hfukada opened a new pull request, #15049: URL: https://github.com/apache/druid/pull/15049
### Description - Based off of http://www.vldb.org/pvldb/vol12/p2195-masson.pdf and uses the corresponding https://github.com/DataDog/sketches-java library - contains tests for post building and using aggregation/post aggregation. - New aggregator: `ddSketch` - New post aggregators: `quantileFromDDSketch` and `quantilesFromDDSketch` #### Release note New: `druid-ddsketch` Extension. DDSketches can be built off of raw numeric data or merged from other DDSketches that have been preaggregated. DDSketches are then used to calculate quantiles with relative error guarantees with bounded space. ##### Key changed/added classes in this PR * `DDSketchAggregatorFactory`: Sets defaults up for aggregators. notably relativeError = 0.01 and numBins = 1000 * `DDSketchAggregator`: Does the accepting of new values and merging of other DDSketches. * `DDSketchBufferAggregator`: same as above but using the buffer. * `DDSketchComplexMetricSerde`: registers the serde * `DDSketchObjectStrategy`: Strategy for managing the objects/serialization/deserialization * `DDSketchToQuantilePostAggregator`: Sets up the postAggregator `quantileFromDDSketch` * `DDSketchToQuantilesPostAggregator`: Sets up the postAggregator `quantilesFromDDSketch` * `DDSketchUtils`: Utility functions around serialization/deserialization using `protobuf` This PR has: - [x] been self-reviewed. - [x] using the [concurrency checklist](https://github.com/apache/druid/blob/master/dev/code-review/concurrency.md) (Remove this item if the PR doesn't have any relation to concurrency.) - [x] added documentation for new or modified features or behaviors. - [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] added integration tests. - [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]
