hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "HBase Review Board (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HBASE-2531) 32-bit encoding of regionnames waaaaaaayyyyy too susceptible to hash clashes
Date Sun, 30 May 2010 00:15:38 GMT

    [ https://issues.apache.org/jira/browse/HBASE-2531?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12873348#action_12873348
] 

HBase Review Board commented on HBASE-2531:
-------------------------------------------

Message from: "Kannan Muthukkaruppan" <kannan@facebook.com>





> 32-bit encoding of regionnames waaaaaaayyyyy too susceptible to hash clashes
> ----------------------------------------------------------------------------
>
>                 Key: HBASE-2531
>                 URL: https://issues.apache.org/jira/browse/HBASE-2531
>             Project: HBase
>          Issue Type: Bug
>            Reporter: stack
>            Assignee: Kannan Muthukkaruppan
>            Priority: Blocker
>             Fix For: 0.21.0
>
>         Attachments: HBASE-2531_v2.patch
>
>
> Kannan tripped over two regionnames that hashed the same:
> Here is code demo'ing that his two names hash the same:
> {code}
> package org;
> import org.apache.hadoop.hbase.util.Bytes;
> import org.apache.hadoop.hbase.util.JenkinsHash;
> public class Testing {
>   public static void main(final String [] args) {
>     System.out.println(encodeRegionName(Bytes.toBytes("test1,6838000000,1273541236167")));
>     System.out.println(encodeRegionName(Bytes.toBytes("test1,0520100000,1273541610201")));
>   }
>   /**
>    * @param regionName
>    * @return the encodedName
>    */
>   public static int encodeRegionName(final byte [] regionName) {
>     return Math.abs(JenkinsHash.getInstance().hash(regionName, regionName.length, 0));
>   }
> }
> {code}
> Need new encoding mechanism.  Will need to migrate old regions to new schema.

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


Mime
View raw message