GitHub user tillrohrmann opened a pull request:
https://github.com/apache/flink/pull/6067
[FLINK-9427] Fix registration and request slot race condition in
TaskExecutor
## What is the purpose of the change
This commit fixes a race condition between the TaskExecutor and the
ResourceManager. Before,
it could happen that the ResourceManager sends requestSlots message before
the TaskExecutor
registration was completed. Due to this, the TaskExecutor did not have all
information it needed
to accept task submissions.
The problem was that the TaskExecutor sent the SlotReport at registration
time. Due to this, t
he SlotManager could already assign these slots to pending slot requests.
With this commit, the
registration protocol changes such that the TaskExecutor first registers at
the ResourceManager
and only after completing this step, it will announce the available slots
to the SlotManager.
cc @GJL
## Brief change log
- Changed the `TaskExecutor` `ResourceManager` registration protocol to
announce the available slots after the completion of the registration
- Hardened the `TaskExecutor#requestSlot` to only accept the call if there
is an established connection to a `ResourceManager`
## Verifying this change
- Added `SlotManagerTest#testSlotRequestFailure`
- Added `TaskExecutorTest#testIgnoringSlotRequestsIfNotRegistered`,
`testReconnectionAttemptIfExplicitlyDisconnected`, `testInitialSlotReport` and
`testInitialSlotReportFailure`
## 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): (n)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: (yes)
- The S3 file system connector: (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/tillrohrmann/flink fixTaskExecutorRegistration
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/6067.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 #6067
----
commit 4b4d82cc5a3bb9694fd19a37c21345cbe7928962
Author: Till Rohrmann <trohrmann@...>
Date: 2018-05-23T16:50:27Z
[FLINK-9427] Fix registration and request slot race condition in
TaskExecutor
This commit fixes a race condition between the TaskExecutor and the
ResourceManager. Before,
it could happen that the ResourceManager sends requestSlots message before
the TaskExecutor
registration was completed. Due to this, the TaskExecutor did not have all
information it needed
to accept task submissions.
The problem was that the TaskExecutor sent the SlotReport at registration
time. Due to this, t
he SlotManager could already assign these slots to pending slot requests.
With this commit, the
registration protocol changes such that the TaskExecutor first registers at
the ResourceManager
and only after completing this step, it will announce the available slots
to the SlotManager.
----
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