redis的sentinel主从切换(failover)与Jedis线程池自动重连

本文介绍如何通过sentinel监控redis主从集群，并通过jedis自动切换ip和端口。

1、配置redis主从实例

10.93.21.21:6379

10.93.21.21:6389

10.93.21.21:6399

主从同步关系

master：10.93.21.21:6379

slave:10.93.21.21:6389，10.93.21.21:6399

master配置如下：

# 实例ip和端口
bind 10.93.21.21
port
# pid文件
pidfile redis_6379.pid
# 日志文件
logfile "/home/data_monitor/redis-3.2.9/log/6379.log"
# 持久化数据文件dir
dir /home/data_monitor/redis-3.2./data
# rdb 文件地址
dbfilename .rdb
# aof 文件地址
appendfilename "6379.aof"

slave配置如下(以6389为例)

# 实例ip和端口
bind 10.93.21.21
port
# master节点配置
slaveof 10.93.21.21
# pid文件
pidfile redis_6389.pid
# 日志文件
logfile "/home/data_monitor/redis-3.2.9/log/6389.log"
# 持久化数据文件dir
dir /home/data_monitor/redis-3.2./data
# rdb 文件地址
dbfilename .rdb
# aof 文件地址
appendfilename "6389.aof"

启动redis

bin/redis-server conf/.conf
bin/redis-server conf/.conf
bin/redis-server conf/.conf

验证一下

master

$ bin/redis-cli -h 10.93.21.21 -p
10.93.21.21:> info replication
# Replication
role:master
connected_slaves:
slave0:ip=10.93.21.21,port=,state=online,offset=,lag=
slave1:ip=10.93.21.21,port=,state=online,offset=,lag=
master_repl_offset:
repl_backlog_active:
repl_backlog_size:
repl_backlog_first_byte_offset:
repl_backlog_histlen:

slave

$ bin/redis-cli -h 10.93.21.21 -p
10.93.21.21:> info replication
# Replication
role:slave
master_host:10.93.21.21
master_port:
master_link_status:up
master_last_io_seconds_ago:
master_sync_in_progress:
slave_repl_offset:
slave_priority:
slave_read_only:
connected_slaves:
master_repl_offset:
repl_backlog_active:
repl_backlog_size:
repl_backlog_first_byte_offset:
repl_backlog_histlen:

2、配置sentinel集群

10.93.21.21:26379

10.93.21.21:26389

10.93.21.21:26399

启动所有的节点，只要监控同一个redis master，启动的话自动连接成集群

# sentinel注册的IP和端口
bind 10.93.21.21
port
# working目录
dir /home/data_monitor/redis-3.2./sentinel
# sentinel监控哪个主节点
sentinel monitor mymaster 10.93.21.21
# 主节点挂掉多长时间，判定为挂掉，开始failover
sentinel down-after-milliseconds mymaster
# failover交由几个sentinel执行
sentinel parallel-syncs mymaster
# failover多长时间没完成，超时失败
sentinel failover-timeout mymaster 

启动sentinel集群

bin/redis-sentinel conf/s26379.conf
bin/redis-sentinel conf/s26389.conf
bin/redis-sentinel conf/s26399.conf

3、jedis自动切换ip和端口

先解决依赖：pom.xml

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-redis</artifactId>
    <version>1.0.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>2.7.0</version>
    <type>jar</type>
    <scope>compile</scope>
</dependency>    

连接池代码

public class JedisPoolUtil {

    private static JedisSentinelPool pool = null;

    public static Properties getJedisProperties() {

        Properties config = new Properties();
        InputStream is = null;
        try {
            is = JedisPoolUtil.class.getClassLoader().getResourceAsStream("cacheConfig.properties");
            config.load(is);
        } catch (IOException e) {
            logger.error("", e);
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    logger.error("", e);
                }
            }
        }
        return config;
    }

    /**
     * 创建连接池
     *
     */
    private static void createJedisPool() {
        // 建立连接池配置参数
        JedisPoolConfig config = new JedisPoolConfig();
        Properties prop = getJedisProperties();
        // 设置最大连接数
        config.setMaxTotal(StringUtil.nullToInteger(prop.getProperty("MAX_ACTIVE")));
        // 设置最大阻塞时间，记住是毫秒数milliseconds
        config.setMaxWaitMillis(StringUtil.nullToInteger(prop.getProperty("MAX_WAIT")));
        // 设置空间连接
        config.setMaxIdle(StringUtil.nullToInteger(prop.getProperty("MAX_IDLE")));
        // jedis实例是否可用
        boolean borrow = prop.getProperty("TEST_ON_BORROW") == "false" ? false : true;
        config.setTestOnBorrow(borrow);
        // 创建连接池
//      pool = new JedisPool(config, prop.getProperty("ADDR"), StringUtil.nullToInteger(prop.getProperty("PORT")), StringUtil.nullToInteger(prop.getProperty("TIMEOUT")));// 线程数量限制，IP地址，端口，超时时间
        //获取redis密码
        String password = StringUtil.nullToString(prop.getProperty("PASSWORD"));

         String masterName = "mymaster";
        Set<String> sentinels = new HashSet<String>();
        sentinels.add("192.168.137.128:26379");
        sentinels.add("192.168.137.128:26380");
        sentinels.add("192.168.137.128:26381");
        pool = new JedisSentinelPool(masterName, sentinels, config);
    }

    /**
     * 在多线程环境同步初始化
     */
    private static synchronized void poolInit() {
        if (pool == null)
            createJedisPool();
    }

    /**
     * 获取一个jedis 对象
     *
     * @return
     */
    public static Jedis getJedis() {
        if (pool == null)
            poolInit();
        return pool.getResource();
    }

    /**
     * 释放一个连接
     *
     * @param jedis
     */
    public static void returnRes(Jedis jedis) {
        pool.returnResource(jedis);
    }

    /**
     * 销毁一个连接
     *
     * @param jedis
     */
    public static void returnBrokenRes(Jedis jedis) {
        pool.returnBrokenResource(jedis);
    }

    public static void main(String[] args){
        Jedis jedis=getJedis();

    }

}