CockroachDB: A Scalable, Geo-Replicated, Transactional Datastore

https://github.com/cockroachdb/cockroach?hn=true

by sokrates • 12 years ago

77 55 12 years ago

limsup• 12 years ago

I assume it's called this because a cockroach can supposedly survive a nuclear attack. But it's a bad name. It does not invoke good feelings.

oalders• 12 years ago

It's memorable and I think the meaning is pretty clear, but it did make me shudder as well. :)

taternuts• 12 years ago

I have to agree - maybe 'RoachDB' would be better

morgante• 12 years ago

I like RoachDB. The idea is still there, but it's a little more fun.

jc_dntn• 12 years ago

I prefer "CockDB".

donut2d• 12 years ago

Have to agree. I have so many bad feelings attached to cockroaches that just seeing the name makes me sick to my stomach.

gresrun2• 12 years ago

Trademark considerations aside, I'd vote for TwinkieDB

Andrex• 12 years ago

Or even better, TwinkDB.

notduncansmith2• 12 years ago

Maybe "Caracha" or "CarachaDB"? As in, "La Cucaracha". Still there, but veiled enough that it won't make people uncomfortable just on hearing it.

jmspring• 12 years ago

I like the name. I had a good idea of the goals when I saw that bit of the title without reading the rest...

increment_i• 12 years ago

Gotta agree. Cringe inducing name when you first hear it, but I imagine it would become less so as you worked with it more and more. You'd be desensitized to it after a while I'd imagine.

rb2k_• 12 years ago

How would one communicate with this DB?

I'd love to see some API examples.

Meai• 12 years ago

Also benchmarks comparing it to RethinkDb, Mongodb, and sql examples (supposedly this is NewSQL, how much SQL does it even support?) These questions are important

teraflop3• 12 years ago

Here's the transactional key/value store API: http://godoc.org/github.com/cockroachdb/cockroach/kv

And an RDBMS-like layer on top of it: http://godoc.org/github.com/cockroachdb/cockroach/structured

warfangle2• 12 years ago

Riak, when you use LevelDB behind it, certainly has indexes. As many as you want (within reason), through secondary indexes[0]. While it doesn't have joins specifically, you can link data blobs and walk the links[1]. For when that isn't quite enough, you can always perform a compiled erlang map reduce across a given dataset[2].

I don't quite see how CockroachDB offers anything Riak doesn't.

Riak, while not offering true locking transactions (it doesn't look like CockroachDB does either - imagine how long it would take to perform a locked transaction across sixteen data centers in as many countries, two of which have gone dark due to power outages and giant robots), offers you the option of resolving data version conflicts when you read the record[3]. (ed. Many times if doing a partial update of a record, you need to read before writing anyway. This resolves a conflict before you write to a potentially conflicted record chain. Typically this is done with a pre-commit hook. [4])

(ed.: The major differences seem to stem from the snapshotting system CDB uses to provide external consistency across data centers. This comes at a (potentially huge, especially if two clusters lose connection with each other but not with clients) delay in write verification.

Riak, on the other hand, would still allow writes - and would resolve any conflicts when the datacenters connect again. It's a hairy problem to fix, especially in a general manner.

It all depends on what kind of data you're storing.)

0. http://docs.basho.com/riak/latest/dev/using/2i/

1. http://docs.basho.com/riak/latest/dev/using/link-walking/

2. http://docs.basho.com/riak/latest/dev/using/mapreduce/

3. http://docs.basho.com/riak/latest/theory/concepts/Vector-Clo...

4. http://docs.basho.com/riak/latest/dev/using/commit-hooks/

itsnotvalid• 12 years ago

Multi Data Center Replication doesn't come in the free-lunch-pack. To get that with Riak, you probably need to downpay $6000 for getting that license for a node. So if you have two geolocations for your data, it would be at least $12000 for a minimal setup.

Of course for people looking at the usage for this, money is not the major issue.

warfangle2• 12 years ago

Very good point.

maaku3• 12 years ago

Fully ACID transactions is a big deal.

dgrnbrg• 12 years ago

They're based on Raft--that's not a consensus protocol that's designed for multi-datacenter operations. I suspect you'll have reliability and throughput issues fairly quickly, just as you see with multi-datacenter zookeeper.

