With all the new features provided in Streams 3.1, we are considering to upgrade our current version of Streams from 3.0 to 3.1. Recently we tested the installation of Streams 3.1 on a cluster of CentOS 6 nodes. The installation of Streams 3.1 (on all nodes) and the Streams Studio (only on the head node) was successful. I was able to create and start an instance across multiple hosts successfully, but after a few seconds the "hc" (host controller service) services on all nodes failed except for the one on the head node, then the instance became "partially failed". Then I was able to use the new feature provided in the Streams 3.1 Web Consel to repair the intance sucessfully, but after a while, those "hc" on all child nodes failed again, all these happend when I didn't even submit any jobs to the instance. It seems that all the services running on the head node were all fine. We didn't have such a problem when using Streams 3.0 on a cluster. Anyone could provide us any clue what could cause the problem? or anything we need to adjust in Streams 3.1? Attached is the logs for the instance that I downloaded from the Streams Console, we really hope anyone here could help us out. Thanks!!