Re: FlinkCEP - Detect absence of a certain event

[Humberto Rodriguez Avila]

Hello Fuji and Zhijiang


Thanks for time! 

Fuji thanks for the links 👍🏻

I hope that in the future similar scenarios can be implemented in FlinkCEP. 
Other CEPs like ESPER support this particular type of negated patterns.

Best regards,
Humberto

> On 19 Mar 2020, at 04:55, Shuai Xu <chigg...@gmail.com> wrote:
> 
> Hi Humberto,
> Unfortunately, the answer is NO. Now FlinkCEP doesn't support notFollowedBy 
> in the end of a Pattern, even with a time window. I have proposed an 
> improvement to enable it. The detail can be found in 
> https://lists.apache.org/thread.html/rc505728048663d672ad379578ac67d3219f6076986c80a2362802ebb%40%3Cdev.flink.apache.org%3E
>  
> <https://lists.apache.org/thread.html/rc505728048663d672ad379578ac67d3219f6076986c80a2362802ebb%40%3Cdev.flink.apache.org%3E>.
>  However, I didn't receive enough responses, so this work is suspended now.
> 
> Zhijiang <wangzhijiang...@aliyun.com <mailto:wangzhijiang...@aliyun.com>> 
> 于2020年3月19日周四 上午11:41写道：
> Hi Humberto,
> 
> I guess Fuji is familiar with Flink CEP and he can answer your proposed 
> question. I already cc him.
> 
> Best,
> Zhijiang
> 
> ------------------------------------------------------------------
> From:Humberto Rodriguez Avila <rhumber...@outlook.com 
> <mailto:rhumber...@outlook.com>>
> Send Time:2020 Mar. 18 (Wed.) 17:31
> To:user <user@flink.apache.org <mailto:user@flink.apache.org>>
> Subject:FlinkCEP - Detect absence of a certain event
> 
> In the documentation of FlinkCEP, I found that I can enforce that a 
> particular event doesn't occur between two other events using notFollowedBy 
> or notNext.
> 
> However, I was wondering If I could detect the absence of a certain event 
> after a time X. For example, if an event A is not followed by another event A 
> within 10 seconds, fire an alert or do something.
> 
> Could be possible to define a FlinkCEP pattern to capture that situation?
> 
> Thanks in advance, Humberto
> 
>