[CASSANDRA-2975] Upgrade MurmurHash to version 3

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.2.0 beta 1
• Labels: lhf
• Assignee: Vijay
• Reporter: Brian Lindauer

Authors

Vijay

Reviewers

Pavel Yaskevich

• Created: 30/Jul/11 04:43
• Updated: 16/Apr/19 09:32
• Resolved: 16/Mar/12 23:26

Description

MurmurHash version 3 was finalized on June 3. It provides an enormous speedup and increased robustness over version 2, which is implemented in Cassandra. Information here:

http://code.google.com/p/smhasher/

The reference implementation is here:
http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp?spec=svn136&r=136

I have already done the work to port the (public domain) reference implementation to Java in the MurmurHash class and updated the BloomFilter class to use the new implementation:

https://github.com/lindauer/cassandra/commit/cea6068a4a3e5d7d9509335394f9ef3350d37e93

Apart from the faster hash time, the new version only requires one call to hash() rather than 2, since it returns 128 bits of hash instead of 64.

Issue Links

• is depended upon by: CASSANDRA-3772 Evaluate Murmur3-based partitioner