Redis+Tomcat+Nginx cluster realizes session sharing, Tomcat session sharing

Redis+Tomcat+Nginx cluster realizes session sharing, Tomcat session sharing

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Sweet Potato YaoNovember 27, 2017

http://fanshuyao.iteye.com/

1. Session sharing is implemented using the tomcat-cluster-redis-session-manager plugin

See the plugin address: https://github.com/ran-jit/tomcat-cluster-redis-session-manager

The plugin supports Tomcat7, Tomcat8, Tomcat9

Or download directly in the attachment (version 2.0.2, the latest version before 2017-11-27)

Here is one that only supports Tomcat7, not tomcat8, and there is no new maintenance for the time being:

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

2. Detailed explanation of tomcat-cluster-redis-session-manager

1. The decompressed files are as follows:

There is a redis-data-cache.properties in the conf directory: Redis configuration file

#-- Redis data-cache configuration

#- redis hosts ex: 127.0.0.1:6379, 127.0.0.2:6379, 127.0.0.2:6380, ....
redis.hosts=127.0.0.1:6379

#- redis password (for stand-alone mode)
#redis.password=

#- set true to enable redis cluster mode
redis.cluster.enabled=false

#- redis database (default 0)
#redis.database=0

#- redis connection timeout (default 2000)
#redis.timeout=2000

There are 4 jar packages in the lib directory, as follows:

commons-logging-1.2.jar

commons-pool2-2.4.2.jar

jedis-2.9.0.jar

tomcat-cluster-redis-session-manager-2.0.1.jar

3. How to use:

There is a usage method in the compressed file, see the readMe.txt file:

first step:

1. Move the downloaded jars to tomcat/lib directory
		* tomcat/lib/

Just copy all the Jar packages in the lib directory to the tomcat/lib directory

(Generally speaking, tomcat is a cluster, there are at least 2 tomcats, so configure a tomcat first, after copying the file, then copy the tomcat file again, which saves trouble, but you need to modify the corresponding port of tomcat)

Step 2:

2. Add tomcat system property "catalina.base"
		* catalina.base="TOMCAT_LOCATION"

It is to configure an environment variable, like the environment variable configured by Jdk, you need to configure an environment variable of catalina.base, the value is TOMCAT_LOCATION

as follows:

third step:

3. Extract downloaded package (tomcat-cluster-redis-session-manager.zip) to configure Redis credentials in redis-data-cache.properties file and move the file to tomcat/conf directory
		* tomcat/conf/redis-data-cache.properties

把conf目录下的配置文件redis-data-cache.properties复制到tomcat/conf/目录下

第四步：

4. Add the below two lines in tomcat/conf/context.xml
		<Valve className="tomcat.request.session.redis.SessionHandlerValve" />
		<Manager className="tomcat.request.session.redis.SessionManager" />

在tomcat/conf/目录下的context.xml文件，加上相应的配置，如下：

<?xml version="1.0" encoding="UTF-8"?>

<!--
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
--><!-- The contents of this file will be loaded for each web application --><Context>

    <!-- Default set of monitored resources. If one of these changes, the    -->
    <!-- web application will be reloaded.                                   -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->
	<Valve className="tomcat.request.session.redis.SessionHandlerValve"/>
	<Manager className="tomcat.request.session.redis.SessionManager"/>

</Context>

第五步：

5. Verify the session expiration time (minutes) in tomcat/conf/web.xml
		<session-config>
			<session-timeout>60<session-timeout>
		<session-config>

修改session的过期时间，默认是30分钟，可以不需要此步骤。

session集群的配置至此结束。

四、Nginx集群

1、下载Nignx：http://nginx.org/en/download.html

本人练习时使用windows，所以下载的windows版本：http://nginx.org/download/nginx-1.13.7.zip

2、下载后解压：D:\soft\nginx-1.12.2 （之前使用的是1.12.2的版本，现在最新版是1.13.7，但都一样，附件中有1.12.2版本提供下载）

3、修改Nginx配置文件nginx.conf

进入conf目录（D:\soft\nginx-1.12.2\conf），找到nginx.conf配置文件，打开编辑：

3.1在http{……}里加上upstream，如下：

upstream myTomcatCluster{# tomcatCluster和proxy_pass保持一样  
	    #解决session的问题  
	    #ip_hash;#加上这个，解决Session每次访问页面都不一样，加上就一样了。  
		  
