[ 
https://issues.apache.org/jira/browse/HADOOP-1385?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12497041
 ] 

Owen O'Malley commented on HADOOP-1385:
---------------------------------------

I think it wouldn't be a good test case to make sure the collision happens if 
the fifth bytes are different. If at some point we xor all of the words 
together, that would be ok and should cause regression failures.

> MD5Hash has a bad hash function
> -------------------------------
>
>                 Key: HADOOP-1385
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1385
>             Project: Hadoop
>          Issue Type: Bug
>          Components: io
>    Affects Versions: 0.12.3
>            Reporter: Owen O'Malley
>         Assigned To: Owen O'Malley
>             Fix For: 0.13.0
>
>         Attachments: 1385.patch
>
>
> The MD5Hash class has a really bad hash function, that will cause most most 
> md5s to hash to 0xFFFFFFxx leaving only the low order byte as meaningful. The 
> problem comes from the automatic sign extension when promoting from byte to 
> int.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to