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https://issues.apache.org/jira/browse/HADOOP-2654?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12560666#action_12560666
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Hadoop QA commented on HADOOP-2654:
-----------------------------------
-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12373592/counting-overflow-fourbit.patch
against trunk revision r613359.
@author +1. The patch does not contain any @author tags.
javadoc +1. The javadoc tool did not generate any warning messages.
javac +1. The applied patch does not generate any new compiler warnings.
findbugs -1. The patch appears to cause Findbugs to fail.
core tests -1. The patch failed core unit tests.
contrib tests -1. The patch failed contrib unit tests.
Test results:
http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1646/testReport/
Checkstyle results:
http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1646/artifact/trunk/build/test/checkstyle-errors.html
Console output:
http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1646/console
This message is automatically generated.
> CountingBloomFilter can overflow its storage
> --------------------------------------------
>
> Key: HADOOP-2654
> URL: https://issues.apache.org/jira/browse/HADOOP-2654
> Project: Hadoop
> Issue Type: Bug
> Components: contrib/hbase
> Reporter: Stu Hood
> Attachments: counting-overflow-fourbit.patch, counting-overflow.patch
>
>
> The org.onelab.filter.CountingBloomFilter implementation does not check the
> value of a bucket before incrementing/decrementing it. The buckets in a
> Counting Bloom filter must not be allowed to overflow, and if they reach
> their maximum value, they must not be allowed to decrement. This is the only
> way to preserve the assumptions of the filter (without larger buckets). See:
> http://en.wikipedia.org/wiki/Bloom_filter#Counting_filters
> Currently, if enough values hash to a bucket, the CountingBloomFilter may
> begin reporting false negatives when it wraps back around to 0.
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