I enabled the shard query cache on my indices and gave a bit more of the heap to this sort of cache in an Elasticsearch 1.7.1 cluster. When I repeatedly run a Kibana dashboard with lots of
terms aggregations and line charts with
date histogram aggregation with
unique count on this cluster I expected to have many hits on this cache, at least when I use a timespan of
last 7 days.
Instead Elasticsearch shows me about 80 hits and 12000 misses per node (I just had the nodes restarted).
This sort of cache should store all
countresults per shard, so when I query old shards I expect lots of hits. Did I misunderstand the shard query cache?