Csaba Ringhofer has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/20612 )

Change subject: IMPALA-3825: Delegate runtime filter aggregation to some 
executors
......................................................................


Patch Set 13:

(2 comments)

http://gerrit.cloudera.org:8080/#/c/20612/10/be/src/runtime/runtime-filter-bank.cc
File be/src/runtime/runtime-filter-bank.cc:

http://gerrit.cloudera.org:8080/#/c/20612/10/be/src/runtime/runtime-filter-bank.cc@139
PS10, Line 139: AllocateScratchBloomFilter
> Filter aggregation can happen sometime later after all fragment start. I'm
If the reservation is claimed, then it is considered a fatal error if 
allocating memory (up to the reservation) fails. 
https://github.com/apache/impala/blob/aeb9a8206028b68833ce6e49421990854f0c8ba4/be/src/runtime/bufferpool/buffer-pool.h#L77

Other queries should be only able to use the memory for buffers that can be 
dropped (e.g. spilled)


http://gerrit.cloudera.org:8080/#/c/20612/10/be/src/runtime/runtime-filter-bank.cc@722
PS10, Line 722: result_filter->SetFilter(B
> Agree. Done.
Few things about this:
- it is not clear to me whether this was a real bug, so whether not setting it 
could lead to dropping rows incorrectly

- it would be nice to have a test for this scenario. Adding a delay/jitter 
debug action + low runtime_filter_wait_time_ms should be able to lead to the 
situation where all/some remote filters do not arrive in time. Looked around 
for tests like this and I couldn't find any that intentionally creates late 
filters. A cancellation related test seems to something like this: 
https://github.com/apache/impala/blob/b03e8ef95c856f499d17ea7815831e30e2e9f467/tests/query_test/test_runtime_filters.py#L110
 I am ok moving test creation to a follow up Jira if it seems complicated.

- do we actually need to run CombinePeerAndLocalUpdates? it seems unnecessary 
as the filter is all true - I don't think that we should put effort in 
optimizing this case, but a comment could mention that this is done for 
simplicity



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I11d38ed0f223d6e5b32a19ebe725af7738ee4ab0
Gerrit-Change-Number: 20612
Gerrit-PatchSet: 13
Gerrit-Owner: Riza Suminto <[email protected]>
Gerrit-Reviewer: Abhishek Rawat <[email protected]>
Gerrit-Reviewer: Csaba Ringhofer <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Kurt Deschler <[email protected]>
Gerrit-Reviewer: Michael Smith <[email protected]>
Gerrit-Reviewer: Riza Suminto <[email protected]>
Gerrit-Comment-Date: Wed, 13 Dec 2023 10:25:23 +0000
Gerrit-HasComments: Yes

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