http://www.ylzx8.cn/zonghe/open-source/250335.html
http://www.hankcs.com/program/java/lucene-4-6-1-java-lang-illegalstateexception-tokenstream-contract-violation.html
http://hellotommy.iteye.com/blog/826333
http://blog.sematext.com/2013/07/01/recipe-rsyslog-elasticsearch-kibana/