redis http://charsyam.wordpress.com/2011/11/06/redis%EC%97%90-%EC%8B%AC%ED%94%8C%ED%95%9C-key-value-%EB%A1%9C-%EC%88%98-%EC%96%B5%EA%B0%9C%EC%9D%98-%EB%8D%B0%EC%9D%B4%ED%84%B0-%EC%A0%80%EC%9E%A5%ED%95%98%EA%B8%B0/