sudo hdfs dfsadmin -report                           
report: Call From ip-172-31-57-152.ec2.internal/172.31.57.152 to ip-172-31-57-15
2.ec2.internal:8020 failed on connection exception: java.net.ConnectException: C
onnection refused; For more details see:  http://wiki.apache.org/hadoop/Connecti
onRefused