常用的像微软的网络负载平衡NLB、甲骨文的Oracle RAC、思科的负载均衡(SLB)，Apach+Tomcat 负载均衡
http://www.cnblogs.com/mokafamily/p/4402366.html
http://kb.cnblogs.com/page/73735/
http://www.cnblogs.com/yeyublog/p/6438373.html
