Heap Memory Not Used

Hi everyone,

I'm getting some slow performance with Elasticsearch, and I have noticed after some performance tweaking that the heap_used_percent is very low on each node (< 10%)

I'm pretty new to production Elasticsearch and trying to figure out what is causing my aggregations to take 4-7 seconds.

I'm running a 3 node cluster with 4G ram each, with max heap set to 2g on each node.

Thanks for any advice!
nathan