[FLINK-815] Improve partitioning hash function

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: pre-apache-0.5, pre-apache, 0.6-incubating
• Labels: github-import
• Assignee: Unassigned
• Reporter: GitHub Import
• Created: 09/Jun/14 12:59
• Updated: 18/Jun/14 15:35
• Resolved: 18/Jun/14 15:35

Description

Right now, the partitioner (`OutputEmitter`) used directly the hash code produced by the partitioning elements. Types like `Integer` have very weak hash functions, so the hash partitioning is very susceptible to skew there.

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/815
Created by: StephanEwen
Labels: runtime,
Milestone: Release 0.6 (unplanned)
Created at: Wed May 14 21:40:36 CEST 2014
State: open