We have an ES (version 1.2.4) cluster with 5 nodes. During stress tests on the cluster I notice that one node is using much more (33-50%) heap space and cpu than the other nodes. Eventually this node uses almost all heap space causing slow queries while other nodes should still be fine.
As we use a load balancer in front of ES, all requests are spread evenly across the nodes (checked with access logs).
Has anyone seen such behaviour before, or could you maybe point me in the right direction in what to investigate?