Github user kl0u commented on a diff in the pull request:
https://github.com/apache/flink/pull/4041#discussion_r119596846
--- Diff: docs/dev/libs/cep.md ---
@@ -874,3 +1141,19 @@ val alerts = patternStream.select(createAlert(_)))
{% endhighlight %}
</div>
</div>
+
+## Migrating from an older Flink version
+
+The CEP library in Flink-1.3 ships with a number of new features which
have led to some changes in the API. Here we
+describe the changes that you need to make to your old CEP jobs, in order
to be able to run them with Flink-1.3. After
+making these changes and recompiling your job, you will be able to resume
its execution from a savepoint taken with the
+old version of your job, *i.e.* without having to re-process your past
data.
+
+The changes required are:
+
+1. Change your conditions (the ones in the `where(...)` clause) to extend
the `SimpleCondition` class instead of
+implementing the `FilterFunction` interface.
+
+2. Change your functions provided as arguments to the `select(...)` and
`flatSelect(...)` methods to expect a list of
+events associated with each state (`List` in `Java`, `Iterable` in
`Scala`). This is because with the addition of
+the looping states, multiple input events can much a single (looping)
state.
--- End diff --
hehe good "cats" (catch) :P
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
