This isn’t something I will notice again now that I’ve got my heap space sorted … but when you are using Kibana to add index patterns, there’s nothing that waits until you’ve stopped typing for x seconds or implements a minimum characters before searching. So, after each character you type into the dialog, a search is performed against the ES server — here I wanted to create a pattern for logstash-* — which sent nine different search requests to my ES. And, if the server is operating reasonably, all of these searches would deliver a result set that Kibana essentially ignores as I’m tying more characters. But, in my case, the ES server fell over before I could even type logstash!