Redis主從復制和主從切換

jopen 9年前發布 | 17K 次閱讀 Redis NoSQL數據庫

Redis的主從復制功能可以實現讀寫分離，一個主可以掛載多個從．從服務器只能實現讀不可寫．當主服務器掛掉之后，無法切換到從服務器寫．通過Redis的Sentinel可以實現主從切換：當主服務器掛掉之后，自動將其中一個從服務器升級為主服務器。


  1. 配置主從復制

    1. 建立從文件夾，譬如 /usr/local/slaves/下建立　6380 6381 兩個文件夾（兩個從服務器）

    2. 復制redis.conf到剛建立的兩個文件夾中

    3. 修改redis.conf 中的

      1. port 6380

      2. slaveof 127.0.0.1 6379  ------ip表示主服務器的ｉｐ　　端口表示主服務器端口

      3. 保存退出，另一個從服務器做同樣修改，如果端口不是6380，修改斷開即可，此處修改為6381

    4. 啟動主服務器　redis-server redis.conf

    5. 進入從服務器文件夾，啟動從服務器

    6. 查看主服務器信息：redis-cli -p 6379 info Replication,可以看到有兩個從服務器

    7. redis-cli -p 6379 進去主服務器，存儲數據 set key val

    8. 進入從服務器，redis-cli -p 6380 查看數據 get key 　查看是否能取出數據

  2. 配置主從切換

    1. 新建文件 sentinel.conf

    2. 編輯文件 

    3. ####master  sentinel.conf
##sentinel實例之間的通訊端口
port 26379
####sentinel需要監控的master信息：<mastername> <masterIP> <masterPort> <quorum>.
####<quorum>應該小于集群中slave的個數,只有當至少<quorum>個sentinel實例提交"master失效" 才會認為master為ODWON("客觀"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. 其他兩個文件只需要修改端口即可

    5. 啟動redis-sentinel sentinel.conf &

  3. 通過java讀寫主從服務器

    1. 需要添加Spring配置和其他兩個ｊａｒ包 

    2. <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 

      1. <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測試 

      1. 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));

    }
}


參考文檔：

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



來自：http://my.oschina.net/vincentzhao/blog/516245

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