GitHub user StephanEwen opened a pull request:
https://github.com/apache/flink/pull/5166
[FLINK-8264] [core] Add 'scala.' to the 'parent-first' classloading patterns
## What is the purpose of the change
Adding `scala.` to the "parent-first-patterns" makes sure that Scala
classes are not duplicated through "child-first" classloading when users
accidentally package the Scala Library into the application jar.
Since Scala classes traverse the boundary between core and user space, they
should never be duplicated.
## Brief change log
- Adds `scala.` to the default value of
`classloader.parent-first-patterns`.
## Verifying this change
This change can be verified as follows:
- Create a very simple quickstart Scala project using a Scala lambda for
a filter function (`_ => true`).
- Package it such that the Scala library is in the user code jar
- Without the fix, you get a weird class cast exception during
deserialization, with this fix, everything is fine.
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): (yes / **no)**
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: (yes / **no**)
- The serializers: (yes / **no** / don't know)
- The runtime per-record code paths (performance sensitive): (yes /
**no** / don't know)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: (yes / **no** / don't know)
- The S3 file system connector: (yes / **no** / don't know)
## Documentation
- Does this pull request introduce a new feature? (yes / **no**)
- If yes, how is the feature documented? (**not applicable** / docs /
JavaDocs / not documented)
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/StephanEwen/incubator-flink 8264_master
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5166.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 #5166
----
commit 7587b519eff3cfce847fa9619c3bed29e1f740bb
Author: Stephan Ewen <se...@apache.org>
Date: 2017-12-14T12:50:39Z
[FLINK-8264] [core] Add 'scala.' to the 'parent-first' classloading
patterns.
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