apache/beam

Can't use side inputs with Combine.PerKeyWithHotKeyFanout

Open

#20,637 opened on Jun 4, 2022

View on GitHub
 (3 comments) (0 reactions) (1 assignee)Java (4,097 forks)batch import
P3bugcoregood first issuejava

Repository metrics

Stars
 (7,313 stars)
PR merge metrics
 (Avg merge 6d) (243 merged PRs in 30d)

Description

PerKeyWithHotKeyFanout doesn't allow a user to specify a side input and access it in the CombineFn. When the function withHotKeyFanout is called, any sideinputs stored in the Combine.PerKey are dropped. (https://github.com/apache/beam/blob/master/sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/Combine.java#L1571): 


    public PerKeyWithHotKeyFanout<K, InputT, OutputT> withHotKeyFanout(
        SerializableFunction<?
super K, Integer> hotKeyFanout) {
      return new PerKeyWithHotKeyFanout<>(fn, fnDisplayData, hotKeyFanout);

   }

We would like to be able to use side inputs and hot key fanout.

Imported from Jira BEAM-11005. Original Jira may contain additional context. Reported by: miagilepner.

Contributor guide

Research direction
Examine the withHotKeyFanout method in Combine.java and ensure side inputs are passed correctly to the new PerKeyWithHotKeyFanout instance.
Tech stack
java
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaApache Beam
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70