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:[e-mail]: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 '[e-mail]'            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://192.168.31.84:8080http://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