Description
Description of the hung DAG:
A DAG with 2 vertices. Map Vertex has 22k maps, downstream vertex Reduce has 1009 tasks. All tasks succeed but one, which hangs. This one task (attempt) is doing a local fetch from a node that (now) has a bad disk. It fails to fetch and reports to the AM for the offending input attempt identifiers. However the AM does not schedule a re-run as uniquefailedOutputReports size is 1 (since only this task attempt failed to fetch) and failure fraction is not met. The denominator for this fraction is the total number of tasks. That causes the re-run to never occur. This JIRA tracks the AM side of the change to alleviate this problem.
Attachments
Attachments
Issue Links
- is duplicated by
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TEZ-3198 Shuffle failures for the trailing task in a vertex are often fatal to the entire DAG
- Resolved