;
import redis.clients.jedis.Jedis;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Created by dailin on 2017/7/27.
 */
public class TestSentinel {
    Set<String> sentinel = null;
    @Before
    public void init()
    {
        sentinel = new HashSet<String>();
        sentinel.add("192.168.56.130:26379");
        sentinel.add("192.168.56.131:26379");
    }
    @Test
    public void testSentinel(){
        while(true) {
            try{
                Jedis jedis = Redis_Sentinel.getJedis(sentinel);
                String result = jedis.get("dai");
                HostAndPort currentHostMaster = Redis_Sentinel.sentinelPool.getCurrentHostMaster();
                System.out.println("master:"+currentHostMaster.getHost()+"-port:"+currentHostMaster.getPort());
                Redis_Sentinel.returnJedis(jedis);
                System.out.println(result);
            }catch (Exception e){
                e.printStackTrace();
            }
        }

    }
}

　　

这个测试类会一直访问redis，当master被停止后，程序抛出异常，过了一小会新的master被选出，程序又正常执行，所以使用jedis连接redis时，只需要传入sentinel的地址即可，自动在redis的master宕机后，自动更新连接新master信息。