https://community.cloudera.com/t5/Support-Questions/Docker-sandbox-hdp-hortonworks-com-50070-Connection-refused/m-p/176950#M139200 <P><A rel="user" href="https://community.cloudera.com/users/52155/timroberts.html" nodeid="52155">@Tim Roberts</A></P><P>Looks like in your case the HDFS Service check is failing because the HDFS service might not be healthy.</P><P>So please check the ambari UI --&gt; HDFS --&gt; "Service Actions" and then restart the HDFS services again then validate if the port 50070 is opened successfully or not?</P><PRE># netstat -tnlpa | grep 50070 (OR) # netstat -tnlpa | grep `cat /var/run/hadoop/hdfs/hadoop-hdfs-namenode.pid`</PRE><P>.</P> Thu, 21 Dec 2017 07:35:23 GMT jsensharma 2017-12-21T07:35:23Z