[HIVE-17113] Duplicate bucket files can get written to table by runaway task

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0
• Component/s: Query Processor
• Assignee: Jason Dere
• Reporter: Jason Dere
• Created: 17/Jul/17 22:06
• Updated: 22/May/18 23:58
• Resolved: 31/Jul/17 23:23

Description

Saw a table get a duplicate bucket file from a Hive query. It looks like the following happened:

1. Task attempt A_0 starts,but then stops making progress
2. The job was running with speculative execution on, and task attempt A_1 is started
3. Task attempt A_1 finishes execution and saves its output to the temp directory.
5. A task kill is sent to A_0, though this does appear to actually kill A_0
6. The job for the query finishes and Utilities.mvFileToFinalPath() calls Utilities.removeTempOrDuplicateFiles() to check for duplicate bucket files
7. A_0 (still running) finally finishes and saves its file to the temp directory. At this point we now have duplicate bucket files - oops!
8. Utilities.removeTempOrDuplicateFiles() moves the temp directory to the final location, where it is later moved to the partition directory.

Issue Links

• relates to: HIVE-17813 hive.exec.move.files.from.source.dir does not work with partitioned tables
• relates to: HIVE-17963 Fix for HIVE-17113 can be improved for non-blobstore filesystems