In my initial ignorance and enthusiasm, I installed nxlog on a load of servers and started pumping Windows events into my Elasticsearch/Kibana/Fluentd box. I wasn't aware quite how many different fields would build up, and I had an index with about 600 fields before long; needless to say, the box ground to a halt.
I deleted the data, and placed nxlog on just a couple of domain controllers - now I have 11 fields, and life looks much better. Unfortunately when I go to 'Discover' and select the index pattern from the drop-down list, it sits there "searching" endlessly. I had previously deleted and recreated that index.
I would appreciate any recommendations on where to start debugging this, as I'm still a bit green with Kibana.