Support Questions

Find answers, ask questions, and share your expertise
Celebrating as our community reaches 100,000 members! Thank you!

How to check if my Secondary Name Node is synced up with the cluster?


Hi all,

This question is in continuation to:

Scenario: I have a 12 node cluster (machines 01-12) with 8 data nodes. 06, 07 are the NN and SNN respectively. 01 and 12 run the Hive related services. This cluster was upgraded to 12 node from 4 node where 01 was the namenode and 02-05 were the data nodes.

So I used the "Move Namenode" and "Move Snamenode" wizards on Ambari to move the nn and snn from 01 to 06 and 07 respectively. I verified all the services running on nn are running on snn as well. Now I want to check if my snn is working properly. So I shut down all the services on nn and tried to connect to Hive from one of the hosts (02) and it failed with the error:

Call From <machine_02/ip_address_of_02> to <machine_06:8020> failed on connection exception: Connection refused; For more details see:

I don't know why it is trying to connect to nn (06) and not snn (07). Can someone point what I am missing here?


Super Collaborator

Since you are talking about secondary NameNode, a Secondary NameNode will never act as a Name/meta data service provider even if you shutdown primary Namenode. You will have to switch Secondary Namenode to standby NameNode using HA.

You can read here -

One way to check if your secondary NN has all latest fs image is by checking the size of CURRENT directory of NN and SNN.

Master Mentor

@Sree Kupp

I see you are attempting something that is taken care of by real HA setup with active and standby namenode, you can use below command to force failover.

$ hdfs haadmin -failover

Let me know whether that helps