Tomcat + Memcached实现session共享

Linux Memcached安装

Linux系统安装memcached，要先安装libevent库。

yum install libevent libevent-devel

下载http://memcached.org，并上传解压缩

#解压缩
tar -zxvf memcached-1.6.6.tar.gz
#进入目录
cd memcached-1.6.6
#配置
./configure --prefix=/usr/local/memcached-1.6.6
#编译并安装
make && make install

Memcached运行

#帮助命令
/usr/local/memcached-1.6.6/bin/memcached -h

启动选项：

• -d是启动一个守护进程；
• -m是分配给Memcache使用的内存数量，单位是MB；
• -u是运行Memcache的用户；
• -l是监听的服务器IP地址，可以有多个地址；
• -p是设置Memcache监听的端口，，最好是1024以上的端口；
• -c是最大运行的并发连接数，默认是1024；
• -P是设置保存Memcache的pid文件。

作为后台服务程序运行

/usr/local/memcached-1.6.6/bin/memcached -p 11211 -m 64m -d

或者

/usr/local/memcached-1.6.6/bin/memcached -d -m 64M -u root -l 192.168.0.200 -p 11211 -c 256 -P /tmp/memcached.pid

Nginx配置

upstream tomcat{
	server 192.168.2.52:8080;
	server 192.168.2.53:8080;
}

location /tomcat {
	proxy_pass http://tomcat/;
} 

Tomcat配置

1.每个tomcat的context.xml中加入

<Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager" 
	memcachedNodes="n1:192.168.71.100:11211" 
    sticky="false" 
    lockingMode="auto"
    sessionBackupAsync="false"
	requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js)$"
    sessionBackupTimeout="1000" transcoderFactoryClass="de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory" 
/>

2.到tomcat的lib目录下，添加jar包

链接：https://github.com/magro/memcached-session-manager/wiki/SetupAndConfiguration#add-custom-serializers-to-your-webapp-optional

此处以tomcat8为例

<!-- memcached-session-manager-tc8 依赖 memcached-session-manager  -->
<dependency>
    <groupId>de.javakaffee.msm</groupId>
    <artifactId>memcached-session-manager-tc8</artifactId>
    <version>2.3.2</version>
</dependency>
<!-- memcached-session-manager 依赖 spymemcached-->
<dependency>
    <groupId>de.javakaffee.msm</groupId>
    <artifactId>memcached-session-manager</artifactId>
    <version>2.3.2</version>
</dependency>
<dependency>
    <groupId>net.spy</groupId>
    <artifactId>spymemcached</artifactId>
    <version>2.12.0</version>
</dependency>

<!-- msm-kryo-serializer 依赖 kryo-serializers、 kryo-serializers -->
<dependency>
    <groupId>de.javakaffee.msm</groupId>
    <artifactId>msm-kryo-serializer</artifactId>
    <version>2.3.2</version>
</dependency>

<dependency>
    <groupId>de.javakaffee</groupId>
    <artifactId>kryo-serializers</artifactId>
    <version>0.41</version>
</dependency>
<!-- kryo 依赖minlog、reflectasm、objenesis -->
<dependency>
    <groupId>com.esotericsoftware</groupId>
    <artifactId>kryo</artifactId>
    <version>4.0.0</version>
</dependency>
<dependency>
    <groupId>com.esotericsoftware</groupId>
    <artifactId>minlog</artifactId>
    <version>1.3.0</version>
</dependency>
<dependency><!-- tomcat7不需要这个包？？？ -->
    <groupId>org.objenesis</groupId>
    <artifactId>objenesis</artifactId>
    <version>2.2</version>
</dependency>
<!--reflectasm 依赖 asm -->
<dependency>
    <groupId>com.esotericsoftware</groupId>
    <artifactId>reflectasm</artifactId>
    <version>1.11.3</version>
</dependency>
<dependency>
    <groupId>org.ow2.asm</groupId>
    <artifactId>asm</artifactId>
    <version>5.0.4</version>
</dependency>

3.在每个tomcat的webapps/Root目录下修改index.html，加入如下代码

<h1>server-02</h1><% out.print( session.getId()); %>