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rerigster failed in Comfirm Hosts


I have met the pre-requisites including DNS, disabling selinux, disabling firewalld and so on.

Here's the mistake.


Here's part of the log in UI


Here's part of the ambari-agent.log


I really have no idea what goes wrong and what causes this problem.

I hope someone who met the similar problem could give me a hand and I will appriciate it.


Super Mentor

@Amaing Li

Ambari agents usually tries to connect to the following ports of ambari server.

   8440 (Handshake Port for Ambari Agents to Ambari Server)
   8441 (Registration and Heartbeat Port for Ambari Agents to Ambari Server)

From your agent log it looks like the https://h2.hdp:8440/connection_info port communication is fine from the agent host to the server. But later it gets connection failed message when agent sends a registration to ambari on port 8441 (https://h2.hdp:8441/agent/v1/register/h2/hdp)

- So can you please check if there is any issue on port 8441 communication?

- Additionally from ambari agent machine can you please try running the following command to see if you are able to connect without any issue?

# openssl   s_client   -connect   h2.hdp:8441


We Also see a WARNING message in your log as following so please check the output of "ifconfig -s" command is returning results properly or not? There is an issue reported regarding that warning : (should be addressed in Ambari 2.5) which might not be directly related to yur issue however would be best to check. - Can't get a network interfaces list from





Here's the result, is this right?


I minimally installed the centos and I checked that there's no ifconfig command available.

Thank you very much!


Thanks for you solution and I have solved the warning problem.

Super Mentor

@Amaing Li

When you see the error on on agent log ... do you notice any error / warning on the "/var/log/ambari-server/ambari-server.log" if yes then can you please share the complete stackTrace of the error ?


I have looked through the ambari-agent.log file and just like you said

the problem may lay in

8441(RegistrationandHeartbeatPortforAmbariAgents to AmbariServer)

Do you know any reason that can cause this connection failure?

I have posted the result of the following command

openssl   s_client   -connect   h2.hdp:8441

But I don't understand it.


@ Jay SenSharma I appreciate your advice. That's true, there is always a clue in the log but I often fogot to watch. By now I have not looked all the log file. I will look through the log entirely first to find the point that goes wrong.

@ Amaing

Try with openssl upgradation.