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Ben Roling commented on HADOOP-15625: ------------------------------------- Thanks for your help and improvements on this Steve! I'll work on the TODO list today. bq. should we have an option to require version checking? Yeah, probably. I had second thoughts about my code that was only logging a warning when object versioning was disabled on the bucket. I'll add something for this. bq. Style checking. Javadocs are critical as java 8 needs the "." at the end. Line length-wise, we like to keep down to nearly 80, due to the goal of side-by-side diff checking. I know, it'd be good to move on a some point, but until then... I'll try to fix any of these issues. I did get a sense maybe some of my lines were too long. bq. Docs. Something to discuss the option. Will do. bq. core-site.xml: Add the default options there (etag @ warn?) alongside the other fs.s3a options. Yep, I'll add those. I was originally thinking etag-server as the default, but I suppose that could be considered an incompatible change. I guess folks will just have to learn to enable this feature. bq. Maybe: have the InconsistentAmazonS3Client simulate version inconsistency. But with the isolated change tracking, I don't see the point in that Yeah, I'm not sure it is necessary either. > S3A input stream to use etags to detect changed source files > ------------------------------------------------------------ > > Key: HADOOP-15625 > URL: https://issues.apache.org/jira/browse/HADOOP-15625 > Project: Hadoop Common > Issue Type: Sub-task > Components: fs/s3 > Affects Versions: 3.2.0 > Reporter: Brahma Reddy Battula > Assignee: Brahma Reddy Battula > Priority: Major > Attachments: HADOOP--15625-006.patch, HADOOP-15625-001.patch, > HADOOP-15625-002.patch, HADOOP-15625-003.patch, HADOOP-15625-004.patch, > HADOOP-15625-005.patch, HADOOP-15625-006.patch > > > S3A input stream doesn't handle changing source files any better than the > other cloud store connectors. Specifically: it doesn't noticed it has > changed, caches the length from startup, and whenever a seek triggers a new > GET, you may get one of: old data, new data, and even perhaps go from new > data to old data due to eventual consistency. > We can't do anything to stop this, but we could detect changes by > # caching the etag of the first HEAD/GET (we don't get that HEAD on open with > S3Guard, BTW) > # on future GET requests, verify the etag of the response > # raise an IOE if the remote file changed during the read. > It's a more dramatic failure, but it stops changes silently corrupting things. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org