[
https://issues.apache.org/jira/browse/HBASE-1136?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
stack updated HBASE-1136:
-------------------------
Resolution: Fixed
Fix Version/s: 0.20.0
Status: Resolved (was: Patch Available)
Committed to TRUNK. Thanks for the patch Jonathan.
Please open a new patch against Hadoop with a patch for
src/core/org/apache/hadoop/util/bloom/HashFunction.java. HashFunction was
moved there by HADOOP-3063 (We'll move to using the hadoop versions in next
hbase). I can commit it after letting it air for a while in case objection.
> HashFunction inadvertently destroys some randomness
> ---------------------------------------------------
>
> Key: HBASE-1136
> URL: https://issues.apache.org/jira/browse/HBASE-1136
> Project: Hadoop HBase
> Issue Type: Bug
> Reporter: Jonathan Ellis
> Fix For: 0.20.0
>
> Attachments: hash.patch
>
>
> the code
> for (int i = 0, initval = 0; i < nbHash; i++) {
> initval = result[i] = Math.abs(hashFunction.hash(b, initval) %
> maxValue);
> }
> restricts initval for the next hash to the [0, maxValue) range of the hash
> indexes returned. This is suboptimal, particularly for larger nbHash and
> smaller maxValue. Instead, use:
> for (int i = 0, initval = 0; i < nbHash; i++) {
> initval = hashFunction.hash(b, initval);
> result[i] = Math.abs(initval) % maxValue;
> }
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
