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From Sameer Wadkar <sam...@axiomine.com>
Subject Re: Flink : CEP processing
Date Tue, 09 Aug 2016 18:28:52 GMT
In that case you need to get them into one stream somehow (keyBy a dummy value for example).
There is always some logical key to keyBy on when data is arriving from multiple sources (ex
some portion of the time stamp). 

You are looking for patterns within something (events happening around the same time but arriving
from multiple devices). That something should be the key. That's how I am using it. 

Sameer

Sent from my iPhone

> On Aug 9, 2016, at 1:40 PM, M Singh <mans2singh@yahoo.com> wrote:
> 
> Thanks Sameer.
> 
> So does that mean that if the events keys are not same we cannot use the CEP pattern
match ?  What if events are coming from different sources and need to be correlated ?
> 
> Mans
> 
> 
> On Tuesday, August 9, 2016 9:40 AM, Sameer W <sameer@axiomine.com> wrote:
> 
> 
> Hi,
> 
> You will need to use keyBy operation first to get all the events you need monitored in
a pattern on the same node. Only then can you apply Pattern because it depends on the order
of the events (first, next, followed by). I even had to make sure that the events were correctly
sorted by timestamps to ensure that the first,next and followed by works correctly.
> 
> Sameer
> 
> On Tue, Aug 9, 2016 at 12:17 PM, M Singh <mans2singh@yahoo.com> wrote:
> Hey Folks:
> 
> I have a question about CEP processing in Flink - How does flink processing work when
we have multiple partitions in which the events used in the pattern sequence might be scattered
across multiple partitions on multiple nodes ?
> 
> Thanks for your insight.
> 
> Mans
> 
> 
> 

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