In my experience, lack of computer resources was the biggest cause. It is always necessary to prepare disks and memory with sufficient space. ... View more

When we restart the JournalNode Quorum the epoch number will change. We usually see that the errors when the JournalNodes are not in sync.  Check for the writer epoch on current dir for JournalNode process, which one of the JournalNodes is lacking we can manually copy the files from working JournalNode and it will pick up.  This should happen automatically when we restart the JournalNodes, if not then above is the procedure.   ... View more

@ni4ni  mentions, There is no standby/secondary NN. ... View more

I appreciate your answer, could you please tell me what is the meaning of No JVM present. And what is the default location of the Namenode log file?   Thank you,   ... View more

Hello @Masood, I believe you are asking the commands to run in order to determine the active NN apart from CM UI ( CM > HDFS > Instance > NameNode)   From CLI you have to run couple of commands to detemrine the Active/Standby NN   List the namenode hostnames # hdfs getconf -namenodes c2301-node2.coelab.cloudera.com c2301-node3.coelab.cloudera.com   Get nameservice name # hdfs getconf -confKey dfs.nameservices nameservice1   Get active and standby namenodes # hdfs getconf -confKey dfs.ha.namenodes.nameservice1 namenode11,namenode20   # su - hdfs $ hdfs haadmin -getServiceState namenode11 active $ hdfs haadmin -getServiceState namenode20 standby   Get active and standby namenode hostnames   $ hdfs getconf -confKey dfs.namenode.rpc-address.nameservice1.namenode11 c2301-node2.coelab.cloudera.com:8020   $ hdfs getconf -confKey dfs.namenode.rpc-address.nameservice1.namenode20 c2301-node3.coelab.cloudera.com:8020   If you want to get the active namenode hostname from hdfs-site.xml file, you can go through following python script in github – https://github.com/grakala/getActiveNN.   Thank you  ... View more

Check the usage of the cluster when you submit the Job in YARN. Share the log if you can ... View more