ambari + Standby NameNode not started

[#1]

please advice what is the solution for this problem

we are getting this errors ( from the log under /var/lib/ambari-agent/data )

2017-11-13 11:49:49,056 - Getting jmx metrics from NN failed. URL: http://master01.sys56.com:50070/jmx?qry=Hadoop:service=NameNode,name=FSNamesystem
Traceback (most recent call last):ExecutionFailed: Execution of 'curl -s 'http://master01.sys56.com:50070/jmx?qry=Hadoop:service=NameNode,name=FSNamesystem'

we also tried this solution but without results: https://community.hortonworks.com/articles/114869/how-to-resolve-namenode-nn1-is-not-listed-as-activ...

and when we try it manual

curl -s 'http://master01.sys56:50070/jmx?qry=Hadoop:service=NameNode,name=FSNamesystem'

we get

 echo $?

7

[#2 · Accepted solution]

we solved this issue by do the following:

we notice that no SSH from the host with ( ambari-server ) to all machines in the cluster ,

so we copy the public key from the master machine ( ambari-server ) to each machine in the cluster , and restart the node that ( Standby NameNode ) was downe