Once your HBase table is ready, it’s time to map a table in Phoenix to your data in HBase. You use a JDBC connection to access Phoenix, and there are two drivers included on your cluster under /usr/lib/phoenix/bin. First, the Phoenix client connects directly to HBase processes to execute queries, which requires several ports to be open in your Amazon EC2 Security Group (for ZooKeeper, HBase Master, and RegionServers on your cluster) if your client is off-cluster.
Second, the Phoenix thin client connects to the Phoenix Query Server, which runs on port 8765 on the master node of your EMR cluster. This allows you to use a local client without adjusting your Amazon EC2 Security Groups by creating a SSH tunnel to the master node and using port forwarding for port 8765. The Phoenix Query Server is still a new component, and not all SQL clients can support the Phoenix thin client.
I am not HBase’s biggest fan, but I do think that Phoenix fixes one of the biggest problems HBase has: its being completely foreign to most data professionals. It’s not an accident that as a data platform matures, its development language looks more and more like SQL.