基于nginx tomcat-redis-session-manager实现session共享

一、前言

nginx 作为目前最流行的开源反向代理HTTP Server，用于实现资源缓存、web server负载均衡等功能，由于其轻量级、高性能、高可靠等特点在互联网项目中有着非常普遍的应用，相关概念网上有丰富的介绍。分布式web server集群部署后需要实现session共享，针对 tomcat 服务器的实现方案多种多样，比如 tomcat cluster session 广播、nginx IP hash策略、nginx sticky module等方案，本文主要介绍了使用 redis 服务器进行 session 统一存储管理的共享方案。

相关应用结构参照下图：

二、环境配置

系统：Centos7 tomcat：apache-tomcat-7.0.78 redis：redis-2.8.9

三、构建 tomcat-redis-session-manager-master

1、由于源码构建基于 gradle，请先配置 gradle 环境。 2、从 github 获取 tomcat-redis-session-manager-master 源码，地址如下：

https://github.com/jcoleman/tomcat-redis-session-manager

3、找到源码中的 build.gradle 文件，由于作者使用了第三方仓库（sonatype），需要注册帐号，太麻烦，注释后直接使用maven中央仓库，同时注释签名相关脚本并增加依赖包的输出脚本 copyJars（dist目录），修改后的 build.gradle 文件如下：

apply plugin: 'java' apply plugin: 'maven' apply plugin: 'signing' group = 'com.orangefunction' version = '2.0.0' repositories { mavenCentral() } compileJava { sourceCompatibility = 1.7 targetCompatibility = 1.7 } dependencies { compile group: 'org.apache.tomcat', name: 'tomcat-catalina', version: '7.0.27' compile group: 'redis.clients', name: 'jedis', version: '2.5.2' compile group: 'org.apache.commons', name: 'commons-pool2', version: '2.2' //compile group: 'commons-codec', name: 'commons-codec', version: '1.9' testCompile group: 'junit', name: 'junit', version: '4.+' testCompile 'org.hamcrest:hamcrest-core:1.3' testCompile 'org.hamcrest:hamcrest-library:1.3' testCompile 'org.mockito:mockito-all:1.9.5' testCompile group: 'org.apache.tomcat', name: 'tomcat-coyote', version: '7.0.27' } task javadocJar(type: Jar, dependsOn: javadoc) { classifier = 'javadoc' from 'build/docs/javadoc' } task sourcesJar(type: Jar) { from sourceSets.main.allSource classifier = 'sources' } artifacts { archives jar archives javadocJar archives sourcesJar } //signing { // sign configurations.archives //} task copyJars(type: Copy) { from configurations.runtime into 'dist' } uploadArchives { repositories { mavenDeployer { beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) } //repository(url: "https://oss.sonatype.org/service/local/staging/deploy/maven2/") { // authentication(userName: sonatypeUsername, password: sonatypePassword) //} //repository(url: "https://oss.sonatype.org/content/repositories/snapshots") { // authentication(userName: sonatypeUsername, password: sonatypePassword) //} pom.project { name 'tomcat-redis-session-manager' packaging 'jar' description 'Tomcat Redis Session Manager is a Tomcat extension to store sessions in Redis' url 'https://github.com/jcoleman/tomcat-redis-session-manager' issueManagement { url 'https://github.com:jcoleman/tomcat-redis-session-manager/issues' system 'GitHub Issues' } scm { url 'https://github.com:jcoleman/tomcat-redis-session-manager' connection 'scm:git:git://github.com/jcoleman/tomcat-redis-session-manager.git' developerConnection 'scm:git:git@github.com:jcoleman/tomcat-redis-session-manager.git' } licenses { license { name 'MIT' url 'http://opensource.org/licenses/MIT' distribution 'repo' } } developers { developer { id 'jcoleman' name 'James Coleman' email 'jtc331@gmail.com' url 'https://github.com/jcoleman' } } } } } }

4、执行gradle命令构建源码，编译输出tomcat-redis-session-manager-master 及依赖jar包

gradle build -x test copyJars

文件列表如下：

四、tomcat 配置

两台tomcat服务器分别在不同的虚拟机上，地址：

http://192.168.31.84:8080 http://192.168.31.82:8080

五、编写测试页面

在tomcat安装目录下webapps/ROOT/添加test.jsp文件，内容为：

<%@ page contentType="text/html;charset=UTF-8" isELIgnored="false"%> SessionID:<%=session.getId()%><BR> SessionIP:<%=request.getServerName()%> <BR> SessionPort:<%=request.getServerPort()%> <% out.println("This is Tomcat Server 82（根据情况修改，以便区别） ！"); %>

六、tomcat session manager 配置

1.添加commons-pool2-2.2、jedis-2.5.2、tomcat-redis-session-manager-master-2.0.0jar包到tomcat 安装目录的 lib 文件夹； 2.修改两台tomcat的context.xml文件，使 tomcat-redis-session-manager-master 作为session管理器，同时指定redis地址和端口。

context.xml配置：

<Context> <WatchedResource>WEB-INF/web.xml</WatchedResource> <Valve className="com.orangefunction.tomcat.redissessions.RedisSessionHandlerValve" /> <Manager className="com.orangefunction.tomcat.redissessions.RedisSessionManager" host="192.168.31.84" port="6379" database="0" maxInactiveInterval="60" /> </Context>

3.重启两台tomcat

七、nginx 配置

1.修改nginx.conf文件，内容如下：

#user nobody; worker_processes 1; events { worker_connections 1024; } http { include mime.types; default_type application/octet-stream; sendfile on; keepalive_timeout 65; upstream tomcat_nginx { server localhost:8080; server 192.168.31.82:8080; } server { listen 80; server_name localhost; location / { proxy_pass http://tomcat_nginx; root html; index index.html index.htm; } error_page 500 502 503 504 /50x.html; location = /50x.html { root html; } } }

2.重启nginx：

nginx -s reload

八、测试

访问http://192.168.31.84/test.jsp，如下：

nginx默认采用轮询的方式进行负载均衡，刷新页面：

参考 http://www.cnblogs.com/lengfo/p/4260363.html