@mike_bronson7  Adding to @GangWar :-   To your question - dose this action could also affected the data itself on the data-nodes machines ?   No it doesnt affect data on datanode directly. This is metadata operation on namenode which when need to be run  when NameNode fails to progress through the edits or fsimage  then the NameNode may need to be started with -recover option.    Since the metadata has reference to the blocks on datanode, hence this is a critical operation and may incur data loss. ... View more

Adding to @smdas    This is one of the kudu limitations :- "There is no way to run compaction manually, but dropping the table will reclaim the space immediately."    You can verify the size from CM graphs:- Go to the Kudu service and navigate to the Charts Library tab. On the left-hand side menu, click Tables to display the list of tables currently stored in Kudu. Click on a table name to view the default dashboard for that table. The Total Tablet Size On Disk Across Kudu Replicas chart displays the total size of the table on disk using a time-series chart. Hovering with your mouse over the line on the chart opens a small pop-up window that displays information about that data point. Click the data stream within the chart to display a larger pop-up window that includes additional information for the table at the point in time where the mouse was clicked.   reference :- http://apache.github.io/kudu/docs/known_issues.html#_other_usage_limitations ... View more

Hi Prash,   By default CM will throw an alert on CM->HDFS ->status page when the namenode is in Safe Mode.    NameNode Safemode Health Test - Enables the health test that the NameNode is not in safemode https://docs.cloudera.com/documentation/enterprise/6/properties/6.1/topics/cm_props_cdh5150_hdfs.html You can configure email Alert, using the below  https://docs.cloudera.com/documentation/enterprise/latest/topics/cm_ag_email.html   Let me know if that helps.   Thanks Vipin ... View more

Hi @AM ,   The alert regarding fd is a warning message that you have crossed the warning threshold of open fds for kudu.    Ideally there are 3 sources which hold up the fds in kudu.  1. File cache 2. Hot replica  3. cold replica   Typically there is no downside of increasing the fds in kudu tserver. You can increase the fds from CM->kudu->config->file descriptor ->increase the value to 64k or you may also tune the threshold and set the warning to 75%.   Restart of TS is required if you tune the file descriptor.    Hope this helps!!     ... View more

Hi @dsht6955 , Can you try running the hdfs oiv command with -t flag as show below and see if that helps:   hdfs oiv -p Delimited -delimiter delimiterString -t temporaryDir -i fsimage -o output.xml   Thanks Vipin ... View more

It seems NN refuses to connect to DN, it could be DN is not there in include list file on NN or maybe DNS issue (check /etc/hosts). Can you run the below command and see if the error goes off- hdfs dfsadmin -refreshNodes   Further, Check this link - https://stackoverflow.com/questions/17252955/getting-the-following-error-datanode-denied-communication-with-namenode-while/29598059#29598059 ... View more

CDP isn't 100% open source. You may have to purchase the subscription.   Trial can be download from here- https://www.cloudera.com/downloads.html   "THE TRIAL VERSION INCLUDES ALL FEATURES OF THE FULL PRODUCT AND IS VALID FOR 60 DAYS FROM THE TIME OF INSTALLATION." ... View more

Hi Vijaya,   Under-replicated blocks are the blocks which does not meet the target replication factor. HDFS has self healing mechanism wherein it will create new replicas of under-replicated blocks until they meet the target replication.  if multi node cluster then you can verify if any datanodes are down  Or if it is one node cluster then please ensure replication factor is set to 1.    Thanks. ... View more

-> I dont think there's a way as of now to check the overall capacity of kudu. However, You can check the individual kudu tserver size on disk by using the linux command on the host "du -sh" /<kudu-path>/   Further you can check the individual table size on disk by using CM charts.   How much space a Kudu table is using on disk: 1. Go to the Kudu service and navigate to the Charts Library tab. 2. On the left-hand side menu, click Tables to display the list of tables currently stored in Kudu. 3. Click on a table name to view the default dashboard for that table. The Total Tablet Size On Disk Across Kudu Replicas chart displays the total size of the table on disk using a time-series chart. Hovering with your mouse over the line on the chart opens a small pop-up window that displays information about that data point. Click the data stream within the chart to display a larger pop-up window that includes additional information for the table at the point in time where the mouse was clicked.   Link- https://www.cloudera.com/documentation/enterprise/latest/topics/cm_mc_kudu_service.html#charts_library Hope this helps. ... View more