列出警报阈值

列出所有配置的警报阈值。

请求示例：

GET /api/alert/v1/thresholds HTTP/1.1
Authorization: Basic abcd123MWE=
Host: zfssa.example.com:215
Accept: application/json

响应示例：

HTTP/1.1 200 OK
Date: Tue, 27 Aug 2013 17:38:40 GMT
X-Zfssa-Appliance-Api: 1.0
Content-Type: application/json
Content-Length: 689

{
    "thresholds": [
        {
            "days": "all",
            "frequency": 300,
            "href": "/api/alert/v1/thresholds/
                     bec758cb-346e-6a7d-c211-b320c09ef6a6",
            "limit": 500,
            "minclear": 300,
            "minpost": 300,
            "statname": "cpu.utilization",
            "threshold": "threshold-000",
            "type": "normal",
            "uuid": "bec758cb-346e-6a7d-c211-b320c09ef6a6",
            "window_end": 0,
            "window_start": -1
        },
        {
            "days": "all",
            "frequency": 300,
            "href": "/api/alert/v1/thresholds/
                     475799d8-32c8-6ff6-882c-aa3b66e3a5a2",
            "limit": 100000,
            "minclear": 600,
            "minpost": 300,
            "statname": "datalink.kilobytes",
            "threshold": "threshold-001",
            "type": "normal",
            "uuid": "475799d8-32c8-6ff6-882c-aa3b66e3a5a2",
            "window_end": 300,
            "window_start": 1200
        }
    ]
}