You are playing from the old playbook though. Heck, we have HA NameNode setups and name node clusters now, and some implementations of Hadoop don't even use HDF

You are playing from the old playbook though. Heck, we have HA NameNode setups and name node clusters now, and some implementations of Hadoop don't even use HDFS. The Hadoop's tech stack has changed a lot over the years. It's much different now. It's worth noting that there are many examples now of clusters with five figures worth of nodes.