How to remove role from host

[#1]

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.

thanks 

[#2]

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 . 

[#3]

Hello 

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

thanks...douglas

[#4]

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.

[#5]

Prequistes  

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 

http://www.cloudera.com/documentation/manager/5-1-x/Cloudera-Manager-Managing-Clusters/cm5mc_role_in...

if you need more information please let me know