[FLUME-2320] Deadlock in DatasetSink

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.0
• Fix Version/s: 1.5.0
• Component/s: Sinks+Sources
• Assignee: Ryan Blue
• Reporter: Ryan Blue
• Created: 12/Feb/14 02:39
• Updated: 04/May/14 04:18
• Resolved: 27/Feb/14 19:07

Description

Lines 251-252 in the DatasetSink are a potential deadlock: if the transaction throws an exception, then the writer lock is not released, but the same thread tries to lock in the error handling.

While the simplest solution is to move those two lines inside the try/finally statement, I think we can actually remove the lock completely by reverting to the original version that rolled the files in the process() method. The original concern about that design was that there needs to be some guarantee that all files will be rolled. Because the SinkRunner has a max backoff, there is a guaranteed maximum amount of time between calls to process.