SSH key question

[#1]

Hello! I have a question:

Is it only needed to to copy SSH public key, generated in ambari server (Root), to all hosts which are going to be part of the cluster and make sure you can ssh from ambari server to hosts without PW ? OR do I also need to be able to SSH between hosts (Between slave1 --> slave2) or is it enough if ambari server is able to login to hosts and installation process makes sure that also slaves, if needed, are able to do login ?

I am asking this because I am having a problem with HDP 2.3 installation: All components install fine, but installation finish with orange bar .. and thats because Ambari is not able to start components after install (some of them yes, but not all, like timeline app server, yarn .. are not started). My guess is that its something to do with connections between nodes ,and I am not talking FW issues .. I have Ubuntu 14.04 with dos (which works .. I can ssh using hostnames)..

[#2 · Accepted solution]

Yes, you just need to connect passwordless from ambari host to all other hosts. You don't need to have root-equivalence between slaves. Could you paste the errors you get in starting components?

[#3]

Thanks for the reply. My problems might be dns related .. My ubuntu has DNS and it worked like charm, but after I updated my Asus router somehow it stopped working .. So, I am back to good old hosts - file and doing reinstall with this setup. I let you know if I face issues.

[#4]

And it was DNS related... So, now its working 🙂

[#5]

Ok, perfect! 🙂