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esper - Esper EPL 模式只触发一次

问题描述

我正在尝试在 EPL 中创建一个模式，但我不明白为什么它只匹配一个。这是我在网页Esper EPL online上所做的。我在左侧文本框中输入的 EPL 是：

create schema StockTick(signature string, source string, destination string, action string);
@Name('Monitor') select * from StockTick;
@Name('Out') select * from pattern [A=StockTick -> B=StockTick(B.source = A.source and B.destination = A.destination and B.action='block') where timer:within(2 seconds)];

我在中间文本框中输入的事件是：

StockTick={signature='sig1', source ='s1', destination ='d1'}
t=t.plus(0.4 seconds)

StockTick={source ='s1', destination ='d1', action='block'}
t=t.plus(0.4 seconds)

StockTick={signature='sig2', source ='s2', destination ='d2'}
t=t.plus(0.4 seconds)

StockTick={source ='s2', destination ='d2', action='block'}
t=t.plus(0.4 seconds)

我在右框中得到的输出：

At: 2001-01-01 08:00:00.000
Statement: Monitor
Insert
StockTick={signature='sig1', source='s1', destination='d1', action=(null)}

At: 2001-01-01 08:00:00.400
Statement: Monitor
Insert
StockTick={signature=(null), source='s1', destination='d1', action='block'}
Statement: Out
Insert
stmt2_pat_0_1={A={StockTick={signature='sig1', source='s1', destination='d1', action=(null)}}, B={StockTick={signature=(null), source='s1', destination='d1', action='block'}}}

At: 2001-01-01 08:00:00.800
Statement: Monitor
Insert
StockTick={signature='sig2', source='s2', destination='d2', action=(null)}
At: 2001-01-01 08:00:01.200
Statement: Monitor
Insert
StockTick={signature=(null), source='s2', destination='d2', action='block'}

所以：

我不明白为什么 1.2 秒后我没有像我所期望的那样再次触发 Out 语句。

请注意，如果我单独尝试前两个插入，然后单独尝试后两个插入，在这两种情况下，我都会触发两次 Monitor 语句和触发一次 Out 语句。当我连接四个插入语句时，问题就出现了。

标签： esper

解决方案

感谢另一个论坛，我设法解决了这个问题。我错过了every定义模式的关键字，因此，在更新规则后如下：

@Name('Out') select * from pattern [every A=StockTick -> B=StockTick(B.source = A.source and B.destination = A.destination and B.action='block')];

它就像一个魅力：

At: 2001-01-01 08:00:00.000
Statement: Monitor
Insert
StockTick={signature='sig1', source='s1', destination='d1', action=(null)}

At: 2001-01-01 08:00:00.400
Statement: Monitor
Insert
StockTick={signature=(null), source='s1', destination='d1', action='block'}
Statement: Out
Insert
stmt2_pat_0_0={A={StockTick={signature='sig1', source='s1', destination='d1', action=(null)}}, B={StockTick={signature=(null), source='s1', destination='d1', action='block'}}}

At: 2001-01-01 08:00:00.800
Statement: Monitor
Insert
StockTick={signature='sig2', source='s2', destination='d2', action=(null)}

At: 2001-01-01 08:00:01.200
Statement: Monitor
Insert
StockTick={signature=(null), source='s2', destination='d2', action='block'}
Statement: Out
Insert
stmt2_pat_0_0={A={StockTick={signature='sig2', source='s2', destination='d2', action=(null)}}, B={StockTick={signature=(null), source='s2', destination='d2', action='block'}}}

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