priyansndesai opened a new issue, #28832: URL: https://github.com/apache/beam/issues/28832
### What happened? While working on a Dataflow Runner V2 bug, we discovered that there is some extra sampling done by the SDK. Basically SDK side PCollection sampling is done on a per bundle basis, because we "technically" don't know if a given bundle is the only instance of this PCollection or not. But that ignores that SDKs re-use execution plans and naively just reads the first element of a pcollection in a bundle. This will lead to extra reads for pipelines with 1 key only, which is the hotkey. ### Issue Priority Priority: 3 (minor) ### Issue Components - [ ] Component: Python SDK - [X] Component: Java SDK - [ ] Component: Go SDK - [ ] Component: Typescript SDK - [ ] Component: IO connector - [ ] Component: Beam YAML - [ ] Component: Beam examples - [ ] Component: Beam playground - [ ] Component: Beam katas - [ ] Component: Website - [ ] Component: Spark Runner - [ ] Component: Flink Runner - [ ] Component: Samza Runner - [ ] Component: Twister2 Runner - [ ] Component: Hazelcast Jet Runner - [ ] Component: Google Cloud Dataflow Runner -- 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]
