[HADOOP-14467] S3Guard: Improve FNFE message when opening a stream

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: HADOOP-13345
• Component/s: fs/s3
• Target Version/s: HADOOP-13345
• Assignee: Aaron Fabbri
• Reporter: Aaron Fabbri
• Created: 30/May/17 21:04
• Updated: 09/Aug/17 17:37
• Resolved: 09/Aug/17 16:06

Description

Following up on the discussion on HADOOP-13345, because S3Guard can serve getFileStatus() from the MetadataStore without doing a HEAD on S3, a FileNotFound error on a file due to S3 GET inconsistency does not happen on open(), but on the first read of the stream. We may add retries to the S3 client in the future, but for now we should have an exception message that indicates this may be due to inconsistency (assuming it isn't a more straightforward case like someone deleting the object out from under you).

This is expected to be a rare case, since the S3 service is now mostly consistent for GET.

Issue Links

• is related to: HADOOP-14468 S3Guard: make short-circuit getFileStatus() configurable