https://issues.apache.org/jira/browse/SOLR-1395
http://my.oschina.net/zhzhenqin/blog/83746
Solrcloud
http://my.oschina.net/zhzhenqin/blog/84995
http://www.cnblogs.com/phinecos/archive/2012/02/10/2345634.html
http://www.chepoo.com/solrcloud-introduction.html