We have FluentD sending logs to elastic search, and we have installed x-pack on Kibana and elastic search. everything works fine and after some time we stop seeing logs in ? what can we check. we have 5.1.2 and 5.1.2 version of Elastic and Kibana. is there anything i can check or see as i don't see anything in the logs neither in kibana/elastic/fluentD. Any help is appreciated here. we will be getting our x-pack licensed soon but our POC needs to be verified and approved. Not sure what is wrong where. Can anyone help or suggest me anything?