+1 definitely upgrade to 2.1.16. You shouldn't see any compatibility issues
client side when upgrading from 2.1.0. If scrub removed 500 SSTables that's
quite worrying. If the mass SSTables are causing issues you can disconnect
the node from the cluster using:
nodetool disablegossip && nodetool disablebinary && nodetool disablethrift
This will give it a chance to compact SSTables while not impacting read
performance. To be on the safe side you shouldn't have it disconnected for
longer than 3 hours (default hinted handoff window). You can re-enable it
with:
nodetool enablegossip && nodetool enablebinary && nodetool enablethrift
