Hi Andrew,
Thanks for your answer, I'll try to increase the client_inactivity_timeout to see if the error still occur. This settings looks promising !
I don't understand what you mean by "output only to stdout or to a file from LS?". Do you mean I should drop the elasticsearch output and replace it with a stdout output to test if the problem still occur ? Because since I get the error on the filebeat side, and nothing at all in logstash logs I doubt the elasticsearch output is the problem so I'm not sure I get your idea (my english is not very good). If the inactivity timeout has no effect, I will give it a try even if I'm not sure I understood correctly because it's easy to do.
I'll let you know the results, let me know if I get the second part of your message.
Thanks again !