[SPARK-36389] Revert the change that accepts negative mapId in ShuffleBlockId

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.2.0
• Fix Version/s: 3.2.0, 3.3.0
• Component/s: Shuffle
• Assignee: Chandni Singh
• Reporter: Chandni Singh
• Created: 03/Aug/21 03:00
• Updated: 03/Aug/21 07:18
• Resolved: 03/Aug/21 06:35

Description

With SPARK-32922, we added a change that ShuffleBlockId can have a negative mapId. This was to support push-based shuffle where -1 as mapId indicated a push-merged block. However with SPARK-32923, a different type of BlockId was introduced - ShuffleMergedId, but reverting the change to ShuffleBlockId was missed.

Issue Links

• is related to: SPARK-30602 SPIP: Support push-based shuffle to improve shuffle efficiency
• links to: [Github] Pull Request #33616 (otterc)
• links to: [Github] Pull Request #33616 (otterc)