cloudera-scm-agent not starting

[#1]

Hello all,

I'm running into a strange problem while trying to add another system to my small cluster.  Specifically, I get a "Installation failed. Failed to receive heartbeat from agent" error from the manager, after the installation has finished.  The system I'm trying to install to is running CentOS 7.2.

As far as I can tell, everything gets installed correctly.  In cloudera-scm-agent.out I see only the following:

[16/Jun/2016 17:17:45 +0000] 2323 MainThread agent INFO SCM Agent Version: 5.7.0
[16/Jun/2016 17:22:25 +0000] 2470 MainThread agent INFO SCM Agent Version: 5.7.0
[16/Jun/2016 17:25:03 +0000] 391 MainThread agent INFO SCM Agent Version: 5.7.0

And there are no other logs to look at.

Is there any way to turn on additional debug logging for starting cloudera-scm-agent?  The agent just isn't starting properly, and so far I've found nothing to indicate why. 

Thanks.

--Brennon

[#2 · Accepted solution]

I found the problem by digging down the the actual daemon that got started and running it without the --daemon option.  The issue was that I had underscores in my hostnames.  Once I removed them the problem went away.

As a note, if cloudera-scm-agent doesn't work with underscores in the hostnames, this is something that should be caught earlier in the manager, for example when entering the hostnames for installation.