How does Voldemort compare to Cassandra?

Question

I'm not talking about size of community and only want to hear from people who have actually used both.

Especially I'm interested in:

How they dynamically scale when adding and removing nodes
Query performance
How they scale when adding nodes (linear)?
Write speed

Niiice! How does a character from Harry Potter compares to a Greek goddess :)... Now that's interesting. — Anton Gogolev, Feb 12 '10 at 13:56
@Anton: +1 to your comment except that she was not a goddess :) — Quassnoi, Feb 12 '10 at 13:59
**Sex appeal:** Cassandra is way hotter than Voldemort. Compare http://en.wikipedia.org/wiki/Voldemort http://en.wikipedia.org/wiki/Cassandra **Community size:** Voldemort tends to have a smaller, more dedicated, quite violence-prone community. Followers of Cassandra (warning about horrible things to come) are more widespread. — Pekka, Feb 12 '10 at 14:00
@Vinko, of course this is programming realted, check the links in the question. — Pekka, Feb 12 '10 at 14:05
@Pekka: I see my comment wasn't perceived as intended. I would have directly voted for closing instead of commenting about it if I truly believed what I wrote. — Vinko Vrsalovic, Feb 12 '10 at 14:11
Subjective and Argumentative. There's no criteria for comparison. That's like Comparing C# to Java. The answer is *It depends*. — George Stocker, Feb 12 '10 at 14:26
This is a valid question as these are both quite recent products and have alot of hype around them, and I need to know people's experience with dynamic adding/removal of nodes and things like that, and rebalancing of data, which varies "hugely" on alot of these products. I'm not looking for a religious war so please stop fighting. — yazz.com, Feb 12 '10 at 17:00
And I want to hear from people who have actually used "both" products, just so that I only hear from people who know what they are talking about. If it means the question goes unanswered then so be it. — yazz.com, Feb 12 '10 at 17:00

score 36 · Accepted Answer · answered Feb 16 '10 at 14:31

Voldemort's support for adding nodes was just added recently (this month). So I would expect Cassandra's to be more robust given the longer time to cook and a larger community testing.

Both are fast (> 10k ops/s per machine). Because of their storage designs, I would expect Cassandra to be faster at writes, and Voldemort to be faster at reads. I would also expect Cassandra's performance to degrade less as the amount of data per node increases. And of course if you need more than just a key/value data model Cassandra's ColumnFamily model wins.

I don't know of any head-to-head benchmarks since the one done for NoSQL SF last June, which found Cassandra to be somewhat faster at whatever workload mix he was using. (The "vpork" talk from http://blog.oskarsson.nu/2009/06/nosql-debrief.html) 8 months is an eternity with projects under this much development, though.

At last, someone who knows what they are talking about. Thanks jbellis, I thought this would never get answered! :) — yazz.com, Feb 16 '10 at 14:33

score 8 · Answer 2 · answered Jul 16 '10 at 18:57

Some additional comments:

Regarding write speed, Cassandra should be faster -- it is designed to be faster to write than read (you can avoid immediate disk hit for writes due to specialized way storage is done)

But main difference I think is actually not performance but feature set: Voldemort is strictly a key/value store (currently anyway), whereas Cassandra can offer range queries (with order-preserving partitioner), and bit more structure around data (column families etc). Former is an important consideration for design; latter IMO less so, you can always structure BLOB data on client side.

It's also important to note that cassandra supports bloomfilters, which allow to index rows by column presence inside a column family. It's very unlikely that you would achiveve something like that with client blob programming. — Jens, May 22 '13 at 16:58

How does Voldemort compare to Cassandra?

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