SpringCloud 分布式 Session 共享同步

通常情况下，Tomcat、Jetty等Servlet容器，会默认将Session保存在内存中。如果是单个服务器实例的应用，将Session保存在服务器内存中是一个非常好的方案。但是这种方案有一个缺点，就是不利于扩展。

目前越来越多的应用采用分布式部署，用于实现高可用性和负载均衡等。那么问题来了，如果将同一个应用部署在多个服务器上通过负载均衡对外提供访问，如何实现Session共享？

实际上实现Session共享的方案很多，其中一种常用的就是使用Tomcat、Jetty等服务器提供的Session共享功能，将Session的内容统一存储在一个数据库（如MySQL）或缓存（如Redis）中。

下面我们将在springcloud微服务项目中，使用redis实现简单高效的session共享。官网：www.fhadmin.org

• eureka-server：注册中心

• springcloud-session-redis：业务session所在项目

• springcloud-session-zuul：路由网关

springcloud-session-redis项目

新建一个spring boot项目，命名springcloud-session-redis

pom

    4.0.0

    com.carry
    springcloud-session-redis
    0.0.1-SNAPSHOT
    jar

    springcloud-session-redis
    Demo project for Spring Boot

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.4.RELEASE
         
    

    
        UTF-8
        UTF-8
        1.8
        Finchley.SR1
    

    
        
            org.springframework.boot
            spring-boot-starter-data-redis
        
        
            org.springframework.session
            spring-session-data-redis
        
        
            org.apache.commons
            commons-pool2
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        

    

    
        
            
                org.springframework.cloud
                spring-cloud-dependencies
                ${spring-cloud.version}
                pom
                import
            
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

配置文件

在application.yml中加入redis、eureka、port等配

server:
  port: 8090
spring:
  application:
    name: service-session-redis
  redis:
    host: 192.168.68.100
    port: 6379
    password: 123456
    timeout: 6000ms
    lettuce:
      pool:
        max-active: 8
        max-wait: -1ms
        max-idle: 8
        min-idle: 0
    database: 0
eureka:
  client:
    serviceUrl:
      defaultZone: http://admin:123456@localhost:8761/eureka/
management: 
  endpoints:
    web:
      exposure: 
        include: "*"
      cors:
        allowed-origins: "*"
        allowed-methods: "*"

Redis Session配置类

package com.carry.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.session.data.redis.config.annotation.web.http.EnableRedisHttpSession;

@Configuration
@EnableRedisHttpSession
public class RedisSessionConfig {

}

控制层Controller中添加测试方法

package com.carry.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RefreshScope
public class UserManagementController {

    /**
     * redis sesion共享
     * 
     * @param request
     * @return
     */
    @GetMapping("/getUser")
    public String getUser(HttpServletRequest request) {
        HttpSession session = request.getSession();
        String username = (String) session.getAttribute("username");
        if (StringUtils.isEmpty(username)) {
            username = "testSessionRedis|" + System.currentTimeMillis();
            session.setAttribute("username", username);
        }
        System.out.println("访问端口：" + request.getServerPort());
        return username;
    }
}

springcloud-session-zuul项目

新建springboot项目，命名springcloud-session-zuul

POM依赖配置

    4.0.0

    com.carry
    springcloud-session-zuul
    0.0.1-SNAPSHOT
    jar

    springcloud-session-zuul
    Demo project for Spring Boot

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.4.RELEASE
         
    

    
        UTF-8
        UTF-8
        1.8
        Finchley.SR1
    

    
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client
        
        
            org.springframework.cloud
            spring-cloud-starter-netflix-zuul
        
    

    
        
            
                org.springframework.cloud
                spring-cloud-dependencies
                ${spring-cloud.version}
                pom
                import
            
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

配置文件

server:
  port: 1100
spring:
  application:
    name: service-session-zuul
zuul: 
  ignoredServices: '*' #忽略所有未配置的service
  host:
    connect-timeout-millis: 20000
    socket-timeout-millis: 20000
  routes:
    redis-session-service: 
      path: /user-session/**
      serviceId: service-session-redis
      sensitiveHeaders: "*" 
ribbon: #ribbon负载均衡参数配置
  ReadTimeout: 5000
  ConnectTimeout: 5000
eureka:
  client:
    serviceUrl:
      defaultZone: http://admin:123456@localhost:8761/eureka/

启动类

package com.carry;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@EnableEurekaClient
@SpringBootApplication
@EnableZuulProxy
public class SpringcloudSessionZuulApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringcloudSessionZuulApplication.class, args);
    }
}