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From "Jim Kellerman (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-2365) Result of HashFunction.hash() contains all identical values
Date Fri, 07 Dec 2007 18:07:50 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-2365?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12549498

Jim Kellerman commented on HADOOP-2365:


Do you think it is occurring for the same key?

If you could provide your initialization parameters and a test example, that would be very

> Result of HashFunction.hash() contains all identical values
> -----------------------------------------------------------
>                 Key: HADOOP-2365
>                 URL: https://issues.apache.org/jira/browse/HADOOP-2365
>             Project: Hadoop
>          Issue Type: Bug
>          Components: contrib/hbase
>    Affects Versions: 0.16.0
>            Reporter: Andrzej Bialecki 
>            Assignee: Jim Kellerman
>             Fix For: 0.16.0
>         Attachments: hash-v1.patch, patch.txt, patch.txt
> There is a small bug in HashFunction:112 - initvalue should be changed between the loop
iterations in order to spread the hash values over the whole allowed range. Instead the current
code uses a fixed initvalue = 0, which gives all identical hash values in the result array.
As a result, BloomFilter-s have extremely high rate of false positives.

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