question Re: In name node and standby name node setup, can we add another standby node and make the 3rd one as ACTIVE? I want to remove present active node which is having low end configuration. in Archives of Support Questions (Read Only)

In name node and standby name node setup, can we add another standby node and make the 3rd one as ACTIVE? I want to remove present active node which is having low end configuration.

sabavivek — Thu, 15 Mar 2018 05:28:10 GMT

Re: In name node and standby name node setup, can we add another standby node and make the 3rd one as ACTIVE? I want to remove present active node which is having low end configuration.

Shelton — Thu, 15 Mar 2018 05:59:14 GMT

@Vivek Sabha
Unfortunately, that is not possible with the current versions of HDP aka Hadoop 2.0 but Hadoop 3.0 current GA will support more than 2 NameNodes.

See this doc which includes all the significant enhancements.
The only viable option is to migrate a Namenode from one machine to another via Ambari, that should be the only solution for you and here is a HCC document by Kuldeep Kulkarni that you could use as a guide, unfortunately its 2 years old valid for Ambari - 2.2.2.X running HDP - 2.2.X-->/2.4.X

Hope that helps

Re: In name node and standby name node setup, can we add another standby node and make the 3rd one as ACTIVE? I want to remove present active node which is having low end configuration.

sabavivek — Thu, 15 Mar 2018 06:05:36 GMT

Thanks. In this case, I have added 3rd as standby namenode which removes previous standby namenode.Can I make the new name node as Active and another node to remove existing primary by the same method?

Re: In name node and standby name node setup, can we add another standby node and make the 3rd one as ACTIVE? I want to remove present active node which is having low end configuration.

Shelton — Thu, 15 Mar 2018 06:14:41 GMT

@Vivek Sabha
Once your setup is correctly you can switch the standby to primary. I hope you have successfully moved your old standby to the new host and validated that indeed its taken over the role of standby !

If you have set up automatic failover with ZooKeeper Failover Controllers then the ZKFC processes will automatically transition the Standby NN to Active status if the current active is unresponsive.The cluster failover is automatically done by Ambari.

If you want to make your standby namenode the active one, you can stop the current active namenode (ensuring the current standby namenode is alive) and the current standby namenode will take over as the active namenode.