【Redis】Redis主从实现读写分离

淡淡的烟草味﹌ 2022-06-15 03:40 199阅读 0赞

前言   
大家在工作中可能会遇到这样的需求，即Redis读写分离，目的是为了压力分散化。下面我将为大家介绍借助AWS的ELB实现读写分离，以写主读从为例。

实现   
引用库文件

<dependency>
     <groupId>redis.clients</groupId>
     <artifactId>jedis</artifactId>
     <version>2.6.2</version>
    </dependency>

方式一，借助切面

JedisPoolSelector

此类的目的是为读和写分别配置不同的注解，用来区分是主还是从。

package com.silence.spring.redis.readwriteseparation;
    
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    /** * Created by keysilence on 16/10/26. */
    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.METHOD)
    public @interface JedisPoolSelector {
    
      String value();
    
    }

JedisPoolAspect   
此类的目的是针对主和从的注解，进行动态链接池调配，即主的使用主链接池，从的使用从连接池。

package com.silence.spring.redis.readwriteseparation;
    
    import org.aspectj.lang.JoinPoint;
    import org.aspectj.lang.annotation.Aspect;
    import org.aspectj.lang.annotation.Before;
    import org.aspectj.lang.annotation.Pointcut;
    import org.aspectj.lang.reflect.MethodSignature;
    import org.springframework.beans.BeansException;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.ApplicationContextAware;
    import redis.clients.jedis.JedisPool;
    
    import javax.annotation.PostConstruct;
    import java.lang.reflect.Method;
    import java.util.Date;
    
    /** * Created by keysilence on 16/10/26. */
    @Aspect
    public class JedisPoolAspect implements ApplicationContextAware {
    
      private ApplicationContext ctx;
    
      @PostConstruct
      public void init() {
        System.out.println("jedis pool aspectj started @" + new Date());
      }
    
      @Pointcut("execution(* com.silence.spring.redis.readwriteseparation.util.*.*(..))")
      private void allMethod() {
    
      }
    
      @Before("allMethod()")
      public void before(JoinPoint point)
      {
        Object target = point.getTarget();
        String method = point.getSignature().getName();
    
        Class classz = target.getClass();
    
        Class<?>[] parameterTypes = ((MethodSignature) point.getSignature())
            .getMethod().getParameterTypes();
        try {
          Method m = classz.getMethod(method, parameterTypes);
          if (m != null && m.isAnnotationPresent(JedisPoolSelector.class)) {
            JedisPoolSelector data = m
                .getAnnotation(JedisPoolSelector.class);
            JedisPool jedisPool = (JedisPool) ctx.getBean(data.value());
            DynamicJedisPoolHolder.putJedisPool(jedisPool);
          }
    
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    
      public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.ctx = applicationContext;
      }
    
    }

DynamicJedisPoolHolder   
此类目的是存储当前使用的JedisPool，即上面类赋值后的结果保存。

package com.silence.spring.redis.readwriteseparation;
    
    import redis.clients.jedis.JedisPool;
    
    /** * Created by keysilence on 16/10/26. */
    public class DynamicJedisPoolHolder {
    
      public static final ThreadLocal<JedisPool> holder = new ThreadLocal<JedisPool>();
    
      public static void putJedisPool(JedisPool jedisPool) {
        holder.set(jedisPool);
      }
    
      public static JedisPool getJedisPool() {
        return holder.get();
      }
    
    }

RedisUtils   
此类目的是对Redis具体的调用，里面包含使用主还是从的方式调用。

package com.silence.spring.redis.readwriteseparation.util;
    
    import com.silence.spring.redis.readwriteseparation.DynamicJedisPoolHolder;
    import com.silence.spring.redis.readwriteseparation.JedisPoolSelector;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    /** * Created by keysilence on 16/10/26. */
    public class RedisUtils {
      private static Logger logger = LoggerFactory.getLogger(RedisUtils.class);
    
      @JedisPoolSelector("master")
      public String setString(final String key, final String value) {
    
        String ret = DynamicJedisPoolHolder.getJedisPool().getResource().set(key, value);
        System.out.println("key:" + key + ",value:" + value + ",ret:" + ret);
    
        return ret;
      }
    
      @JedisPoolSelector("slave")
      public String get(final String key) {
    
        String ret = DynamicJedisPoolHolder.getJedisPool().getResource().get(key);
        System.out.println("key:" + key + ",ret:" + ret);
    
        return ret;
      }
    
    }

spring-datasource.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    
      <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        
        <property name="maxTotal" value="100"/>
        
