GitHub user NicoK opened a pull request:
https://github.com/apache/flink/pull/4733
[FLINK-7701][network] really fix watermark configuration order this time
## What is the purpose of the change
Netty (in the version we use) only allows setting high and low watermarks
after another but complains about invalid values and ignores them, e.g. if the
new high watermark is less than the (old) low watermark. This makes it
important to get the order of the configuration options right. #4391 fixed this
for large memory segment sizes (where the low watermark would have been larger
than the high watermark) but broke the of small segment sizes which lead to the
scenario outlined above. This should fix both.
## Brief change log
- configure `ServerBootstrap` based on the current values vs. the defaults
(those are unfortunately not exposed, so we need to inline the current one)
- adapt `NettyServerLowAndHighWatermarkTest` to reflect both use cases
(outlined above)
## Verifying this change
This change added tests and can be verified as follows:
- adapted `NettyServerLowAndHighWatermarkTest` to cover both high and low
segment sizes
- as before, no test for the `KvStateServer` since watermarks cannot be
configured there (make sure it works the same way, though!)
## 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)
## 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/NicoK/flink flink-7701
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/4733.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 #4733
----
commit 509a3267d4613f48100a1e813ac49847e8bd5494
Author: Nico Kruber <n...@data-artisans.com>
Date: 2017-09-27T11:44:35Z
[FLINK-7701][network] really fix watermark configuration order this time
FLINK-7258 fixed this for large memory segment sizes but broke it for small
ones. This should fix both.
FYI: Newer Netty versions actually circumvent the problem by allowing to set
both watermarks at the same time.
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