ambari/ambari-server/docs/api/v1/host-resources.md

Host Resources

###API Summary

• List hosts
• View host information
• Create host

###Properties

Property	Description
Hosts/host_name	The host name
Hosts/cluster_name	The name of the parent cluster
Hosts/ip	The host ip address
Hosts/total_mem	The total memory available on the host
Hosts/cpu_count	The cpu count of the host
Hosts/os_arch	The OS architechture of the host (e.g. x86_64)
Hosts/os_type	The OS type of the host (e.g. centos6)
Hosts/rack_info	The rack info of the host
Hosts/last_heartbeat_time	The time of the last heartbeat from the host in milliseconds since Unix epoch
Hosts/last_agent_env	Environment information from the host
Hosts/last_registration_time	The time of the last registration of the host in milliseconds since Unix epoc
Hosts/disk_info	The host disk information
Hosts/host_status	The host status (UNKNOWN, HEALTHY, UNHEALTHY)
Hosts/public_host_name	The public host name. Note that this property is typically populated during the creation of the host resource in a way that is particular to the environment. If the public hostname can not be determined then it will be the same as the host_name property.
Hosts/host_state	The host state
Hosts/desired_configs	The desired configurations

###States

The current state of a host resource can be determined by looking at the Hosts/host_state property.

GET api/v1/clusters/c1/hosts/h1?fields=Hosts/host_state

200 OK
{
  "href" : "your.ambari.server/api/v1/clusters/c1/hosts/h1?fields=Hosts/host_state",
  "Hosts" : {
    "cluster_name" : "c1",
    "host_state" : "HEALTHY",
    "host_name" : "h1"
  } 
}

The following table lists the possible values of the host resource Hosts/host_state.

<th>State</th>
<th>Description</th>

<td>INIT</td>
<td>New host state.</td>  

<td>WAITING_FOR_HOST_STATUS_UPDATES</td>
<td>Registration request is received from the Host but the host has not responded to its status update check.</td>  

<td>HEALTHY</td>
<td>The server is receiving heartbeats regularly from the host and the state of the host is healthy.</td>  

<td>HEARTBEAT_LOST</td>
<td>The server has not received a heartbeat from the host in the configured heartbeat expiry window.</td>  

<td>UNHEALTHY</td>
<td>Host is in unhealthy state as reported either by the Host itself or via any other additional means ( monitoring layer ).</td>