Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@cassandra.apache.org
Message-ID: <10134988.22801291725972546.JavaMail.jira@thor>
Date: Tue, 7 Dec 2010 07:46:12 -0500 (EST)
From: "T Jake Luciani (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Subject: [jira] Updated: (CASSANDRA-1555) Considerations for larger bloom
 filters
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


     [ https://issues.apache.org/jira/browse/CASSANDRA-1555?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

T Jake Luciani updated CASSANDRA-1555:
--------------------------------------

    Attachment: 1555_v5.txt

Fixed the murur hash problem (the issue was with use of bytebuffers)
Re-factored the code a bit. Put hash32 and hash64 into MurmurHash class.

Overall I'm happy with this implementation, especially the sstable descriptor approach.

+1

Stu, I wasn't able to apply your latest patch for tests could you rebase against v5?


> Considerations for larger bloom filters
> ---------------------------------------
>
>                 Key: CASSANDRA-1555
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1555
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Stu Hood
>            Assignee: Ryan King
>             Fix For: 0.8
>
>         Attachments: 1555_v5.txt, addendum-to-1555.txt, cassandra-1555.tgz, CASSANDRA-1555v2.patch, CASSANDRA-1555v3.patch.gz, CASSANDRA-1555v4.patch.gz
>
>
> To (optimally) support SSTables larger than 143 million keys, we need to support bloom filters larger than 2^31 bits, which java.util.BitSet can't handle directly.
> A few options:
> * Switch to a BitSet class which supports 2^31 * 64 bits (Lucene's OpenBitSet)
> * Partition the java.util.BitSet behind our current BloomFilter
> ** Straightforward bit partitioning: bit N is in bitset N // 2^31
> ** Separate equally sized complete bloom filters for member ranges, which can be used independently or OR'd together under memory pressure.
> All of these options require new approaches to serialization.

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