[FLINK-16574] StreamingFileSink should rename files or fail if destination file already exists

• Type: Bug
• Status: Open
• Priority: Not a Priority
• Resolution: Unresolved
• Affects Version/s: 1.9.1
• Component/s: Connectors / FileSystem
• Labels: auto-deprioritized-major auto-deprioritized-minor

Environment

We're using Flink 1.9.1 on YARN with Horton HDP 2.7.3.

• Assignee: Unassigned
• Reporter: static-max
• Created: 12/Mar/20 17:56
• Updated: 17/Nov/21 22:38

Description

I switched from BucketingSink to StreamingFileSink so my state could not be restored after starting from a savepoint.

Upon start of the job there were already part-0-0 and part-0-1 files in the HDFS destination folder. The StreamingFileSink then creates a file like .part-0-0.inprogress.d1849354-39d4-4634-8fb3-dfb8e2083857. When the file is rolled Flink tries to rename it to part-0-0, but that file already exists. NameNode logs "WARN hdfs.StateChange (FSDirRenameOp.java:unprotectedRenameTo(174)) - DIR* FSDirectory.unprotectedRenameTo: failed to rename XXXX to XXXXbeca
use destination exists".

Flink does not care and creates a new file like .part-0-1.inprogress.d for the next bucket and the game continues until the part index counter is so high the file can be renamed. But now I'm left with a lot of .part-xxx.inprogress.xxx that I need to rename by hand if I don't want to lose the data.

 

I would expect Flink to either fail if the file cannot be renamed, or auto-rename it to filename that does not exists yet.

The same happens when not starting from a savepoint. IIRC the BucketingFileSink did not have this problem.