这是分布式集群环境下，如何实现session共享系列的第五篇。在上一篇：分布式集群环境下，如何实现session共享四（部署项目测试）中，针对nginx不同的负载均衡策略：轮询、ip_hash方式，测试了session的不同使用情况，并且留下了一个问题：有没有可能针对nginx负载均衡策略（轮询）的基础上，对session实现共享呢？？？
本篇在nginx负载均衡策略（轮询的基础上），通过spring-session将session存储到redis，实现session共享。
1.改造项目
1.1.导入依赖
<!--spring 版本-->
<spring.version>5.0.2.RELEASE</spring.version>
<spring.session.data.redis.version>1.3.1.RELEASE</spring.session.data.redis.version>
<lettuce.version>3.5.0.Final</lettuce.version> <!-- spring web包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency> <dependency>
<groupId>org.springframework.session</groupId>
<artifactId>spring-session-data-redis</artifactId>
<version>${spring.session.data.redis.version}</version>
</dependency>
<dependency>
<groupId>biz.paluch.redis</groupId>
<artifactId>lettuce</artifactId>
<version>${lettuce.version}</version>
</dependency>
1.2.编写redis配置文件
redis.host=192.168.80.22
redis.pass=myredis
redis.port=6379
redis.session.timeout=600
1.3.编写spring配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd"> <context:annotation-config /> <!-- 加载properties文件 -->
<bean id="configProperties"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:session-redis.properties</value>
</list>
</property>
</bean> <!-- RedisHttpSessionConfiguration -->
<bean class="org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration">
<!-- session过期时间,单位是秒 -->
<property name="maxInactiveIntervalInSeconds" value="${redis.session.timeout}" />
</bean> <!--LettuceConnectionFactory -->
<bean class="org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory"
p:host-name="${redis.host}" p:port="${redis.port}" /> </beans>
1.4.配置web.xml
<!--加载spring配置文件-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:applicationContext-session.xml</param-value>
</context-param> <!--配置监听器-->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener> <!--配置过滤器（该过滤器要配置在第一的位置）-->
<filter>
<filter-name>springSessionRepositoryFilter</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter> <filter-mapping>
<filter-name>springSessionRepositoryFilter</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>REQUEST</dispatcher>
<dispatcher>ERROR</dispatcher>
</filter-mapping>
1.5.启动redis
#启动redis服务端
[root@hadoop02 bin]# ./redis-server #客户端连接操作
[root@hadoop02 bin]# ./redis-cli
#设置允许远程访问
127.0.0.1:6379> CONFIG SET protected-mode no
OK
2.nginx配置
#添加tomcat列表，真实应用服务器都放在这
upstream tomcat_pool{
#server tomcat地址:端口号 weight表示权值，权值越大，被分配的几率越大;
server 192.168.80.22:8080 weight=4 max_fails=2 fail_timeout=30s;
server 192.168.80.22:8081 weight=4 max_fails=2 fail_timeout=30s; }
3.测试
http://192.168.80.22/session-redis-demo/
3.1.谷歌浏览器测试
3.2.火狐浏览器测试
3.3.查看redis中存储的session
[root@hadoop02 bin]# ./redis-cli
127.0.0.1:6379> keys *
1) "spring:session:expirations:1558614360000"
2) "spring:session:sessions:af12f7a7-3385-44dc-93b2-a3fa82026b25"
3) "spring:session:sessions:abc97363-8f1d-4d1c-a9df-e2a78628af05"
4) "site"
5) "spring:session:sessions:expires:abc97363-8f1d-4d1c-a9df-e2a78628af05"
127.0.0.1:6379>
总结：通过spring-session把session存储到redis中，即便nginx负载均衡策略为轮询方式，也一样实现了session的共享，这才是我们的终极目标，真好！！！