计算时间戳

获取 2018/04/12 00:00:00 ~ 2018/04/12 10:00:00 的内存使用记录

转换为时间戳: 1523462400 ~ 1523498400

获取总内存vm.memory.size[total]与可用内存vm.memory.size[available]的itemid

Payload:

{
    "jsonrpc": "2.0",
    "method": "item.get",
    "params": {
        "output": ["itemid","hostid","key_","value_type","status","units"],
        "hostids": "10254",
        "search": {
            "key_": "vm.memory.size[total]"
        },
        "sortfield": "name"
    },
    "auth": "54ec7f0d103f635ada0a76147d8a93a5",
    "id": 1
}

Response:

{
  "jsonrpc": "2.0",
  "result": [
    {
      "itemid": "28272",
      "hostid": "10254",
      "key_": "vm.memory.size[total]",
      "value_type": "3",
      "status": "0",
      "units": "B"
    }
  ],
  "id": 1
}

Payload:

{
    "jsonrpc": "2.0",
    "method": "item.get",
    "params": {
        "output": ["itemid","hostid","key_","value_type","status","units"],
        "hostids": "10254",
        "search": {
            "key_": "vm.memory.size[available]"
        },
        "sortfield": "name"
    },
    "auth": "54ec7f0d103f635ada0a76147d8a93a5",
    "id": 1
}

Response:

{
  "jsonrpc": "2.0",
  "result": [
    {
      "itemid": "28317",
      "hostid": "10254",
      "key_": "vm.memory.size[available]",
      "value_type": "3",
      "status": "0",
      "units": "B"
    }
  ],
  "id": 1
}

记录下两个item id 分别为28272, 28317

分别获取total memory 与 available memory 的history值

Payload:

{
    "jsonrpc": "2.0",
    "method": "history.get",
    "params": {
        "output": "extend",
        "history": 3,
        "itemids": "28272",
        "sortfield": "clock",
        "sortorder": "DESC",
        "time_from": "1523462400",
        "time_till": "1523498400"
    },
    "auth": "54ec7f0d103f635ada0a76147d8a93a5",
    "id": 1
}

Respones:

{
  "jsonrpc": "2.0",
  "result": [ 
    {
      "itemid": "28272",
      "clock": "1523497872",
      "value": "3958050816", 
      "ns": "360074776"
    },
    {
      "itemid": "28272",
      "clock": "1523494272",
      "value": "3958050816",
      "ns": "331780004"
    },
    {
      "itemid": "28272",
      "clock": "1523490672",
      "value": "3958050816",
      "ns": "771174968"
    },
    ...
    ...
    {
      "itemid": "28317",
      "clock": "1523462577",
      "value": "1576091648",
      "ns": "50470151"
    },
    {
      "itemid": "28317",
      "clock": "1523462517",
      "value": "1576214528",
      "ns": "469703166"
    },
    {
      "itemid": "28317",
      "clock": "1523462457",
      "value": "1576411136",
      "ns": "848907144"
    }
  ],
  "id": 1
}

内存使用率计算公式为: available memroy/total memory * 100 %, 这里total memroy一般为恒定值