You are viewing a plain text version of this content. The canonical link for it is here.
Posted to reviews@spark.apache.org by GitBox <gi...@apache.org> on 2022/10/10 22:27:40 UTC
[GitHub] [spark] sunchao opened a new pull request, #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
sunchao opened a new pull request, #38196:
URL: https://github.com/apache/spark/pull/38196
<!--
Thanks for sending a pull request! Here are some tips for you:
1. If this is your first time, please read our contributor guidelines: https://spark.apache.org/contributing.html
2. Ensure you have added or run the appropriate tests for your PR: https://spark.apache.org/developer-tools.html
3. If the PR is unfinished, add '[WIP]' in your PR title, e.g., '[WIP][SPARK-XXXX] Your PR title ...'.
4. Be sure to keep the PR description updated to reflect all changes.
5. Please write your PR title to summarize what this PR proposes.
6. If possible, provide a concise example to reproduce the issue for a faster review.
7. If you want to add a new configuration, please read the guideline first for naming configurations in
'core/src/main/scala/org/apache/spark/internal/config/ConfigEntry.scala'.
8. If you want to add or modify an error type or message, please read the guideline first in
'core/src/main/resources/error/README.md'.
-->
### What changes were proposed in this pull request?
<!--
Please clarify what changes you are proposing. The purpose of this section is to outline the changes and how this PR fixes the issue.
If possible, please consider writing useful notes for better and faster reviews in your PR. See the examples below.
1. If you refactor some codes with changing classes, showing the class hierarchy will help reviewers.
2. If you fix some SQL features, you can provide some references of other DBMSes.
3. If there is design documentation, please add the link.
4. If there is a discussion in the mailing list, please add the link.
-->
This PR fixes a performance regression issue when one side of a join uses `HashPartitioning` with `ShuffleExchange` while the other side uses `SinglePartition`. In this case, Spark will re-shuffle the side with `HashPartitioning` and both sides will end up with only a single partition. This could hurt query performance a lot if the side with `HashPartitioning` contains a lot of input data.
### Why are the changes needed?
<!--
Please clarify why the changes are needed. For instance,
1. If you propose a new API, clarify the use case for a new API.
2. If you fix a bug, you can clarify why it is a bug.
-->
After SPARK-35703, when Spark sees that one side of the join has `ShuffleExchange` (meaning it needs to be shuffled anyways), and the other side doesn't, it'll try to avoid shuffling the side without `ShuffleExchange`. For instance:
```
ShuffleExchange(HashPartition(200)) <-> HashPartition(150)
```
will be converted into
```
ShuffleExchange(HashPartition(150)) <-> HashPartition(150)
```
However, when the side without `ShuffleExchange` is `SinglePartition`, like the following:
```
ShuffleExchange(HashPartition(150)) <-> SinglePartition
```
Spark will also do the same which causes the left-hand side to only use one partition. This can hurt job parallelism dramatically, especially when using DataSource V2, since `SinglePartition` is used by the V2 scan. On the other hand, it seems DataSource V1 won't be impacted much as it always report `UnknownPartitioning` in this situation.
### Does this PR introduce _any_ user-facing change?
<!--
Note that it means *any* user-facing change including all aspects such as the documentation fix.
If yes, please clarify the previous behavior and the change this PR proposes - provide the console output, description and/or an example to show the behavior difference if possible.
If possible, please also clarify if this is a user-facing change compared to the released Spark versions or within the unreleased branches such as master.
If no, write 'No'.
-->
No.
### How was this patch tested?
<!--
If tests were added, say they were added here. Please make sure to add some test cases that check the changes thoroughly including negative and positive cases if possible.
If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future.
If tests were not added, please describe why they were not added and/or why it was difficult to add.
If benchmark tests were added, please run the benchmarks in GitHub Actions for the consistent environment, and the instructions could accord to: https://spark.apache.org/developer-tools.html#github-workflow-benchmarks.
