[Bug] Long tail tasks in the Write Stage retry phase results in data loss.
- Dominant language
- Java
- Stars
- 454
- Forks
- 172
- Avg merge
- 5d 17h
- Merged PRs (30d)
- 5
Description
### Code of Conduct
- [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)
### Search before asking
- [X] I have searched in the [issues](https://github.com/apache/incubator-uniffle/issues?q=is%3Aissue) and found no similar issues.
### Describe the bug
During the Write Stage retry phase, the MapOutputTrackerMaster clears the MapStatus corresponding to the shuffleId on the Driver side. However, when a large number of partitions are encountered, the MapStatus may not be completely cleared. Retry at the Stage, the task becomes less, resulting in data loss. At present, I encountered a 40000 Partition, resulting in data loss.
Below is a screenshot of my problem:

### Affects Version(s)
0.10.0
### Uniffle Server Log Output
_No response_
### Uniffle Engine Log Output
_No response_
### Uniffle Server Configurations
_No response_
### Uniffle Engine Configurations
_No response_
### Additional context
_No response_
### Are you willing to submit PR?
- [X] Yes I am willing to submit a PR!
Contributor guide
Research direction
Start at MapOutputTrackerMaster and trace how MapStatus is cleared during the Write Stage retry phase, especially with a shuffle containing 40,000 partitions. Reproduce the retry with a large partition count and verify that all required MapStatus data remains available and that the retried stage completes without data loss.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java, spark
- Domain
- distributed-systems
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100