The following features are shipped as part of HDP 2.2 HDFS, but are not supported:
NameNode Federation (HDFS-1052)
viewFS (HADOOP-7257)
The following Apache components are shipped as part of HDP 2.2 YARN, but are not supported:
Fair Scheduler
MapReduce Uber AM
MapReduce Eclipse Plug-in
YARN support for Docker on Windows
The following components are shipped as part of HDP 2.2 Spark, but not supported:
Spark Standalone
BlinkDB
GraphX