几个月来,我一直在使用 StreamInsight for CEP,并且有兴趣转向 ASA。我有一个无法从 ASA 文档中回答的问题。在 StreamInsight 中,我可以更改事件的持续时间以从离散的时间点事件创建信号流。例如
var mySignal = from s in myEventStream
.AlterEventDuration(s => TimeSpan.MaxValue)
.ClipEventDuration(myEventStream, (s, e) => s.DeviceId == e.DeviceId && s.EventCode == e.EventCode && s.Value != e.Value)
.ShiftEventTime(e => TimeSpan.FromTicks(1))
where s.EventCode == "512"
join e in myEventStream on s.DeviceId equals e.DeviceId
select new
{
DeviceId = s.DeviceId,
EventCode = s.EventCode,
Start = s.Timestamp,
End = e.Timestamp,
Duration = e.Timestamp - s.Timestamp,
Value = s.Value
};
我想要做的是检测这个高/低类型信号和另一个时间点事件流之间的重叠。我怎样才能在 ASA 中达到同样的效果?
背景:我有将来自多个源的事件发送到天蓝色事件中心的设备。其中一些事件是来自联系人的开/关事件。每个触点类型由“EventCode”表示,“Value”字段指示触点是打开还是关闭。我正在寻找的是一个 ASA 查询,它将告诉我 EventCode 512 何时处于“开启”状态,同时 EventCode X 也处于“开启”状态。
解决方案
下面是来自@Andrew 的修改后的代码,它在开关打开时检测到联系人正在关闭。'inStream' 是在以 Timestamp 字段加时间戳的 WITH 语句中定义的:
SELECT
SwitchOpen.DeviceId,
SwitchOpen.Timestamp,
'511' AS [EventCode],
'Switch is Open' AS [EventDescription],
SwitchOpen.Value,
SwitchOpen.LocationCode
INTO [outStream]
FROM
[inStream] AS SwitchOpen
INNER JOIN [inStream] AS ContactClosed
ON SwitchOpen.DeviceId = ContactClosed.DeviceId
AND DateDiff(second, SwitchOpen, ContactClosed) BETWEEN 1 AND 3600
LEFT JOIN [inStream] AS SwitchClosed
ON SwitchOpen.DeviceId = SwitchClosed.DeviceId
AND SwitchClosed.EventCode = SwitchOpen.EventCode
AND SwitchClosed.Value != SwitchOpen.Value
AND DateDiff(second, SwitchOpen, SwitchClosed) BETWEEN 1 AND 3600
AND DateDiff(second, SwitchClosed, ContactClosed) BETWEEN 1 AND 3600
WHERE
SwitchOpen.Value = 0.0
AND SwitchOpen.EventCode = '256'
AND ContactClosed.Value = 1.0
AND ContactClosed.EventCode = '512'
AND SwitchClosed.Timestamp IS NULL