how to detected HeartBeat Lost state between ambari agent to ambari server

[#1]

we want to find the **approach / test /cli / API** that gives us the results about HeartBeat Lost between Ambari agent to Ambari server

HeartBeat Lost could be as results of poor connection between Ambari agent to Ambari server or because Ambari server was down for along time , etc

Note - from Ambari GUI the machine with **HeartBeat Lost** state usually colored by yellow state

clarification:

the case as described here appears when `ambari-agent status` is in running state as the following

ambari-agent status
Found ambari-agent PID: 119315
ambari-agent running.
Agent PID at: /run/ambari-agent/ambari-agent.pid
Agent out at: /var/log/ambari-agent/ambari-agent.out
Agent log at: /var/log/ambari-agent/ambari-agent.log

[#2]

The following areas normally cause this problem:

1) the connection from Ambari agent host to Ambari Server got lost.
2) firewall issue blocked connections.
3) hostname and IP address are not being set correctly in /etc/hosts

You can compare the output using these APIs:

> curl ­u user:passwd http://AmbariHost:8080/api/v1/hosts

[#3 · Accepted solution]

The following areas normally cause this problem:

1) the connection from Ambari agent host to Ambari Server got lost.
2) firewall issue blocked connections.
3) hostname and IP address are not being set correctly in /etc/hosts

You can compare the output using these APIs:

> curl ­u user:paswd http://AmbariHost:8080/api/v1/hosts