@Adil BAKKOURI For changing file/dir permission you can use standard Unix/Linux commands something like following: # chown -R hdfs:hadoop /hadoop/hdfs/namenode/current/ (OR) # chown -R hdfs:hadoop /hadoop/hdfs/namenode . ... View more

@Adil BAKKOURI Thank you for sharing the NameNode logs. Base don the logs we can see that your NameNode is not starting successfully because of the following error: 2019-06-07 10:29:46,758 WARN  namenode.FSNamesystem (FSNamesystem.java:loadFromDisk(716)) - Encountered exception loading fsimage java.io.FileNotFoundException: /hadoop/hdfs/namenode/current/VERSION (Permission denied)     at java.io.RandomAccessFile.open0(Native Method)     at java.io.RandomAccessFile.open(RandomAccessFile.java:316)     at java.io.RandomAccessFile.<init>(RandomAccessFile.java:243) . Hence please check what is the permission set for various files and directories of your Hadoop installation. Ideally they should be owned by "hdfs:hadoop" something like following: [root@newhwx1 ~]# ls -lart /hadoop/hdfs/namenode/current/VERSION -rw-r--r--. 1 hdfs hadoop 206 Jun  6 06:13 /hadoop/hdfs/namenode/current/VERSION . So i am suspecting thet you might have mistakenly started your NameNode with some other user (like root user or some other user) and hence your installation files permissions might got changed. Please fix those file permissions and then try to restart the NameNode again. Please check the permissions of all the directory contents: Are these directories permission are same as the user who is running the HDFS NameNode? (ideally in HDP installation they are owned by "hdfs:hadoop" # ls -lart /hadoop/hdfs/namenode/current/ # ls -ld /hadoop/hdfs/namenode/current/ # ls -ld /hadoop/hdfs/namenode # ls -ld /hadoop/hdfs # ls -ld /hadoop . ... View more

@Monalisa Tripathy Did that answer your query? If yes, then please mark this thread as answered by clicking on the "Accept" button .. If you have any additional query then please post back. ... View more

@Rohit Sharma Did you find that the below query returned any record in your Ambari DB ? If, yes then that explains about the issue and the above shared article should help in getting it fixed. select * from alert_current where history_id not in (select alert_id from alert_history); . ... View more

@John Are you still getting the same error? Did it resolve the issue? ... View more

@Nani Bigdata Did that answer your query? It will be a good community practice to mark the answer as "Accept" if it answers your query or Post back if you have any additional query. ... View more

@Matas Mockus Alert notification is not related with the Service Auto Start feature. Those features will work separately. So if you have configured any notification like Email Alert Notification then once the component goes down the alert will still be triggered normally based ont he alert trigger interval set for those individual alerts telling that the component went down (Service Auto Start feature will work independently). ... View more

@Matas Mockus Auto Start of components should work if the following conditions are met: 1. The components were not gracefully stopped (via Ammari API calls or via UI). Means the components were abruptly killed/terminated due to Host reboot or due to some errors in those componentes. 2. As soon as the Host comes up at least Ambari Agent should be running as a service so that as soon as the host reboots the Ambari Agent comes up automatically. This is needed because the Ambari Agent sends the current state info of the components present in that host to Ambari Server and then Ambari checks the "desired state" of the components with the "actual State" of those components sent by the ambari agent. If the desired state of those component does not match (support in ambari DB the desired state is "STARTED" but agent says that those components are actually Down) then Ambari Server will send a recovery instruction to agents due to the AutoStart Setting. ... View more

@Rohit Sharma Your recent error indicates that there is some inconsistency in your Ambari DB. Due to this inconsistency the Ambari UI for Alerts page is not showing any alert details. Error Processing URI: /api/v1/clusters/cluster-name/alerts - (java.lang.NullPointerException) null . You can follow the below article to get this issue fixed. Please make sure to take a fresh Amabri DB dump for backup purpose before following the below article. https://community.hortonworks.com/content/supportkb/174817/ambari-alert-page-is-invisible-on-ambari-screen.html After performing the steps mentioned in the above article please do not forget to restart Ambari Server. ... View more