[SPARK-18337] Memory Sink should be able to recover from checkpoints in Complete OutputMode

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.1
• Fix Version/s: 2.0.3, 2.1.0
• Component/s: Structured Streaming
• Assignee: Burak Yavuz
• Reporter: Burak Yavuz
• Created: 07/Nov/16 22:27
• Updated: 15/Nov/16 21:42
• Resolved: 15/Nov/16 21:42

Description

Memory sinks are not meant to be fault tolerant, but there are certain cases, where it would be nice that it can recover from checkpoints. In cases where you may use a scalable StateStore in StructuredStreaming (when you have an aggregation), and you add a filter based on a key or value in your state, it's nice to be able to continue from where you left off after failures.

For correctness reasons, the output will ONLY be correct in Complete mode, so we could support that.

Issue Links

• is related to: SPARK-17921 checkpointLocation being set in memory streams fail after restart. Should fail fast
• links to: [Github] Pull Request #15801 (brkyvz)