Redis tomcat
http://blog.csdn.net/fu9958/article/details/17325563
http://my.oschina.net/kolbe/blog/618167
http://blog.csdn.net/chszs/article/details/42610365
http://www.cnblogs.com/interdrp/p/4868740.html
https://github.com/jcoleman/tomcat-redis-session-manager