GWphua opened a new pull request, #18477: URL: https://github.com/apache/druid/pull/18477
### Description <!-- Describe the goal of this PR, what problem are you fixing. If there is a corresponding issue (referenced above), it's not necessary to repeat the description here, however, you may choose to keep one summary sentence. --> <!-- Describe your patch: what did you change in code? How did you fix the problem? --> <!-- If there are several relatively logically separate changes in this PR, create a mini-section for each of them. For example: --> This PR introduces a faster deserialization strategy when dealing with Intervals. #### Motivation Many Druid JSON payloads represent intervals as "YYYY-MM-DD'T'HH:mm:ss.SSSZ/YYYY-MM-DD'T'HH:mm:ss.SSSZ". The general parser behind Intervals.of(String) is flexible but performs extra work (branching, multiple format probes, allocations). This shows up as a hot spot in flame graphs, especially in streaming paths like JsonParserIterator. <img width="1920" height="958" alt="image" src="https://github.com/user-attachments/assets/fdb6fca4-f7a9-45bb-8f6c-bbd4ac901876"; /> #### Faster deserialization Added a fast-path deserializer for `Interval` that works with the common interval string representations, and falls back to `Intervals.of(String)` for non-matching inputs. We minimize work done per parse by: - Avoid checking if String can be converted into a `ReadableInterval` / `ReadWriteableInterval`. - Precompiled `DateTimeFormatter` replaces the flexible parser, with fixed chronology. - Avoid building 2 `DateTime` objects per parse. #### Benchmarks Added a benchmark to test performance of old (legacy) and new (optimized) implementation on 2 cases: 1. The expected interval format 2. The interval format which causes a fallback to the old implementation. (Suffix: Fallback) ``` Benchmark (numValues) Mode Cnt Score Error Units JodaIntervalDeserialization.deserializeLegacy 20000 avgt 30 21.466 ± 0.191 ms/op JodaIntervalDeserialization.deserializeLegacyFallback 20000 avgt 30 13.953 ± 0.249 ms/op JodaIntervalDeserialization.deserializeOptimized 20000 avgt 30 11.921 ± 0.082 ms/op JodaIntervalDeserialization.deserializeOptimizedFallback 20000 avgt 30 30.500 ± 0.304 ms/op ``` Benchmark shows an estimated 44% speed-up when working with the interval of format "YYYY-MM-DD'T'HH:mm:ss.SSSZ/YYYY-MM-DD'T'HH:mm:ss.SSSZ". However, for other formats, the fallback causes the performance to drop. #### Release note Speed up deserialization time of Intervals by >40% <hr> ##### Key changed/added classes in this PR * `processing/src/main/java/org/apache/druid/java/util/common/Intervals.java` * `processing/src/main/java/org/apache/druid/jackson/JodaStuff.java` * `processing/src/test/java/org/apache/druid/java/util/common/IntervalsTest.java` * `benchmarks/src/test/java/org/apache/druid/benchmark/JodaIntervalDeserialization.java` <hr> <!-- Check the items by putting "x" in the brackets for the done things. Not all of these items apply to every PR. Remove the items which are not done or not relevant to the PR. None of the items from the checklist below are strictly necessary, but it would be very helpful if you at least self-review the PR. --> This PR has: - [x] been self-reviewed. - [x] a release note entry in the PR description. - [x] added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links. - [x] added or updated version, license, or notice information in [licenses.yaml](https://github.com/apache/druid/blob/master/dev/license.md) - [x] added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader. - [x] added unit tests or modified existing tests to cover new code paths, ensuring the threshold for [code coverage](https://github.com/apache/druid/blob/master/dev/code-review/code-coverage.md) is met. - [x] been tested in a test Druid cluster. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
