GitHub user NicoK opened a pull request:
https://github.com/apache/flink/pull/5571
[FLINK-8759][network] preparations for the update of netty to version 4.0.56
## What is the purpose of the change
Based on the changes from #5570, this PR prepares a netty version bump by
circumventing a bug we had with the change from Netty 4.0.27 to 4.0.28 with the
old non-credit based flow control paths:
Versions >= 4.0.28 contain an improvement by Netty, which slices a Netty
buffer instead of doing a memory copy
(https://github.com/netty/netty/issues/3704) in the
`LengthFieldBasedFrameDecoder`. In some situations, this interacts badly with
our Netty pipeline leading to `OutOfMemory` errors.
With credit-based flow control this problem should not exist anymore which
is why we can use the original netty code there.
## Brief change log
- override `LengthFieldBasedFrameDecoder#extractFrame()` and implement two
different code paths depending on whether credit based flow control is on or not
## Verifying this change
This change is a trivial rework / code cleanup 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**
- The runtime per-record code paths (performance sensitive): **no** (only
per buffer)
- 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? **JavaDocs**
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/NicoK/flink flink-8759
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5571.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 #5571
----
commit 272899e01c2836a2a5b47958db7d9d9f6cbf471d
Author: Nico Kruber <nico@...>
Date: 2018-02-23T12:56:29Z
[FLINK-8768][network] Let NettyMessageDecoder inherit from
LengthFieldBasedFrameDecoder
This replaces one additional step from the pipeline and does not only remove
overhead there but also allows use to override the #extractFrame() method to
restore the old Netty 4.0.27 behaviour for non-credit based code paths which
had a bug with Netty >= 4.0.28 there (see FLINK-8759).
commit 11f673b415bce310cc2195fb6778051c095083fa
Author: Nico Kruber <nico@...>
Date: 2018-02-23T13:06:00Z
[FLINK-8759][network] preparations for the update of netty to version 4.0.56
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