Ben Roling created HADOOP-16085:
-----------------------------------

             Summary: S3Guard: use object version to protect against 
inconsistent read after replace/overwrite
                 Key: HADOOP-16085
                 URL: https://issues.apache.org/jira/browse/HADOOP-16085
             Project: Hadoop Common
          Issue Type: Improvement
            Reporter: Ben Roling


Currently S3Guard doesn't track S3 object versions.  If a file is written in 
S3A with S3Guard and then subsequently overwritten, there is no protection 
against the next reader seeing the old version of the file instead of the new 
one.

It seems like the S3Guard metadata could track the S3 object version.  When a 
file is created or updated, the object version could be written to the S3Guard 
metadata.  When a file is read, the read out of S3 could be performed by object 
version, ensuring the correct version is retrieved.

I don't have a lot of direct experience with this yet, but this is my 
impression from looking through the code.  My organization is looking to shift 
some datasets stored in HDFS over to S3 and is concerned about this potential 
issue as there are some cases in our codebase that would do an overwrite.

I imagine this idea may have been considered before but I couldn't quite track 
down any JIRAs discussing it.  If there is one, feel free to close this with a 
reference to it.

Am I understanding things correctly?  Is this idea feasible?  Any feedback that 
could be provided would be appreciated.  We may consider crafting a patch.



--
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

Reply via email to