GitHub user sebastiansemmle opened a pull request:
https://github.com/apache/flink/pull/5245
[FLINK-8372] Fix NPEs when stopping worker nodes and adding tasks.
## What is the purpose of the change
Fix potential `NullPointerExceptions` when stopping worker nodes and adding
tasks.
[lgtm.com](https://lgtm.com) detected these two NPEs for `apache/flink`
which can be viewed
[here](https://lgtm.com/projects/g/apache/flink/alerts/?mode=tree&severity=error&rule=3960073)
## Brief change log
- The first commit fixes `YarnResourceManager.stopWorker()`, which, when
given a null reference, will attempt to obtain and print the resource id, which
in turn will fail. I opted to change the commit message as well in order to
accommodate for the missing id.
- The second commit fixes `TaskSlotTable.addTask()`, which, when given a
null reference will throw a `SlotNotFoundException`. However, since it attempts
to get an allocation id from that null reference, that exception will be
shadowed by an NPE.
## Verifying this change
*(Please pick either of the following options)*
This change is a trivial rework without any test coverage.
## 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 / don't know)
- The runtime per-record code paths (performance sensitive): (no / don't
know)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: (no / don't know)
- The S3 file system connector: (no / don't know)
## Documentation
- Does this pull request introduce a new feature? (no)
- If yes, how is the feature documented? (not applicable)
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/sebastiansemmle/flink fix-NPEs
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5245.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 #5245
----
commit 47bfeba899e54a3c4613c81a8a7a4c66b17f0cfd
Author: Sebastian Bauersfeld <sebastian@...>
Date: 2018-01-05T11:24:08Z
[FLINK-8372] Fix NullPointerException when stopping YarnWorkerNodes
commit 567c764eb4abef2d4847ebe946b4723878589b33
Author: Sebastian Bauersfeld <sebastian@...>
Date: 2018-01-05T11:24:42Z
[FLINK-8372] Fix NullPointerException when adding Tasks
----
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