Hi @Shobhna Dhami ,
thanks for attaching the trace.
From Trace, it seems like you have a mytest.example.com that already exists in database.
I would suggest you raise a case with hortonworks support if you are a customer so that our engineers can fix this issue for you.
Or else.
Follow this steps .
1) take a DB backup ( so that you can restore incase you got something wrong in database)
pg_dump -U ambari ambari > ./ambari_$(date +"%Y%m%d%H%M%S").sql
2) stop Ambari-server
3) login to Postgres ( default password will be bigdata)
[root@aanaik1 ~]# psql -U ambari ambari
Password for user ambari:
psql (9.2.23)
Type "help" for help.
ambari=> select host_id,host_name,ipv4,public_host_name from ambari.hosts;
ambari=> SELECT * FROM ambari.hoststate;
<br>
you might find some duplicate entries for the host_name mytest.example.com.
you need to remove existing hosts after verifying that they do not have any services installed and not in use.
you can run the command :
ambari=> select * from hoststate where host_id in (select host_id from hosts where host_name like '%mytest.example.com%');
ambari=> delete from hoststate where host_id in (select host_id from hosts where host_name like '%mytest.example.com%');
ambari=> select * from hosts where host_name like '%mytest.example.com%' ;
ambari=> delete from hosts where host_name like '%mytest.example.com%' ;
and then try to run the host update command again.
This commands are as per my understanding on the issue. you might need to investigate based on contents of ambari.hosts and ambari.hoststate table as you are more aware then me about your cluster configuration.
I would suggest if it's your production cluster then you can actually contact hortonworks support for this operation here: https://hortonworks.com/services/support/
hope this helps.
If this helps.
Please accept the answer so that it will be helpfull for other users facing same issue. .
