<p dir="auto">It can be super helpful to piggyback on ElasticSearch's node stats endpoint to report various stats on all nodes on the cluster, however non-data nodes (data=false or client=true)  do not seem to have this enabled, and node stats return mostly empty for them.</p>
<p dir="auto">Using 0.90</p>
<p dir="auto">If a data node hasn't been searched on, the getOs().getMem() in the NodesStatsResponse for that node will be null. It appears as if an actual search request has to be issued against a node for that to be populated.</p>