I have installed HDP 2.5. Issue I am facing is since last few days nodemanagers are not able to communicate with resourcemanager.
I have verifie with below command that resourcemanager is listening on the same port. But when I try to telnet it it is giving an connection refuse error. In logs as well there is connection refuse error.
Found the answer, Issue was that resource manager process was starting on localhost loopback ip (127.0.0.1) due to which i was not able to get the response on telnet for internal ip. Solution i did is, simply I have commented localhost loopback ip (127.0.0.1) in /etc/hosts file and restarted the resource manager. After which resource manager got aligned with internal IP and I am able to telnet it now also it is accessible and responding to nodemanagers.