fix: Pull Queries: Avoids inefficient KsqlConfig copy with overrides #7193
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…s very inefficient
agavra
approved these changes
Mar 10, 2021
| // Do not set sessionConfig.getConfig to true! The copying is inefficient and slows down pull | ||
| // query performance significantly. Instead use PullPlannerOptions which check overrides | ||
| // deliberately. | ||
| final KsqlConfig ksqlConfig = sessionConfig.getConfig(false); |
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yikes. i wonder if there's a way for us to return a "view" when we call getConfig(true) instead of copying. This has bitten us twice 😢
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Yeah, I think rather than copy, we should more or less do what we do in this PR. Don't copy, but just check the overrides first.
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Description
The call to
sessionConfig.getConfig(true);copies fields of ksqlconfig in order to apply overrides. This is very inefficient, slowing pull query performance locally on my Mac from 10k qps for key lookups to 6k, a 40% reduction.I had made this change recently with #7006 so that the interpreter override would be available for pull queries. It had this unfortunate effect. The solution is to avoid the large copy and check overrides deliberately. We already have a pattern for this in
PullQueryConfigPlannerOptions.Testing done
Ran unit tests
Reviewer checklist