nyingping opened a new pull request, #36737:
URL: https://github.com/apache/spark/pull/36737
<!--
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.
-->
Fix bug that Generate wrong time window when (timestamp-startTime) %
slideDuration < 0
The original time window generation rule
```
lastStart <- timestamp - (timestamp - startTime + slideDuration) %
slideDuration
```
change like this
```
remainder <- (timestamp - startTime) % slideDuration
lastStart <-
if (remainder < 0) timestamp - remainder - slideDuration
else timestamp - remainder
```
reference:
[https://github.com/apache/flink/pull/18982](https://github.com/apache/flink/pull/18982)
### 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.
-->
Since the generation strategy of the sliding window in PR
[#35362](https://github.com/apache/spark/pull/35362) is changed to the current
one, and that leads to a new problem.
A window generation error occurs when the time required to process the
recorded data is negative and the modulo value between the time and window
length is less than 0. In the current test cases, this bug does not thorw up.
[ test("negative
timestamps")](https://github.com/apache/spark/blob/master/sql/core/src/test/scala/org/apache/spark/sql/DataFrameTimeWindowingSuite.scala#L299)
```
val df1 = Seq(
("1970-01-01 00:00:02", 1),
("1970-01-01 00:00:12", 2)).toDF("time", "value")
val df2 = Seq(
(LocalDateTime.parse("1970-01-01T00:00:02"), 1),
(LocalDateTime.parse("1970-01-01T00:00:12"), 2)).toDF("time", "value")
Seq(df1, df2).foreach { df =>
checkAnswer(
df.select(window($"time", "10 seconds", "10 seconds", "5 seconds"),
$"value")
.orderBy($"window.start".asc)
.select($"window.start".cast(StringType),
$"window.end".cast(StringType), $"value"),
Seq(
Row("1969-12-31 23:59:55", "1970-01-01 00:00:05", 1),
Row("1970-01-01 00:00:05", "1970-01-01 00:00:15", 2))
)
}
```
The timestamp of the above test data is not negative, and the value modulo
the window length is not negative, so it can be passes the test case.
An exception occurs when the timestamp becomes something like this.
```
val df3 = Seq(
("1969-12-31 00:00:02", 1),
("1969-12-31 00:00:12", 2)).toDF("time", "value")
val df4 = Seq(
(LocalDateTime.parse("1969-12-31T00:00:02"), 1),
(LocalDateTime.parse("1969-12-31T00:00:12"), 2)).toDF("time", "value")
Seq(df3, df4).foreach { df =>
checkAnswer(
df.select(window($"time", "10 seconds", "10 seconds", "5 seconds"),
$"value")
.orderBy($"window.start".asc)
.select($"window.start".cast(StringType),
$"window.end".cast(StringType), $"value"),
Seq(
Row("1969-12-30 23:59:55", "1969-12-31 00:00:05", 1),
Row("1969-12-31 00:00:05", "1969-12-31 00:00:15", 2))
)
}
```
run and get unexpected result:
```
== Results ==
!== Correct Answer - 2 == == Spark Answer - 2 ==
!struct<> struct<CAST(window.start AS
STRING):string,CAST(window.end AS STRING):string,value:int>
![1969-12-30 23:59:55,1969-12-31 00:00:05,1] [1969-12-31
00:00:05,1969-12-31 00:00:15,1]
![1969-12-31 00:00:05,1969-12-31 00:00:15,2] [1969-12-31
00:00:15,1969-12-31 00:00:25,2]
```
### 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.
-->
Add new unit test.
**benchmark result**
oldlogic[#18364](https://github.com/apache/spark/pull/18364) VS 【fix
version】
```
Running benchmark: tumbling windows
Running case: old logic
Stopped after 407 iterations, 10012 ms
Running case: new logic
Stopped after 615 iterations, 10007 ms
Java HotSpot(TM) 64-Bit Server VM 1.8.0_181-b13 on Windows 10 10.0
Intel64 Family 6 Model 158 Stepping 10, GenuineIntel
tumbling windows: Best Time(ms) Avg Time(ms)
Stdev(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------------------------------
old logic 17 25
9 580.1 1.7 1.0X
new logic 15 16
2 680.8 1.5 1.2X
Running benchmark: sliding windows
Running case: old logic
Stopped after 10 iterations, 10296 ms
Running case: new logic
Stopped after 15 iterations, 10391 ms
Java HotSpot(TM) 64-Bit Server VM 1.8.0_181-b13 on Windows 10 10.0
Intel64 Family 6 Model 158 Stepping 10, GenuineIntel
sliding windows: Best Time(ms) Avg Time(ms)
Stdev(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------------------------------
old logic 1000 1030
19 10.0 100.0 1.0X
new logic 668 693
21 15.0 66.8 1.5X
```
Fixed version than PR [#38069](https://github.com/apache/spark/pull/35362)
lost a bit of the performance.
--
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-unsubscr...@spark.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
