Check the Ambari Server status. On the command line, type:
$ sudo ambari-server status
You should see a response that looks similar to the following:
Ambari Server running Found Ambari Server PID: 29003 at: /var/run/ambari-server/ambari-server.pid
If the server is not running, start it:
$ sudo ambari-server start
You should see the following response:
Ambari Server 'start' completed successfully.