Known outbound IPs for whitelisting
It would be helpful to have some method of whitelisting traffic coming from an HDInsight cluster. Whether that is specifying IPs or simply being able to see IPs somewhere doesn't matter.
The cluster is scaled up and down routinely so having PIPs on the nodes isn't a great way to go. Adding a firewall or proxy with UDR could work but adds additional cost. Adding all region IPs open up a lot more than the security department is comfortable with.