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Redis主从复制和主从切换

Redis的主从复制功能可以实现读写分离,一个主可以挂载多个从.从服务器只能实现读不可写.当主服务器挂掉之后,无法切换到从服务器写. 通过Redis的Sentinel可以实现主从切换:当主服务器挂掉之后,自动将其中一个从服务器升级为主服务器


  1. 配置主从复制

    1. 建立从文件夹,譬如 /usr/local/slaves/下建立 6380 6381 两个文件夹(两个从服务器)

    2. 复制redis.conf到刚建立的两个文件夹中

    3. 修改redis.conf 中的

      1. port 6380

      2. slaveof 127.0.0.1 6379  ------ip表示主服务器的ip  端口表示主服务器端口

      3. 保存退出,另一个从服务器做同样修改,如果端口不是6380,修改断开即可,此处修改为6381

    4. 启动主服务器 redis-server redis.conf

    5. 进入从服务器文件夹,启动从服务器

    6. 查看主服务器信息:redis-cli -p 6379 info Replication,可以看到有两个从服务器

    7. redis-cli -p 6379 进去主服务器,存储数据 set key val

    8. 进入从服务器,redis-cli -p 6380 查看数据 get key  查看是否能取出数据

  2. 配置主从切换

    1. 新建文件 sentinel.conf

    2. 编辑文件

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      ####master  sentinel.conf
      ##sentinel实例之间的通讯端口
      port 26379
      ####sentinel需要监控的master信息:<mastername> <masterIP> <masterPort> <quorum>.
      ####<quorum>应该小于集群中slave的个数,只有当至少<quorum>个sentinel实例提交"master失效" 才会认为master为ODWON("客观"失效) .
      sentinel monitor mymaster 127.0.0.1 6381 1
      sentinel down-after-milliseconds mymaster 1000
      sentinel failover-timeout mymaster 180000
      sentinel parallel-syncs mymaster 1
    4. 其他两个文件只需要修改端口即可

    5. 启动redis-sentinel sentinel.conf &

  3. 通过java读写主从服务器

    1. 需要添加Spring配置和其他两个jar包

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      <properties>
          <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
          <springVersion>3.2.9.RELEASE</springVersion>
      </properties>
       
      <dependencies>
          <dependency>
              <groupId>org.apache.commons</groupId>
              <artifactId>commons-pool2</artifactId>
              <version>2.4.2</version>
          </dependency>
       
       
          <dependency>
              <groupId>org.springframework.data</groupId>
              <artifactId>spring-data-redis</artifactId>
              <version>1.6.0.RELEASE</version>
          </dependency>
       
          <dependency>
              <groupId>org.springframework</groupId>
              <artifactId>spring-context</artifactId>
              <version>${springVersion}</version>
          </dependency>
          <dependency>
              <groupId>org.springframework</groupId>
              <artifactId>spring-tx</artifactId>
              <version>${springVersion}</version>
          </dependency>
          <dependency>
              <groupId>org.springframework</groupId>
              <artifactId>spring-context-support</artifactId>
              <version>${springVersion}</version>
          </dependency>
          <dependency>
              <groupId>cglib</groupId>
              <artifactId>cglib-nodep</artifactId>
              <version>3.1</version>
          </dependency>
       
       
          <dependency>
              <groupId>org.apache.commons</groupId>
              <artifactId>commons-lang3</artifactId>
              <version>3.1</version>
          </dependency>
          <dependency>
              <groupId>com.alibaba</groupId>
              <artifactId>fastjson</artifactId>
              <version>1.2.5</version>
          </dependency>
          <dependency>
              <groupId>org.aspectj</groupId>
              <artifactId>aspectjweaver</artifactId>
              <version>1.8.2</version>
          </dependency>
       
          <dependency>
              <groupId>junit</groupId>
              <artifactId>junit</artifactId>
              <version>4.8</version>
              <scope>test</scope>
          </dependency>
          <dependency>
              <groupId>net.sf.ehcache</groupId>
              <artifactId>ehcache</artifactId>
              <version>2.7.5</version>
          </dependency>
          <dependency>
              <groupId>org.slf4j</groupId>
              <artifactId>slf4j-api</artifactId>
              <version>1.6.6</version>
          </dependency>
          <dependency>
              <groupId>redis.clients</groupId>
              <artifactId>jedis</artifactId>
              <version>2.4.2</version>
          </dependency>
          <dependency>
              <groupId>commons-pool</groupId>
              <artifactId>commons-pool</artifactId>
              <version>1.6</version>
          </dependency>
          <dependency>
              <groupId>commons-logging</groupId>
              <artifactId>commons-logging</artifactId>
              <version>1.1.1</version>
          </dependency>
          <dependency>
              <groupId>org.slf4j</groupId>
              <artifactId>slf4j-log4j12</artifactId>
              <version>1.7.10</version>
              <scope>test</scope>
          </dependency>
      </dependencies>
    3. Spring配置

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        <bean id="redisSentinelConfiguration" class="org.springframework.data.redis.connection.RedisSentinelConfiguration">
            <property name="master">
                <bean class="org.springframework.data.redis.connection.RedisNode">
                    <property name="name" value="mymaster"/>
                </bean>
            </property>
            <property name="sentinels">
                <set>
                    <bean class="org.springframework.data.redis.connection.RedisNode">
                        <constructor-arg name="host" value="127.0.0.1"></constructor-arg>
         
                        <constructor-arg name="port" value="26479"></constructor-arg>
                    </bean>
                    <bean class="org.springframework.data.redis.connection.RedisNode">
                        <constructor-arg name="host" value="127.0.0.1"></constructor-arg>
         
                        <constructor-arg name="port" value="26579"></constructor-arg>
                    </bean>
                </set>
            </property>
        </bean>
         
        <bean id="jeidsConnectionFactory"
         
              class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
         
            <constructor-arg ref="redisSentinelConfiguration"/>
         
        </bean>
         
         
        <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
            <property name="connectionFactory" ref="jeidsConnectionFactory"/>
        </bean>
    4. java测试

      1. ?
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        import org.junit.Before;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import org.springframework.dao.DataAccessException;
        import org.springframework.data.redis.connection.RedisConnection;
        import org.springframework.data.redis.core.RedisCallback;
        import org.springframework.data.redis.core.RedisTemplate;
         
        /**
         * Created by vincent on 15-10-13.
         */
        public class CommonTest {
         
            private ApplicationContext context ;
         
            private RedisTemplate redisTemplate;
            final String key ="key7";
         
            @Before
            public void init(){
                context = new ClassPathXmlApplicationContext("applicationContext.xml");
                redisTemplate= context.getBean("redisTemplate",RedisTemplate.class);
            }
         
            @Test
            public void test1(){
                redisTemplate.execute(new RedisCallback() {
                    @Override
                    public Long doInRedis(RedisConnection redisConnection) throws DataAccessException {
                         redisConnection.set(key.getBytes(),(System.currentTimeMillis()+"").getBytes());
                        return 1L;
                    }
                });
            }
         
            @Test
            public void  test2(){
                Object execute = redisTemplate.execute(new RedisCallback() {
                    @Override
                    public Object doInRedis(RedisConnection redisConnection) throws DataAccessException {
                        return redisConnection.get(key.getBytes());
                    }
                });
         
                System.out.println(new String((byte[])execute));
         
            }
        }

 

参考文档:

    http://redis.readthedocs.org/en/latest/topic/sentinel.html

(责任编辑:IT)