Version1.0 (basic functions are done with Redis)

In order to get this work, we need to setup the linux system file
limits:
1. user open file limits:
http://posidev.com/blog/2009/06/04/set-ulimit-parameters-on-ubuntu/
2. global open file limits:

http://parijatmishra.wordpress.com/2008/09/10/linux-global-per-user-and-per-process-limits-on-number-of-file-descriptors/
http://redis4you.com/articles.php?id=014&name=redis