The solution Google uses for this kind of problem: multidatacenter transactions are rare, so they're not optimized for latency (instead for reliability), and they tend to use 2PC, as it's easier to get right with unpredictable WAN latencies.

rch3• 12 years ago

Riak will have strongly consistent buckets in 2.0+, which pretty much takes care of the cases in which I'd need guarantees for data in this storage model.

rdtsc• 12 years ago

What is your comment on the "No availability or weak consistency with datacenter failure" part?

Is that referring to Riak's cross data center replication (enterprise feature). I guess for regular case (non-enterprise version) it is true, as it is not possible to specifically assign ring sections to data centers?

hendzen• 12 years ago

Simple, CockroachDB is a CP system, while Riak is an AP system.

If you need multi-key ACID transactions, and can tolerate potential downtime in the event that some partition loses a majority of its Raft replicas, you might want to use CockroachDB.

If high availability is a concern, and you can tolerate the occasional data conflict in the case of incomparable vector clocks due to writes accepted during a network partition, or, if your schema can be modeled with CRDTs (LWW register, PN counter, Union-Set, etc), you might want to use Riak.

nawitus3• 12 years ago

How does it handle replication and the resulting conflicts?

teraflop3• 12 years ago

It uses strongly consistent replication, so there are no conflicts.

nawitus3• 12 years ago

So it doesn't support "proper" replication, e.g. the kind where the databases are not connected 100% the time perfectly? And I wonder how they can prevent conflicts due to latency.. Even if there's a 50ms latency, is the other database going to wait for 50ms between every write or something?

candybar• 12 years ago

As for the name, which I agree is problematic as is, how about EntomoDB for entomos (insect)?

Edit: It's not problematic if success is not an objective. But if it is, choosing a name with such strong established negative connotations is not wise.

maaku3• 12 years ago

How is the name problematic? I knew exactly what they were saying and why when I saw it. If it were me I would have shortened it to RoachDB, but that's just marketing.

iLoch• 12 years ago

I agree it would probably be a good idea to chop off the cock.

enraged_camel• 12 years ago

>How is the name problematic?

Most people are disgusted by cockroaches. I think that's a good enough reason to change the name, at least if you want the product to be taken seriously.

jacquesm2• 12 years ago

That's a funny name for a database. At least you'll know that whoever uses it does not use it for its buzzword value.

How will this handle partitioning of the network? The readme has a lot of info about bits of the far-flung cluster failing but nothing about how it would deal with the whole cluster being chopped up into roughly equal halves. That's one of the harder problems to deal with for solutions aimed at this space.

simpsond• 12 years ago

Cockroaches are resilient and hard to kill.

jacquesm2• 12 years ago

I'm aware of that.

orasis• 12 years ago

Change the name. I get the joke, but it has an emotionally negative connotation that bosses will hate.

logn• 12 years ago

CoachDB ?

dmarlow2• 12 years ago

CroachDB

aerialfish• 12 years ago

Agreed. Take out the 'roach' part and watch its popularity skyrocket.

dmarlow2• 12 years ago

nice

pnathan• 12 years ago

Terrible name.

bdevine2• 12 years ago

That's the first thing I thought. If anybody from the team is looking, how about something like BlattoDB[0]?

[0] http://en.m.wikipedia.org/wiki/Blattaria

notduncansmith2• 12 years ago

Sounds a lot like "blotto", which is the last state I want my DB in.

dang• 12 years ago

Given that most of the comments are merely about the name, and that the author has implied that the software doesn't work [1], it seems there's little to discuss here. We're going to demote this submission [2].

1. https://twitter.com/andybons/status/472458545154494465. The answer to that question, btw, is yes. Reposts of stories that have had significant attention are treated as dupes for about a year.

2. That's not a criticism of the submitter. We want to see original work on HN. But there ought to be some substance to it, as well as to the resulting discussion.

CockroachDB: A Scalable, Geo-Replicated, Transactional Datastore

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