@rahul gulati Check if the below think works and resolve the issue - Suspected the issue is with snmpd service not installed or installed and not running. Execute: 1) service snmpd start If this does not recognize the service then snmpd needs to be installed and proceed with remaining steps. 2) yum -y install net-snmp net-snmp-utils 3) service snmpd start ... View more

@rahul gulati Yes, its a bug also reported in HDP JIRA - https://hortonworks.jira.com/browse/BUG-70990 [Internal link for reference] This will be fixed in up coming Ambari Release version 2.5.0. If you are looking to get a patch to Fix this issue, please reach out to Hortonworks Support team to get Subscription. ... View more

@oussama ben lamine Can you pass me the output of command - $ps -aef |grep namenode $netstat -taupen |grep <pid_of_namenode> $cat /etc/hosts $ifconfig ... View more

@oussama ben lamine Suspected you are hitting - https://issues.apache.org/jira/browse/AMBARI-10021 Can you just restart the Machine and check to start the namenode process again. Let me know if that helps. Please do make sure you have iptables and selinux disabled and hostname set correctly. Check $hostname and $hostname -f output. Both should match. ... View more

@Morten R. Try to modify ambari-agent.ini and use "hostname=<ambari-server hostname/ipaddress>" instead of 127.0.0.1 Restart ambari agent and let me know if it works. Make sure Iptables and selinux must be disabled. Also make sure you must be able to ssh from ambari-server to both ambari-agent nodes passwordless. ... View more

@Alexander E Please login to ambari UI and check if the namenode service is started or not. Since from the logs below it seems your namenode is down - Failed to connect to node0 port 50070: connection refused Also it might happen sometimes, the namenode takes long time to start and before that if the Yarn is started it tried to connect namenode (which is still getting up) For such scenario's make sure namenode is up and then restart YARN service again. ... View more

@Edgar Daeds Can you check below things - 1. is your test connection for repository work successfully ? 2. Do you see any alert in Ambari UI wrt "Ranger Admin Password check"? 3. If that is HDFS policy can you check namenode logs if you any error there ? Please post more logs to analyze the issue. ... View more

@chennuri gouri shankar Please check if this is what you are looking for - http://hortonworks.com/blog/hdf-2-0-apache-nifi-integration-apache-ambariranger/ https://cwiki.apache.org/confluence/display/RANGER/NiFi+Plugin ... View more

@PJ If you are using ambari, then you need to modify Services->HDFS->Configs->"hadoop-env template" [depending on your java version you are using ie. >Java 8 or <Java 8] ... View more

@Ka Tang Can you make sure you have local repository for centos7 packages also in place? ... View more