I have a few TBs of data in the logstash-* indexes. I also have
metricbeat-* and vdbench-* indexes that are a bit smaller. I don't see
any unusually high load on my elasticsearch cluster when I try to load a
Kibana page.
I will say that the logstash-* index does have a few thousand fields
defined in it. Seems like it might be related to that? The old version
didn't seem to care.