GitHub user StephanEwen opened a pull request:
https://github.com/apache/flink/pull/1175
[FLINK-2753] [streaming] [api breaking] Add first parts of new window API
for key grouped windows
This follows the API design outlined in
https://cwiki.apache.org/confluence/display/FLINK/Streams+and+Operations+on+Streams
This change is API breaking because it adds new generic type parameters to
Java and Scala classes, breaking binary compatibility.
This new API uses in the background the dedicated operators added in a
previous pull request, which improved robustness and performance and fixed
several correctness bugs.
### New window API
```java
DataStream<MyType> stream = ...;
stream.keyBy("id")
.window(Time.of(5, SECONDS))
.reduceWindow( (a, b) -> a.fuse(b) )
```
The Pull Request also introduces the first parts of defining the programs
Time characteristic on the StreamExecutionEnvironment:
- *Processing time*
- *Ingestion time*
- *Event time*
Eventually, the other window mechanisms should be replaced by this:
- Windows per key are covered in this new mechanism
- Global windows (global parallel discretization) were decided to be
dropped for safety and replaced by single-group windows (non parallel) with
possible parallel pre-aggregation (for aligned time windows)
### Follow-up
- Adding the generic window operator based on generic policies (adaption
of the current windowing system by @aljoscha ), see
https://issues.apache.org/jira/browse/FLINK-2677
- Automatically activating and configuring Watermark generation at the
data sources
- Adding a dedicated Event Time Window operator
- Adding the single-group non-parallel windows
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/StephanEwen/incubator-flink windows
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/1175.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #1175
----
commit 61c3666a272413940e65a2195b87c7472a8e8806
Author: Stephan Ewen <se...@apache.org>
Date: 2015-09-23T10:05:54Z
[FLINK-2753] [streaming] [api breaking] Add first parts of new window API
for key grouped windows
This follows the API design outlined in
https://cwiki.apache.org/confluence/display/FLINK/Streams+and+Operations+on+Streams
This is API breaking because it adds new generic type parameters to Java
and Scala classes, breaking binary compatibility.
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