I tried to backup Ambari database following the steps from below URL:
https://ambari.apache.org/1.2.4/installing-hadoop-using-ambari/content/ambari-chap11.html Helvetica, sans-serif; font-size: 15px; line-height: After restarting the Ambari server, the AmbariWeb UI is stuck after login and the below error message is displayed on UI:
500 status code received on GET method for API: /api/v1/clusters/MyCluster/hosts?fields=Hosts/host_name,Hosts/maintenance_state,Hosts/public_host_name,Hosts/cpu_count,Hosts/ph_cpu_count,Hosts/host_status,Hosts/last_heartbeat_time,Hosts/ip,host_components/HostRoles/state,host_components/HostRoles/maintenance_state,host_components/HostRoles/stale_configs,host_components/HostRoles/service_name,metrics/disk,metrics/load/load_one,Hosts/total_mem,alerts/summary&minimal_response=true
On checking the ambari-server.out file, I could find below error:
com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException SEVERE: The RuntimeException could not be mapped to a response, re-throwing to the HTTP container java.lang.NullPointerException
Please advise.