通过ecs的sdk获得机器监控数据不完整

通过云服务ecs的sdk获取MonitorData数据，结果如下：
{
"RequestId": "8B2222B0-860E-41C1-B620-E291CBE15F81",
"MonitorData": {
"InstanceMonitorData": [
{
"TimeStamp": "2016-01-21T12:00:00Z",
"BPSWrite": 0,
"InternetRX": 29,
"InstanceId": "i-94z9ptm2i"
},
{
"IOPSRead": 1,
"InstanceId": "i-94z9ptm2i",
"TimeStamp": "2016-01-21T12:01:00Z",
"IOPSWrite": 0,
"InternetTX": 0
},
{
"InstanceId": "i-94z9ptm2i",
"TimeStamp": "2016-01-21T12:03:00Z",
"InternetBandwidth": 6
}
]
}
}






可以看到返回的数据并不完整，正常完整的数据应该是如下所示的：
{
            "InstanceId": "Bc0102-23xYm09",
            "CPU": 0,
            "IntranetRX": 122,
            "IntranetTX": 343,
            "IntranetFlow": 675,
            "IntranetBandwidth": 10,
            "InternetRX": 122,
            "InternetTX": 343,
            "InternetFlow": 675,
            "InternetBandwidth": 10,
            "IOPSRead": 1000,
            "IOPSWrite": 200,
            "BPSRead": 1000,
            "BPSWrite": 200,
            "TimeStamp": "2010-01-21T09:50:23Z"
        }




为什么实际返回的数据与示例中的数据相对比会有这样的反差呢？