@Adil BAKKOURI As we see this error: Call From node4.rh.bigdata.cluster/172.16.138.113 to node4.rh.bigdata.cluster:8020 failed on connection exception: java.net.ConnectException: Connection refused; So please verify these things first: (Also better to share those outputs here) 1. Login to your NameNode Host "node4.rh.bigdata.cluster" and verify if the port 8020 is listening when you are trying to access that port from other host? # netstat -tnlpa | grep 8020 # hostname -f # cat /etc/hosts # ifconfig *NOTE:* in the above netstat command output you do not see port 8020 is listening then you must have to check and share the NameNode logs "/var/log/hadoop/hdfs/hadoop-hdfs-namenode-*.log" to verify if it is showing any error ? Try to run the following command from Both the NameNodes one by one to see if both are returning correct results? # /usr/hdp/current/hadoop-hdfs-namenode/bin/hdfs dfsadmin -fs hdfs://node4.rh.bigdata.cluster:8020 -safemode get #### AND from other NameNode also # /usr/hdp/current/hadoop-hdfs-namenode/bin/hdfs dfsadmin -fs hdfs://$OTHER_NN_HOSTNAME:8020 -safemode get 3. Now login to the other host "node4.rh.bigdata.cluster" (172.16.138.113) Which seems to have the same Hostname. (OR if you see any other hostname in your log then login to that host) Which is trying to connect to NameNode and then verify if you are able to connect to NN host on port 8020? Verify of the NN host name is resolvable ? # telnet  node4.rh.bigdata.cluster  8020 (OR) # nc  -v  node4.rh.bigdata.cluster  8020 # cat /etc/hosts # nslookup  node4.rh.bigdata.cluster # nslookup 172.16.138.113 . ... View more

@Aishwarya Dixit Can you please try this If you are trying to access the Ranger UI link Via Ambari Quicklinks and if it is getting redirected to Https Ranger url. 1. Stop Ambari Server. # ambari-server stop 2. Edit the "/etc/ambari-server/conf/ambari.properties" file and update the values of these two properties as 0 http.strict-transport-security=max-age=0 views.http.strict-transport-security=max-age=0 3. Restart Ambari Server. # ambari-server start . 4. Open Fresh Incognito Mode Browser (to avoid any browser caching issue) Then try to access the links for ranger. ... View more

@Rahul Borkar May be you can try with the following kind of template: (Please see the attached file.) EDITED_hadoop-env_Template.txt ... View more

@Rahul Borkar Ambari Uses Jinja templates to create the files using the templates. Jinja has specific rules for variable substitution and is very strict about the missing quotes. Your template has few issues like it has incorrectly entered new line characters at many places when {{VARIABLE}} is occurring in your template ... then it is converted to { {VARIABLE}} Example: (in your case)       export JAVA_HOME={   {java_home}} Ideally it should be       export JAVA_HOME={{java_home}} Similarly your hadoop-env template has many new lines added in between {{ brackets. The other main issue is that your last line as missing quotation mark #This is Rahul export HADOOP_NAMENODE_OPTS="${HADOOP_NAMENODE_OPTS} -javaagent:/home/sshhdfsuser/jmx_prometheus_javaagent-0.11.0.jar=19850:/home/sshhdfsuser/namenode.yml Ideally it should be #This is Rahul export HADOOP_NAMENODE_OPTS="${HADOOP_NAMENODE_OPTS} -javaagent:/home/sshhdfsuser/jmx_prometheus_javaagent-0.11.0.jar=19850:/home/sshhdfsuser/namenode.yml" . . ... View more

@Rahul Borkar In an ambari managed cluster any changes made manually inside the scripts like "hadoop-env.sh" will be reverted back as soon as we restart those components from Ambari UI Because ambari will push the configs which are stored inside the ambari Db for those script templates to that host. Hence for making such changes you must use the Ambari UI / APIs , Like "Advanced hadoop-env" from ambari. After you made those changes from Ambari UI do you actually see the mentioned Java arguments when you try to run the following commands? # ps -ef | grep -i NameNode # ps -ef | grep -i DataNode A. If you do not see those "javaagent" options in the above commands output then it means that those changes were not applied properly. In that case please share the full "Advanced hadoop-env" template from ambari UI so that we can check if it was applied properly or not? B. If you are able to see the those "javaagent" options in the above process list command output then there may be something wrong in the either the file permissions "/home/hduser/jmx_prometheus_javaagent-0.11.0.jar" and "/home/hduser_/datanode.yml" Or the YAML file content might not be appropriate. As DataNode and NameNode processes run as "hdfs" user normally so please chekc the file permission and ownership. Can you please share the /home/hduser_/datanode.yml file content as well ? ... View more