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Ambari host registration failed

Rising Star

I am trying to add a new host to my existing cluster. Below is what I have done so far:

a.) I installed Ambari-Agent on the new hosts and modified the INI file to point to the ambari-server hosts

b.) Verified that new host is able to ping ambari-server and vice versa.

c.) Verified that the Ambari-Server port is open from the new hosts

What else Ambari-Server looks for ? If it can ping the new host and new host can ping and the ambari-server is reachable why it can't register. What's the missing part ?

Thanks

Prakash

1 ACCEPTED SOLUTION

Ping is not enough. If you run iptables, stop them for a while to see if some ports are blocked. Agents are accessing the server at 8080, 8440 and 8441, and the server is pinging agents at 8670. Details are here. And, well, you haven't mentioned starting ambari-agent, but I'm sure you did it.

View solution in original post

16 REPLIES 16

Mentor

whata does the Ambari server log say?

Ping is not enough. If you run iptables, stop them for a while to see if some ports are blocked. Agents are accessing the server at 8080, 8440 and 8441, and the server is pinging agents at 8670. Details are here. And, well, you haven't mentioned starting ambari-agent, but I'm sure you did it.

Rising Star

Thanks. Not sure what was wrong but I restarted AMbari-Agent and this time it got connected..

Thanks

Mentor

@Prakash Punj

Sorry what you ave done on the new host is not enough . There are are more important steps that you should never ignore, Assuming that the your corporate or whatever network rules allows the new host and the Ambari server to communicate no proxy or firewall rules etc.

  • Assuming you are on linux both hosts should have FQDN entries in the /etc/host
  • Configure passwordless connection for the user installing hetween the 2 host etc

Just have a look at attached document and again IGNORE nothing all have to be successful implemented to succeed your new host integration to your cluster

PS.remember to clean the failed registration too

Rising Star

Thanks. Actually I did all those host entries but still it was failing. So today I rebooted the machine and restarted Ambari-Agent and it was able to connect..

Thanks

Contributor

hi, I had the same problem as Prakash. I read the pdf you've attached. most steps were done before. the only change I made was disabling transparent huge page.

after that my ambari failed to start. i tried stop/start and even remove/install ambari. but the error resists. I even enabled THP again. actually when I start the service, it says it was successful, but the answer to 'systemctl status ambari-server' is:

ambari-server.service - LSB: ambari-server daemon Loaded: loaded (/etc/rc.d/init.d/ambari-

server; bad; vendor preset: disabled) Active: failed (Result: exit-code) since Mon 2017-05-01 04:52:43 UTC; 40min ago Docs: man:systemd-sysv-generator(8)

May 01 04:52:43 node1.novalocal systemd[1]: Starting LSB: ambari-server daem.... May 01 04:52:43 node1.novalocal ambari-server[3400]: Need python version > 2.6 May 01 04:52:43 node1.novalocal systemd[1]: ambari-server.service: control p...1 May 01 04:52:43 node1.novalocal systemd[1]: Failed to start LSB: ambari-serv.... May 01 04:52:43 node1.novalocal systemd[1]: Unit ambari-server.service enter.... May 01 04:52:43 node1.novalocal systemd[1]: ambari-server.service failed. Hint: Some lines were ellipsized, use -l to show in full.

@Prakash Punj

I hope you have stopped iptables and disabled selinux as others have suggested. Please ensure that passwordless connection is going ok between the nodes. Is the right id_rsa copied to the host registration? Else, add the node manually. To do this, install ambari-agent manually in the host being added and then try the registration.

Mentor

@Prakash Punj

Definitely all the steps I attached MUST be implemented but if the Ambari server had already locked that port for use then subsequent attempts would't work untill the process using that Ambari port is killed .

Happy it worked out for you.

New Contributor

Update: 11/20/2016

For using Ambari-agent , must include this vital missing code when editing ambari server hostname in

/etc/ambari-agent/conf/ambari-agent.ini.

I couldn' get the host to talk to Ambari server until i put this (ip_addres=x.x.x.x) in.

vi /etc/ambari-agent/conf/amabari-agent.ini

[server]

hostname=your.ambari_server.name

ip_address=x.x.x.x <--------------this is most important to ensure the host can talk to ur ambari server

url_port=8440

secured_url_port=8441

New Contributor

I had a similar issue and wanted to add my findings to hopefully help those in the future reading this note. I went through all the above checks with ports, firewalls, TPH, etc and the new host still failed to register. Finally during some checking, I noticed the /etc/hosts file had a different name than what was in DNS for this host IP(the server was built with a different host name, then renamed without changing /etc/hosts). Since DNS resolved to the correct IP all the port checking worked. However, I assume when the ambari-agent was started it read the hosts file so it knew itself as the hostname in the /etc/hosts file which was incorrect. After updating the /etc/hosts file and restarting the ambari-agent everything worked.

New Contributor

To solve this issues you should be known these things first:-

  • try to use the private SSH key in the ambari service host .
  • copy the private key to the public key and use this copy key
  • try to keep the private key file into the web UI

New Contributor

So today I rebooted the machine and restarted Ambari-Agent and it was able to connect.. ince DNS resolved to the correct IP all the port checking worked. However, I assume when the ambari-agent

,

Since DNS resolved to the correct IP all the port checking worked. However, I assume when the ambari-agent was started it read the hosts file so it knew itself as the hostname

I want to Ambari to build a platform for testing some functionalities on spark. I use Win 10+Hyper-V to create two VMs (mercury.gc and venus.gc) installed with CentOS 7. Ambari 2.2.2.0 is installed on one VM (mercury.gc) and try to use it to config these two VMs.

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Expert Contributor

Ambari agent could also fail due to a bug which requires:


force_https_protocol=PROTOCOL_TLSv1_2
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