[GitHub] flink pull request #5874: [FLINK-9076][network] reduce minimum number of flo...

[NicoK <gi...@git.apache.org>]

GitHub user NicoK opened a pull request:

    https://github.com/apache/flink/pull/5874

    [FLINK-9076][network] reduce minimum number of floating buffers to 0

    ## What is the purpose of the change
    
    Currently, floating buffers (per gate) are always required in case credit-based flow control is enabled. This, however, increases our minimum number of required network buffers.
    
    Instead, we should also work with a minimum of zero floating buffers and set the max to the configured value. This way, if there are not enough buffers, all `LocalBufferPool`s will at least share the available ones and not fail the job.
    
    ## Brief change log
    
    - make credit-based input gate buffer pools flexible (0 to `extraNetworkBuffersPerGate` buffers, depending on availability) - this is similar to the non-credit based code path
    - clarify the documentation of `taskmanager.network.memory.buffers-per-channel` in this regard
    
    ## Verifying this change
    
    This change added tests and can be verified as follows:
    
    - added unit tests inside `NetworkEnvironmentTest` to cover minimum and insufficient buffers scenarios for both credit-based and non-credit based
    - add a network end-to-end test to `StreamNetworkThroughputBenchmarkTest` covering minimum and insufficient buffers scenarios for default, i.e. credit-based, flow control
    
    ## 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** (but per-buffer - and too few buffers may degrade performance)
      - 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? **docs**


You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/NicoK/flink flink-9076

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/flink/pull/5874.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 #5874
    
----
commit 77896ab92114ecce6cf4549700dccb158e32d9f1
Author: Nico Kruber <ni...@...>
Date:   2018-04-18T15:04:38Z

    [FLINK-9208][tests] fix naming of StreamNetworkThroughputBenchmarkTest

commit c359f70db93508c25e1ceb880f858635f9b4d705
Author: Nico Kruber <ni...@...>
Date:   2018-04-06T09:15:10Z

    [FLINK-9076][network] reduce minimum number of floating buffers to 0

commit 60792fc1192260a6c443906f3ea6a175c8900787
Author: Nico Kruber <ni...@...>
Date:   2018-04-18T15:44:22Z

    [FLINK-9076][network] add network end-to-end test with minimum buffers

----


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[GitHub] flink issue #5874: [FLINK-9076][network] reduce minimum number of floating b...

[StephanEwen <gi...@git.apache.org>]

Github user StephanEwen commented on the issue:

    https://github.com/apache/flink/pull/5874
  
    This fix looks good, thanks!
    
    Merging this...


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[GitHub] flink pull request #5874: [FLINK-9076][network] reduce minimum number of flo...

[asfgit <gi...@git.apache.org>]

Github user asfgit closed the pull request at:

    https://github.com/apache/flink/pull/5874


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