使用 Redis 来存储 Apache Tomcat 7 的 Session

使用  Redis 服务器来存储Session非常有优势。首先它是一个NOSQL数据，第二它很容易扩展使用。 This kind of setup would lead to a clear understanding of how  Redis can behave as cache as well as a session storing system. In order to do this the instructions are as follows :-

1. Download  Redis and build by the following commands (This includes downloading it too)

   wget http://download.redis.io/redis-stable.tar.gz
   tar xvzf redis-stable.tar.gz
   cd redis-stable
   make

2. Start  Redis using command( Redis Directory refers to the directory where  Redis is built)

   cd RedisDirectory/src
   ./redis-server --port 6379

3. Get the latest version of  Apache Tomcat 7
4. Download the latest version for  JEDIS (A Redis Java Client),  Tomcat Redis Session Manager (Redis-backed non-sticky session store for Apache Tomcat) and  Apache Commons Pool .
5. Copy all the above files into the lib folder of the  Apache Tomcat 7 installation directory.
6. Add the lines mentioned below in the context.xml of your  Apache Tomcat 7 (Or on the context block of server.xml if applicable).Edit the Configurations as your settings. In out case the port number to be configured is 6279.

   1	< Valve  className = "com.radiadesign.catalina.session.RedisSessionHandlerValve"  />

   2	< Manager  className = "com.radiadesign.catalina.session.RedisSessionManager"

   3	host = "localhost"  <!-- optional: defaults to "localhost" -->

   4	port="6379"  <!-- optional: defaults to "6379" -->

   5	database="0"  <!-- optional: defaults to "0" -->

   6	maxInactiveInterval="60"  <!-- optional: defaults to "60" (in seconds) -->  />

7. Now restart your  Apache Tomcat 7 normally and now you would see that the sessions are being created in the Redis Rather than on Tomcat.

Thats it. Now you have your  Apache Tomcat 7 storing all the sessions in  Redis and it also takes care about the different aspects of sessions.

web.xml中的配置是有效的，即使是context.xml总配置maxInactiveInterval默认60秒，只要web.xml中的sessionConfig配置30分钟，则session的失效时间还是30分钟。