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https://issues.apache.org/jira/browse/AURORA-1802?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15687519#comment-15687519
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Stephan Erb commented on AURORA-1802:
-------------------------------------
This is now on master
{code}
commit 320ee0810e95c79e2e3d31c9af041de7489c9f22
Author: Stephan Erb <s...@apache.org>
Date: Tue Nov 22 19:33:26 2016 +0100
Fix performance regression in AttributeAggregate performance.
This commit ensures AttributeAggregate will only be computed if needed by
limit constraints. This is the case in 0.16 but broken on master since the
introduction of scheduling attempts with multiple tasks.
In order to better model the latter this patch also updates the the
benchmarks to schedule multipe tasks per scheduleTask call.
Without the fix:
SchedulingBenchmarks.LimitConstraintMismatchSchedulingBenchmark.runBenchmark
thrpt 10 404.446 ± 31.252 ops/s
SchedulingBenchmarks.FillClusterBenchmark.runBenchmark thrpt 10 7.233 ±
3.058 ops/s
With the fix:
SchedulingBenchmarks.LimitConstraintMismatchSchedulingBenchmark.runBenchmark
thrpt 10 432.245 ± 16.963 ops/s
SchedulingBenchmarks.FillClusterBenchmark.runBenchmark thrpt 10 87.560
± 14.600 ops/s
Bugs closed: AURORA-1802
Reviewed at https://reviews.apache.org/r/53918/
src/jmh/java/org/apache/aurora/benchmark/SchedulingBenchmarks.java
| 13 ++++++++++---
src/main/java/org/apache/aurora/scheduler/filter/AttributeAggregate.java
| 34 ++++++++++++++++++++++++++++------
src/main/resources/org/apache/aurora/scheduler/storage/db/AttributeMapper.xml
| 1 -
3 files changed, 38 insertions(+), 10 deletions(-)
{code}
> AttributeAggregate slows down scheduling of jobs with many instances
> --------------------------------------------------------------------
>
> Key: AURORA-1802
> URL: https://issues.apache.org/jira/browse/AURORA-1802
> Project: Aurora
> Issue Type: Bug
> Components: Scheduler
> Reporter: Stephan Erb
> Fix For: 0.17.0
>
>
> The current implementation of
> [{{AttributeAggregate}}|https://github.com/apache/aurora/blob/f559e930659e25b3d7cacb7b845ebda50d18d66a/src/main/java/org/apache/aurora/scheduler/filter/AttributeAggregate.java]
> slows down scheduling of jobs with many instances. Interestingly, this is
> currently not visible in our job scheduling benchmark results as it only
> affects the benchmark setup time but not the measured part.
> {{AttributeAggregate}} relies on {{Suppliers.memoize}} to ensure that it is
> only computed once and only when necessary. This has probably been done
> because the factory
> [{{AttributeAggregate.getJobActiveState}}|https://github.com/apache/aurora/blob/f559e930659e25b3d7cacb7b845ebda50d18d66a/src/main/java/org/apache/aurora/scheduler/filter/AttributeAggregate.java#L56-L91]
> is slow.
> After some recent changes to schedule multiple task instances per scheduling
> round the aggregate is computed in each scheduling round via the call
> [{{resourceRequest.getJobState().updateAttributeAggregate(...)}}
> |https://github.com/apache/aurora/blob/f559e930659e25b3d7cacb7b845ebda50d18d66a/src/main/java/org/apache/aurora/scheduler/state/TaskAssigner.java#L173]
> in {{TaskAssigner}}. This means the expensive factory is called once per
> scheduling round.
> h3. Potential improvements
> * the current factory implementation performs one {{fetchTasks}} query
> followed by {{n}} distinct {{getHostAttributes}} queries. This could be
> reduced to a single SQL query.
> * the aggregate makes heavy use of {{ImmutableMultiset}} even though it is
> not immutable any more. There is potential room for improvement here.
> * The aggregate uses suppliers to perform a lazy instantiation even though
> its current usage is not lazy any more. We can either make the implementation
> eager, or ensure that the expensive part is only run when absolutely
> necessary.
> h3. Proof of concept
> * 4 mins 23.407 secs -- total runtime of {{./gradlew jmh
> -Pbenchmarks='SchedulingBenchmarks.InsufficientResourcesSchedulingBenchmark'}}
> * 2 mins 40.308 secs -- total runtime of {{./gradlew jmh
> -Pbenchmarks='SchedulingBenchmarks.InsufficientResourcesSchedulingBenchmark'}}
> with [{{resourceRequest.getJobState().updateAttributeAggregate(...)}}
> |https://github.com/apache/aurora/blob/f559e930659e25b3d7cacb7b845ebda50d18d66a/src/main/java/org/apache/aurora/scheduler/state/TaskAssigner.java#L173]
> commented out. This works as the call is not necessary when only a single
> instance is scheduled per scheduling round, as done in the benchmarks.
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