        <property name="maxIdle" value="50"/>
        
        <property name="minIdle" value="20"/>
        
        <property name="maxWaitMillis" value="1000"/>
        
        
        <property name="testOnBorrow" value="true" />
        
        <property name="testOnReturn" value="true" />
        
        <property name="testWhileIdle" value="true" />
        
        <property name="numTestsPerEvictionRun" value="10" />
        
        <property name="timeBetweenEvictionRunsMillis" value="60000" />
        
        
      </bean>
    
      <bean id="master" class="redis.clients.jedis.JedisPool">
        <constructor-arg index="0" ref="poolConfig"/>
        <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/>
        <constructor-arg index="2" value="6379" type="int"/>
      </bean>
    
      <bean id="slave" class="redis.clients.jedis.JedisPool">
        <constructor-arg index="0" ref="poolConfig"/>
        
        <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/>
        <constructor-arg index="2" value="6380" type="int"/>
      </bean>
    
      <bean id="redisUtils" class="com.silence.spring.redis.readwriteseparation.util.RedisUtils">
      </bean>
    
      <bean id="jedisPoolAspect" class="com.silence.spring.redis.readwriteseparation.JedisPoolAspect" />
    
      <aop:aspectj-autoproxy proxy-target-class="true"/>
    
    </beans>

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Test

package com.silence.spring.redis.readwriteseparation;
    
    import com.silence.spring.redis.readwriteseparation.util.RedisUtils;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    /** * Created by keysilence on 16/10/26. */
    public class Test {
    
      public static void main(String[] args) {
    
        ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-datasource.xml");
    
        System.out.println(ctx);
    
        RedisUtils redisUtils = (RedisUtils) ctx.getBean("redisUtils");
        redisUtils.setString("aaa", "111");
    
        System.out.println(redisUtils.get("aaa"));
      }
    
    }

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方式二，依赖注入

与方式一类似，但是需要写死具体使用主的池还是从的池，思路如下：   
放弃注解的方式，直接将主和从的两个链接池注入到具体实现类中。

RedisUtils

package com.silence.spring.redis.readwriteseparation.util;
    
    import com.silence.spring.redis.readwriteseparation.DynamicJedisPoolHolder;
    import com.silence.spring.redis.readwriteseparation.JedisPoolSelector;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import redis.clients.jedis.JedisPool;
    
    /** * Created by keysilence on 16/10/26. */
    public class RedisUtils {
      private static Logger logger = LoggerFactory.getLogger(RedisUtils.class);
    
      private JedisPool masterJedisPool;
    
      private JedisPool slaveJedisPool;
    
      public void setMasterJedisPool(JedisPool masterJedisPool) {
        this.masterJedisPool = masterJedisPool;
      }
    
      public void setSlaveJedisPool(JedisPool slaveJedisPool) {
        this.slaveJedisPool = slaveJedisPool;
      }
    
      public String setString(final String key, final String value) {
    
        String ret = masterJedisPool.getResource().set(key, value);
        System.out.println("key:" + key + ",value:" + value + ",ret:" + ret);
    
        return ret;
      }
    
      public String get(final String key) {
    
        String ret = slaveJedisPool.getResource().get(key);
        System.out.println("key:" + key + ",ret:" + ret);
    
        return ret;
      }
    
    }

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spring-datasource.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    
      <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        
        <property name="maxTotal" value="100"/>
        
        <property name="maxIdle" value="50"/>
        
        <property name="minIdle" value="20"/>
        
        <property name="maxWaitMillis" value="1000"/>
        
        
        <property name="testOnBorrow" value="true" />
        
        <property name="testOnReturn" value="true" />
        
        <property name="testWhileIdle" value="true" />
        
        <property name="numTestsPerEvictionRun" value="10" />
        
        <property name="timeBetweenEvictionRunsMillis" value="60000" />
        
        
      </bean>
    
      <bean id="masterJedisPool" class="redis.clients.jedis.JedisPool">
        <constructor-arg index="0" ref="poolConfig"/>
        <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/>
        <constructor-arg index="2" value="6379" type="int"/>
      </bean>
    
      <bean id="slaveJedisPool" class="redis.clients.jedis.JedisPool">
        <constructor-arg index="0" ref="poolConfig"/>
        <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/>
        <constructor-arg index="2" value="6380" type="int"/>
      </bean>
    
      <bean id="redisUtils" class="com.silence.spring.redis.readwriteseparation.util.RedisUtils">
        <property name="masterJedisPool" ref="masterJedisPool"/>
        <property name="slaveJedisPool" ref="slaveJedisPool"/>
      </bean>
    
    </beans>

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