@irshan When you add balancer as a role in the HDFS cluster, it indeed will show as not started. So its an expected one. Coming to your main query, it could be possible that when you run the balancer, the balancer threshold could be with in the default percentage of 10, so it won't move the blocks. You may have to reduce the balance threshold and try again. ... View more

@mike_bronson7 these messages indicates that the Controller is being elected on other node and the current broker who is acting as a controller initiating a clean shutdown to handover the controller responsibilities to the newly elected controller. These messages are normal, but if you are facing frequent controller failures / elections / controller switches to other nodes then this could be a concern. As long as if this is happening for a genuine reason such as Cluster restart / controller broker restarts. This is valid. Also, if the Controller broker disconnects from Zookeeper and looses the Controller Znode then the other brokers participate on controller election, that would also trigger these messages ... View more

Why is it namenode become safe mode? ... View more

Hi, @mike_bronson7 did you try to delete the host from Ambari UI? if not please try that out first. You might need to stop the ambari server first delete entries from the backed DB commit the changes then start your ambari server. But I would recommend deleting if from Ambari UI and checking. ... View more

I was looking for the same info and found that great link below. https://hadoop.apache.org/docs/current/hadoop-distcp/DistCp.html I hope it can help you. Best, ... View more

Hi @mike_bronson7  Please check that if the RM is working fine or is it down. Please also check your zookeeper. Please check with telnet if you can connect to RMhost from other host. ... View more

thank you for response but look on that also 2024-03-18 19:31:52,673 WARN datanode.DataNode (BlockReceiver.java:receivePacket(701)) - Slow BlockReceiver write data to disk cost:756ms (threshold=300ms), volume=/data/sde/hadoop/hdfs/data 2024-03-18 19:35:15,334 WARN datanode.DataNode (BlockReceiver.java:receivePacket(701)) - Slow BlockReceiver write data to disk cost:377ms (threshold=300ms), volume=/data/sdc/hadoop/hdfs/data 2024-03-18 19:51:57,774 WARN datanode.DataNode (BlockReceiver.java:receivePacket(701)) - Slow BlockReceiver write data to disk cost:375ms (threshold=300ms), volume=/data/sdb/hadoop/hdfs/data As you can see the warning is also on local disks not only across the network In any case we already checked the network include the switches and we not found a problem Do you think its could be tuning issue in hdfs parameters or some parameters that can help   ... View more

fix: `componentname` should be `component_name` ... View more