	    #这里是tomcat的地址，weight越大，访问机率越大。  
	    server 127.0.0.1:9300 weight=1 fail_timeout=5s max_fails=1;  
	    server 127.0.0.1:9400 weight=1 fail_timeout=5s max_fails=1;  
    }

server：配置tomcat服务器请求的地址，2台Tomcat服务就配置2个server，分别对应9300，9400端口

weight 表示权重，权重越大，访问到的机率越大。

3.2、修改location / {……}

默认是这个的：

    Xml代码   
    
  
location / {  
            root   html;  
            index  index.html index.htm;  
        }  

修改成这样：

    Xml代码   
    
  
location / {  
            #root   html;  
        proxy_pass http://myTomcatCluster;  
            #index  index.html index.htm;  
        proxy_set_header Host $host;  
            proxy_set_header X-Real-IP $remote_addr;  
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;  
            proxy_connect_timeout       1;  
            proxy_read_timeout          1;  
            proxy_send_timeout          1;   
        }  

最简单的配置就是：

    Xml代码   
    
  
location / {  
     proxy_pass http://myTomcatCluster;  
}  

myTomcatCluster 对应upstream后的命名。

下面的配置可以解决2个Tomcat服务器集群，当一台服务器挂掉（宕机）后，请求变得很慢的问题。

（Tomcat集群一台服务器挂掉后请求变慢解决方案）

    Xml代码   
    
  
proxy_connect_timeout       1;  
proxy_read_timeout          1;  
proxy_send_timeout          1;   

3.3、启动Nginx服务器

使用Windows命令行启动

（1）进入D盘：d:

（2）进入D:\soft\nginx-1.12.2目录：

cd D:\soft\nginx-1.12.2

（3）启动服务：（启动一闪而过，但打开进程管理器能看到是已经启动的）

start nginx

关闭服务的命令：nginx -s stop

重新加载的命令：nginx -s reload，修改配置文件后，可以使用该命令直接加载，不需要重启。

五、测试集群：

1、tomcat准备

将已经配置好的一个tomcat复制一份，修改端口，然后再修改一下tomcat的配置文件（server.xml）

我的一个tomcat在：D:\soft\apache-tomcat-8.0.45-9300\conf

另一个是：D:\soft\apache-tomcat-8.0.45-9400\conf

修改：

<Engine defaultHost="localhost" name="Catalina">

其中tomcat 9300端口的修改如下：

<Engine defaultHost="localhost" jvmRoute="jvm9300" name="Catalina">

tomcat 9400端口的修改如下：

<Engine defaultHost="localhost" jvmRoute="jvm9400" name="Catalina">

2、项目准备：

新建立一个web项目，然后新建立一个index.jsp的文件，如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>首页redis-session</title>
</head>
<body>
	<div>tomcat 集群测试</div>
	<div>
		<%   
		  //HttpSession session = request.getSession(true);   
		  System.out.println(session.getId());   
		  out.println("<br> SESSION ID:" + session.getId()+"<br>");   
		%>
	</div>
</body>
</html>

主要是在打印页面输出sessionId的信息：

out.println("<br> SESSION ID:" + session.getId()+"<br>");

然后把这个项目分别部署到9300、9400端口的2个tomcat中，分别启动，记得也启动Nginx和redis哦

然后打开浏览器通过地址访问项目：http://localhost/redis-session/ （使用Nginx集群分发，不需要端口号访问），显示如下：

tomcat 集群测试

SESSION ID:B837ECA85B47081EAA2FEFCD7E579CD2.jvm9400

无论怎么刷新访问（打开新的标签页也是（非新窗口））的都是jvm9400，也就是端口号为9400的tomcat

后缀.jvm9400就是前面配置的：

<Engine defaultHost="localhost" jvmRoute="jvm9400" name="Catalina">

打开新的隐身窗口访问：

tomcat 集群测试

SESSION ID:83BBA58F4EB7B2EFF90AE05D4A0629FD.jvm9300

这时访问的是端口号为9300的tomcat，通过后缀.jvm9300判断知道。

新窗口每次访问的是都是tomcat9300，session也不会变。

在访问后缀为.jvm9400时，把端口9400的tomcat关掉，再次刷新访问，sessionId一样不变，由此可见，2个tomcat的sessionId是共享的。

使用Redis实现session共享的好处就是，把session管理放在redis中，如果服务器重启或挂机，sessionId保存在redis中，下次重启后一样生效，避免sessionId失效，同样redis最好也做集群，避免redis重启或挂机。

结束了。

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蕃薯耀 2017年11月27日

http://fanshuyao.iteye.com/

Redis+Tomcat+Nginx cluster realizes session sharing, Tomcat session sharing

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