[HADOOP-13599] s3a close() to be non-synchronized, so avoid risk of deadlock on shutdown

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.3
• Fix Version/s: 2.8.0, 3.0.0-alpha2
• Component/s: fs/s3
• Target Version/s: 2.8.0
• Hadoop Flags: Reviewed
• Assignee: Steve Loughran
• Reporter: Steve Loughran
• Created: 13/Sep/16 09:18
• Updated: 18/Oct/16 22:09
• Resolved: 28/Sep/16 23:33

Description

We've had a report of hive deadlocking on teardown, as a synchronous FS close was blocking shutdown threads, similar to HADOOP-3139

S3a close needs to be made non-synchronized. All we need is some code to prevent re-entrancy at the start; easily done