Yue Ma created FLINK-26941:
------------------------------
Summary: Support Pattern end with notFollowedBy with window
Key: FLINK-26941
URL: https://issues.apache.org/jira/browse/FLINK-26941
Project: Flink
Issue Type: Improvement
Components: Library / CEP
Affects Versions: 1.14.4
Reporter: Yue Ma
Fix For: 1.14.4
Currently a pattern sequence cannot end in notFollowedBy() in Flink CEP. But in
fact, this requirement exists in many scenarios. As mentioned in the following
tickets：
https://issues.apache.org/jira/browse/FLINK-16010
https://issues.apache.org/jira/browse/FLINK-9431
Unfortunately, these tickets are not active for a long time.But we still think
this is an important feature for Flink CEP, so we would like to share our
implementation.
if we want to find the users who created an order but didn't pay in 10 minutes.
We could code like this:
Pattern.begin('create').notFollowedBy('pay_order').withIn(10min)
If we receive the create event but don't receive the pay event within 10
minutes, then the match will be successful.
The idea of implementation is basically the same as the design of FLINK-16010.
A Pending State is introduced to represent the state of waiting for a timeout,
and there is a take edge between the Pending node and the Stop node.
When advanceTime, if it is found that the pending node has timed out, then
extract the timeout sequence and output it normally as successed matched
sequence.
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
