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Namenode port 8020 not accessible from outside.

Namenode port 8020 not accessible from outside.

New Contributor

I am trying to access my Namenode port 8020 from outside the cluster but its not accessible. My cluster is setup in Azure environment. I am getting the following error

 

[hdfs-hdfsSink-call-runner-0] (org.apache.hadoop.ipc.Client$Connection.handleConnectionFailure:666)  - Retrying connect to server: xxxxx-dn0.xxx.cloudapp.azure.com/1xx.2xx.2x.1xx:8020. Already tried 1 time(s)

I have already made changes in each /etc/hosts file like that

 

original setting

---------------------

10.0.0.10 xxxxxx-mn0.xxx.cloudapp.azure.com xxxxxx-mn0
10.0.0.20 xxxxxx-dn0.xxx.cloudapp.azure.com xxxxxx-dn0
10.0.0.21 xxxxxx-dn1.xxx.cloudapp.azure.com xxxxxx-dn1
10.0.0.22 xxxxxx-dn2.xxx.cloudapp.azure.com xxxxxx-dn2

 

Replace local ip address from public ip address

-------------------------------------------------------------------

1xx.1x.1x3.1x1 xxxxxx-mn0.xxx.cloudapp.azure.com xxxxxx-mn0
1xx.1x.1x3.1x2 xxxxxx-dn0.xxx.cloudapp.azure.com xxxxxx-dn0
1xx.1x.1x4.1x3 xxxxxx-dn1.xxx.cloudapp.azure.com xxxxxx-dn1
1xx.1x.1x5.1x4 xxxxxx-dn2.xxx.cloudapp.azure.com xxxxxx-dn2

 

xxxxxx-dn0 is my Namenode.

 

In the HDFS configuration in Cloudera Manager property Bind NameNode to Wildcard Address also check.

 

[root@xxxxxx-dn0 ~]# sudo netstat -tulpn | grep :8020
tcp 0 0 0.0.0.0:8020 0.0.0.0:* LISTEN 31540/java

 

Please help me.

 

 

 

8 REPLIES 8

Re: Namenode port 8020 not accessible from outside.

Cloudera Employee

Can you verify which server the name node is running on? By default it should be on mn0- .

Re: Namenode port 8020 not accessible from outside.

New Contributor
My Namenode is running on xxxxxx-dn0.

Re: Namenode port 8020 not accessible from outside.

New Contributor

Hi, can you please help - it is urgent. We are going to run POC based on Cloudera (5.7) in Azure and we have exactly same problem. Port 8020 is not accessible outside of cluster (we tested 2 various cluster in two various Azure subscription). Inbound security rules for MN nodes is allowed, Bind Namenode is allowed to. Thank you.

Highlighted

Re: Namenode port 8020 not accessible from outside.

Cloudera Employee

The namenode is running on xxxxxx-mn0.xxx.cloudapp.azure.com xxxxxx-mn0 unless someone changed something. It appears you are trying to connect to the wrong node if you use the default rules.

 

If you also connected to an existing vNet that vNet's rules are in place. You would need to work with the creator of that vNet to make sure the appropriate rules are in place to connect.

Re: Namenode port 8020 not accessible from outside.

New Contributor

Hello, I have tried this against node with mn0 prefix and had same result. I have allowed comunication on NSG on VNET and NSG for Public IP. Is there anything else I can check?

Thanks

Re: Namenode port 8020 not accessible from outside.

New Contributor

Got it! Namenode has to be binded to wildcard and you also have to do this:

  • Stop IP tables
  • Edit etc/hosts and add records for both internal and external namenode IP (I coudnt find this in any documentation or forum)
  • Start IP tables
  • Reboot namenode

Helped me after very long trobleshooting

Re: Namenode port 8020 not accessible from outside.

Explorer

Hope you have done it already.

1. try to ping the clouder IP

2. add entry in your hosts file where you are trying 

Re: Namenode port 8020 not accessible from outside.

New Contributor

Hello, I have same configuration, tried same steps and still have the same problem. Can somebody help please?