-->
Added new unit tests in `EnsureRequirementsSuite`.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] wangyum commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
wangyum commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1279636319
Merged to master and branch-3.3
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] sunchao commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
sunchao commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1274853785
cc @cloud-fan @c21 @viirya @dongjoon-hyun @huaxingao
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] c21 commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
c21 commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1275742743
LGTM, thanks for the fix.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] dongjoon-hyun commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
dongjoon-hyun commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1275295888
Also, cc @mridulm and @tgravescs , too
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] wangyum closed pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
wangyum closed pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
URL: https://github.com/apache/spark/pull/38196
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] sunchao commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
sunchao commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1279764239
Thanks @wangyum @bryanck @zhengruifeng @dongjoon-hyun @huaxingao @viirya @c21 !
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] wangyum commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
wangyum commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1276199767
cc @cloud-fan
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] sunchao commented on a diff in pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
sunchao commented on code in PR #38196:
URL: https://github.com/apache/spark/pull/38196#discussion_r992455054
##########
sql/core/src/test/scala/org/apache/spark/sql/execution/PlannerSuite.scala:
##########
@@ -277,7 +277,7 @@ class PlannerSuite extends SharedSparkSession with AdaptiveSparkPlanHelper {
val numExchanges = collect(plan) {
case exchange: ShuffleExchangeExec => exchange
}.length
- assert(numExchanges === 3)
+ assert(numExchanges === 5)
Review Comment:
Restored the test to the previous state as in Spark 3.2. Query plan:
After this PR:
```
AdaptiveSparkPlan isFinalPlan=false
+- SortMergeJoin [key#220], [key#222], Inner
:- SortMergeJoin [key#13], [key#220], Inner
: :- Sort [key#13 ASC NULLS FIRST], false, 0
: : +- Exchange hashpartitioning(key#13, 5), ENSURE_REQUIREMENTS, [plan_id=133]
: : +- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#13, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false, true) AS value#14]
: : +- Scan[obj#12]
: +- Sort [key#220 ASC NULLS FIRST], false, 0
: +- Exchange hashpartitioning(key#220, 5), ENSURE_REQUIREMENTS, [plan_id=134]
: +- GlobalLimit 10, 0
: +- Exchange SinglePartition, ENSURE_REQUIREMENTS, [plan_id=129]
: +- LocalLimit 10
: +- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#220, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false, true) AS value#221]
: +- Scan[obj#218]
+- Sort [key#222 ASC NULLS FIRST], false, 0
+- Exchange hashpartitioning(key#222, 5), ENSURE_REQUIREMENTS, [plan_id=142]
+- GlobalLimit 3, 0
+- Exchange SinglePartition, ENSURE_REQUIREMENTS, [plan_id=138]
+- LocalLimit 3
+- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#222, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false, true) AS value#223]
+- Scan[obj#219]
```
Before this PR:
```
AdaptiveSparkPlan isFinalPlan=false
+- SortMergeJoin [key#220], [key#222], Inner
:- SortMergeJoin [key#13], [key#220], Inner
: :- Sort [key#13 ASC NULLS FIRST], false, 0
: : +- Exchange SinglePartition, ENSURE_REQUIREMENTS, [plan_id=134]
: : +- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#13, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false, true) AS value#14]
: : +- Scan[obj#12]
: +- Sort [key#220 ASC NULLS FIRST], false, 0
: +- GlobalLimit 10, 0
: +- Exchange SinglePartition, ENSURE_REQUIREMENTS, [plan_id=129]
: +- LocalLimit 10
: +- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#220, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false, true) AS value#221]
: +- Scan[obj#218]
+- Sort [key#222 ASC NULLS FIRST], false, 0
+- GlobalLimit 3, 0
+- Exchange SinglePartition, ENSURE_REQUIREMENTS, [plan_id=138]
+- LocalLimit 3
+- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#222, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false, true) AS value#223]
+- Scan[obj#219]
```
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] zhengruifeng commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
zhengruifeng commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1274061615
Looks reasonable to me
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
[GitHub] [spark] cloud-fan commented on pull request #38196: [SPARK-40703][SQL] Introduce shuffle on SinglePartition to improve parallelism
Posted by GitBox <gi...@apache.org>.
cloud-fan commented on PR #38196:
URL: https://github.com/apache/spark/pull/38196#issuecomment-1283252896
late LGTM. I think this is good to fix the perf regression, but we probably need a better design to fix similar problems. What if the other side is `HashPartitioning(2)`? The parallelism can still be too low. We need some heuristic or cost model to make a better decision here.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org