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Connection to NameNode refused

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Connection to NameNode refused

Explorer

Hi to all,

Ambari shows alerts on Zookeper service and Ambari Infra service with this message on the picture in attachement.

Host is also a zookeeper server and Namenode.

I tried with synchronizing server clocks, but nothing.

HDP version: 2.6.0.3

Ambari version: 2.5.0.3

An ideas?

Thank you!


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5 REPLIES 5
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Re: Connection to NameNode refused

Mentor

@Tomislav Novosel

There are many reasons why you are encountering such issue ,lets start by checkin whether your namenode is consistent

sudo su - hdfs 
$ hdfs dfsadmin -safemode get 

If the namenode is in safe mode run the below create point in time edits

$ hdfs dfsadmin -saveNamespace 

Then run

$ hdfs dfsadmin -safemode leave 

Now you should connect if the above doesn't help revert

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Re: Connection to NameNode refused

Explorer

@Geoffrey Shelton Okot

Could you explain in little more details what I get with that commands?

I'm not catching you up.

Thanks.

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Re: Connection to NameNode refused

Mentor

@Tomislav Novosel

When HDFS has 2 components Slave process is data node while the master process is Namenode should not be in inconsistent state aka Safemode to be accessible for read and write.
So the above steps are to eliminate that doubt and proceed to the next step of diagnosis if your HDFS is in a consistent state.
HTH

Re: Connection to NameNode refused

Explorer

Ok, thank you.

I checked that on namenode and it says 'Safemode is OFF'

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Re: Connection to NameNode refused

Mentor

@Tomislav Novosel

Can you share the zookeeper log in /var/log ?

  • Make sure hostname is correct not Mixed cases [Upper&lower case], iptables stopped, SELinux are disables

Check

$ ps -aef 
  • for each process and kill it from cli [if you are able to see the process running]
  • Restart the process from ambari.

HTH

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