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Date: Fri, 28 Jun 2013 21:59:21 +0000 (UTC)
From: "Brandon Williams (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Message-ID: <JIRA.12539513.1327345889152.186220.1372456761125@arcas>
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Subject: [jira] [Commented] (CASSANDRA-3772) Evaluate Murmur3-based
 partitioner
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    [ https://issues.apache.org/jira/browse/CASSANDRA-3772?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13695845#comment-13695845 ] 

Brandon Williams commented on CASSANDRA-3772:
---------------------------------------------

It doesn't really matter if you can create M3 collisions, we only use it to find the node to store the data, the key sent and stored is still the actual key, not the hash.  If you knew a token in the cluster the worst you could do is cause some (probably imperceptible) imbalance.
                
> Evaluate Murmur3-based partitioner
> ----------------------------------
>
>                 Key: CASSANDRA-3772
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3772
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: Core
>            Reporter: Jonathan Ellis
>            Assignee: Pavel Yaskevich
>             Fix For: 1.2.0 beta 1
>
>         Attachments: 0001-CASSANDRA-3772.patch, 0001-CASSANDRA-3772-Test.patch, CASSANDRA-3772-v2.patch, CASSANDRA-3772-v3.patch, CASSANDRA-3772-v4.patch, hashed_partitioner_3.diff, hashed_partitioner.diff, MumPartitionerTest.docx, try_murmur3_2.diff, try_murmur3.diff
>
>
> MD5 is a relatively heavyweight hash to use when we don't need cryptographic qualities, just a good output distribution.  Let's see how much overhead we can save by using Murmur3 instead.

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