branch-1.2/ambari-web/app/assets/data/hosts/background_operations/bg_operations.json

  {
    "requestId"  : 23 ,
    "tasks" : [
    {
      "taskId": 1,
      "stageId": 2,
      "hostname": "x.y.z.com",
      "role": "NAMENODE",
      "command": "START",
      "status": "PENDING"
    },
    {
      "taskId": 2,
      "stageId": 3,
      "hostname": "a.b.c.com",
      "role": "DATANODE",
      "command": "START",
      "status": "PENDING"
    }
    ]
}