Hi,

Yes, I tested all of them on spark 3.5.

Regards,
Andrzej


pon., 26 lut 2024 o 23:24 Mich Talebzadeh <mich.talebza...@gmail.com>
napisaƂ(a):

> Hi,
>
> These are all on spark 3.5, correct?
>
> Mich Talebzadeh,
> Dad | Technologist | Solutions Architect | Engineer
> London
> United Kingdom
>
>
>    view my Linkedin profile
> <https://www.linkedin.com/in/mich-talebzadeh-ph-d-5205b2/>
>
>
>  https://en.everybodywiki.com/Mich_Talebzadeh
>
>
>
> *Disclaimer:* The information provided is correct to the best of my
> knowledge but of course cannot be guaranteed . It is essential to note
> that, as with any advice, quote "one test result is worth one-thousand
> expert opinions (Werner  <https://en.wikipedia.org/wiki/Wernher_von_Braun>Von
> Braun <https://en.wikipedia.org/wiki/Wernher_von_Braun>)".
>
>
> On Mon, 26 Feb 2024 at 22:18, Andrzej Zera <andrzejz...@gmail.com> wrote:
>
>> Hey all,
>>
>> I've been using Structured Streaming in production for almost a year
>> already and I want to share the bugs I found in this time. I created a test
>> for each of the issues and put them all here:
>> https://github.com/andrzejzera/spark-bugs/tree/main/spark-3.5/src/test/scala
>>
>> I split the issues into three groups: outer joins on event time, interval
>> joins and Spark SQL.
>>
>> Issues related to outer joins:
>>
>>    - When joining three or more input streams on event time, if two or
>>    more streams don't contain an event for a join key (which is event time),
>>    no row will be output even if other streams contain an event for this join
>>    key. Tests that check for this:
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/OuterJoinTest.scala#L86
>>    and
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/OuterJoinTest.scala#L169
>>    - When joining aggregated stream with raw events with a stream with
>>    already aggregated events (aggregation made outside of Spark), then no row
>>    will be output if that second stream don't contain a corresponding event.
>>    Test that checks for this:
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/OuterJoinTest.scala#L266
>>    - When joining two aggregated streams (aggregated in Spark), no
>>    result is produced. Test that checks for this:
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/OuterJoinTest.scala#L341.
>>    I've already reported this one here:
>>    https://issues.apache.org/jira/browse/SPARK-45637 but it hasn't been
>>    handled yet.
>>
>> Issues related to interval joins:
>>
>>    - When joining three streams (A, B, C) using interval join on event
>>    time, in the way that B.eventTime is conditioned on A.eventTime and
>>    C.eventTime is also conditioned on A.eventTime, and then doing window
>>    aggregation based on A's event time, the result is output only after
>>    watermark crosses the window end + interval(A, B) + interval (A, C).
>>    However, I'd expect results to be output faster, i.e. when the watermark
>>    crosses window end + MAX(interval(A, B) + interval (A, C)). If our case is
>>    that event B can happen 3 minutes after event A and event C can happen 5
>>    minutes after A, there is no point to suspend reporting output for 8
>>    minutes (3+5) after the end of the window if we know that no more event 
>> can
>>    be matched after 5 min from the window end (assuming window end is based 
>> on
>>    A's event time). Test that checks for this:
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/IntervalJoinTest.scala#L32
>>
>> SQL issues:
>>
>>    - WITH clause (in contrast to subquery) seems to create a static
>>    DataFrame that can't be used in streaming joins. Test that checks for 
>> this:
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/SqlSyntaxTest.scala#L31
>>    - Two subqueries, each aggregating data using window() functio,
>>    breaks the output schema. Test that checks for this:
>>    
>> https://github.com/andrzejzera/spark-bugs/blob/abae7a3839326a8eafc7516a51aca5e0c79282a6/spark-3.5/src/test/scala/SqlSyntaxTest.scala#L122
>>
>> I'm a beginner with Scala (I'm using Structured Streaming with PySpark)
>> so won't be able to provide fixes. But I hope the test cases I provided can
>> be of some help.
>>
>> Regards,
>> Andrzej
>>
>

Reply via email to