Redis主從實現讀寫分離

2020-10-28 21:38:42

字體：大中小

來源：轉載

供稿：網友

前言

大家在工作中可能會遇到這樣的需求，即Redis讀寫分離，目的是為了壓力分散化。下面我將為大家介紹借助AWS的ELB實現讀寫分離，以寫主讀從為例。

實現

引用庫文件

  <!-- redis客戶端 -->  <dependency>   <groupId>redis.clients</groupId>   <artifactId>jedis</artifactId>   <version>2.6.2</version>  </dependency>

方式一，借助切面

JedisPoolSelector

此類的目的是為讀和寫分別配置不同的注解，用來區分是主還是從。

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

此類的目的是針對主和從的注解，進行動態鏈接池調配，即主的使用主鏈接池，從的使用從連接池。

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. */@Aspectpublic 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

此類目的是存儲當前使用的JedisPool，即上面類賦值后的結果保存。

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

此類目的是對Redis具體的調用，里面包含使用主還是從的方式調用。

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">    <!-- 池中最大鏈接數 -->    <property name="maxTotal" value="100"/>    <!-- 池中最大空閑鏈接數 -->    <property name="maxIdle" value="50"/>    <!-- 池中最小空閑鏈接數 -->    <property name="minIdle" value="20"/>    <!-- 當池中鏈接耗盡，調用者最大阻塞時間，超出此時間將跑出異常。（單位：毫秒；默認為-1，表示永不超時） -->    <property name="maxWaitMillis" value="1000"/>    <!-- 參考：http://biasedbit.com/redis-jedispool-configuration/ -->    <!-- 調用者獲取鏈接時，是否檢測當前鏈接有效性。無效則從鏈接池中移除，并嘗試繼續獲取。（默認為false） -->    <property name="testOnBorrow" value="true" />    <!-- 向鏈接池中歸還鏈接時，是否檢測鏈接有效性。（默認為false） -->    <property name="testOnReturn" value="true" />    <!-- 調用者獲取鏈接時，是否檢測空閑超時。如果超時，則會被移除（默認為false） -->    <property name="testWhileIdle" value="true" />    <!-- 空閑鏈接檢測線程一次運行檢測多少條鏈接 -->    <property name="numTestsPerEvictionRun" value="10" />    <!-- 空閑鏈接檢測線程檢測周期。如果為負值，表示不運行檢測線程。（單位：毫秒，默認為-1） -->    <property name="timeBetweenEvictionRunsMillis" value="60000" />    <!-- 鏈接獲取方式。隊列：false；棧：true -->    <!--<property name="lifo" value="false" />-->  </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"/>    <!-- 此處Host配置成ELB地址 -->    <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>

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"));  }}

方式二，依賴注入

與方式一類似，但是需要寫死具體使用主的池還是從的池，思路如下：
放棄注解的方式，直接將主和從的兩個鏈接池注入到具體實現類中。

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;  }}

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">    <!-- 池中最大鏈接數 -->    <property name="maxTotal" value="100"/>    <!-- 池中最大空閑鏈接數 -->    <property name="maxIdle" value="50"/>    <!-- 池中最小空閑鏈接數 -->    <property name="minIdle" value="20"/>    <!-- 當池中鏈接耗盡，調用者最大阻塞時間，超出此時間將跑出異常。（單位：毫秒；默認為-1，表示永不超時） -->    <property name="maxWaitMillis" value="1000"/>    <!-- 參考：http://biasedbit.com/redis-jedispool-configuration/ -->    <!-- 調用者獲取鏈接時，是否檢測當前鏈接有效性。無效則從鏈接池中移除，并嘗試繼續獲取。（默認為false） -->    <property name="testOnBorrow" value="true" />    <!-- 向鏈接池中歸還鏈接時，是否檢測鏈接有效性。（默認為false） -->    <property name="testOnReturn" value="true" />    <!-- 調用者獲取鏈接時，是否檢測空閑超時。如果超時，則會被移除（默認為false） -->    <property name="testWhileIdle" value="true" />    <!-- 空閑鏈接檢測線程一次運行檢測多少條鏈接 -->    <property name="numTestsPerEvictionRun" value="10" />    <!-- 空閑鏈接檢測線程檢測周期。如果為負值，表示不運行檢測線程。（單位：毫秒，默認為-1） -->    <property name="timeBetweenEvictionRunsMillis" value="60000" />    <!-- 鏈接獲取方式。隊列：false；棧：true -->    <!--<property name="lifo" value="false" />-->  </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>

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。

上一篇：Windows下Redis安裝配置教程

下一篇：redis實現簡單隊列