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How to remove role from host


Hello -


I realized I set up a couple of hosts with the data node role, but they do not need to have that role.  I have three other hosts with data node role.


How can I remove the role?  I do not see any way to simply remove the role.






if I understand clearly you need to remove a datanode from one your nodes ? 

Are you performing in testing enviroment  or production clusters ? 

whats the replication factor in your cluster

Please let me know . 



I just need to remove the Data Node role from a node that doesn't need to be a data node.

This is in a testing environment.  

Replication factor = 3




Expert Contributor

I's very easy, go to the service that containe this role -from the CM interface-, then click to instances, check the role in the host you need to remove it, and click remove.



if you are doing Prod / Test (Provided if you have huge amount of data in that desired datanode that you are going to decommision. 


Increase the Datanode network bandwidh. 

Maximum number of replication threads on a DataNode and 

Hard limit on the number of replication threads on a DataNode



Click on the Host that has Datanode Role  - Perform Decommision and once the decommissioned is finished 

that you can monitor in the Namenode Web UI 50070 . 




Sometime I would rather leave it as decommisioned state and later if you want to include the instance back as for scalability you follow the above same procedure instead of decommision u will click recommision that it joins back to the cluster . 



 if you want to delete the instance after decommisioning please follow the manual


if you need more information please let me know