scheduler: Tasks with a desired state < RUNNING should count #1980
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Currently, the scheduler counts tasks on each node with desired state of RUNNING. This works fine for sequential updates, but in parallel updates, the scheduler can assign tasks unfairly, because the ones it already assigned may not have changed their desired state to RUNNING yet. In an update with unlimited parallelism, all the tasks may end up on the same node, even when there are multiple nodes that can accomodate the tasks. Fix this by considering all tasks with a desired state at or below RUNNING to be active. For example, tasks at READY should be seen the same way as RUNNING tasks by the scheduler - they were assigned to that node and will eventually start running. Signed-off-by: Aaron Lehmann <[email protected]>
Codecov Report
@@ Coverage Diff @@
## master #1980 +/- ##
==========================================
- Coverage 53.69% 53.59% -0.11%
==========================================
Files 109 109
Lines 18919 18919
==========================================
- Hits 10158 10139 -19
- Misses 7526 7543 +17
- Partials 1235 1237 +2Continue to review full report at Codecov.
|
|
LGTM |
|
LGTM Cherry pick? |
|
Cherry picked |
This was referenced Feb 23, 2017
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Currently, the scheduler counts tasks on each node with desired state of
RUNNING. This works fine for sequential updates, but in parallel
updates, the scheduler can assign tasks unfairly, because the ones it
already assigned may not have changed their desired state to RUNNING
yet. In an update with unlimited parallelism, all the tasks may end up
on the same node, even when there are multiple nodes that can accomodate
the tasks.
Fix this by considering all tasks with a desired state at or below
RUNNING to be active. For example, tasks at READY should be seen the
same way as RUNNING tasks by the scheduler - they were assigned to that
node and will eventually start running.
cc @jlhawn @aluzzardi @dongluochen