GitHub user fhueske opened a pull request:
https://github.com/apache/flink/pull/5742
[FLINK-9031] Fix DataSet Union operator translation bug.
## What is the purpose of the change
- Fixes a bug reported in
[FLINK-9031](https://issues.apache.org/jira/browse/FLINK-9031)
- Union nodes had a partitioning strategy on the outgoing channel, that was
(intentionally) not translated by the `JobGraphGenerator` because the
`JobGraphGenerator` assumed that Union nodes would always have outgoing FORWARD
strategies.
- Not translating the partitioning resulted in an incorrect result because
data was not correctly distributed.
## Brief change log
- Add a check in `JobGraphGenerator` to fail if a union node with
non-FORWARD outgoing strategy is found.
- Add a pre-optimization plan traversal that fixes the strategy of union
outputs to FORWARD.
- Add a test based on a simplified version of the reported program.
## Verifying this change
- Run the added test.
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): **no**
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: **no**
- The serializers: **no**
- The runtime per-record code paths (performance sensitive): **no**
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: **no**
- The S3 file system connector: **no**
## Documentation
- Does this pull request introduce a new feature? **no**
- If yes, how is the feature documented? **n/a**
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/fhueske/flink dataSetUnionBug
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5742.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 #5742
----
commit 3939f06bacaf1595844de56fe58651732b89592e
Author: Fabian Hueske <fhueske@...>
Date: 2018-03-21T19:54:05Z
[FLINK-9031] Fix DataSet Union operator translation bug.
- Adds a pass over the pre-optimized plan that fixes the output strategy of
union nodes to FORWARD.
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