ZooKeeper session expiration happens when the client (HBase RegionServer) fails to successfully contact the ZooKeeper server. This can happen for a variety of reasons: JVM GC Pauses in the RegionServer Swapping of pages in memory to disk (instead of remaining in memory) Network partitions -- the RS host is physically unable to send traffic to the ZK host ZooKeeper connection rate-limiting https://community.hortonworks.com/articles/51191/understanding-apache-zookeeper-connection-rate-lim.html Typically, JVM GC pauses and swapping are the most common causes. Make sure that you have adequate memory on your system and configured for the RegionServer. The article linked for ZK connection rate-limiting has instructions to check if that is happening on your system. If you are a Hortonworks customer, please consider using SmartSense to help automatically diagnose some of these issues. ... View more

@Anas A @sbhat is correct. I would like to add to her response that HDP stack is 100% open source based on Apache. It is a tested platform as such tools from the ecosystem can work together and deliver enterprise level quality. Taking the tools from Apache does not assure that they will work smoothly together. There is no concept of license associated with HDP. You can use the distribution as-is, however, enterprises elect to purchase paid support as such that can receive 24x7 support and get the chance to influence the roadmap or receive special attention on critical issues. Hortonworks engineers are actively involved in Hadoop ecosystem tools development and they can help with addressing bugs or including features that the community would like to have added. Best for you would be to start with downloading the sandbox as @sbhat suggested. Good luck! ... View more