Ok. I have written a test case that (if run enough) will reproduce it. Its an intermittent bug. I have raised an issue: https://github.com/elasticsearch/elasticsearch/issues/6435
-- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to elasticsearch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/0b666a91-2f49-4787-ba2f-fb33a8fc023e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.