MongoDB or CouchDB - fit for production? [closed]

Question

I'm the CTO of 10gen (developers of MongoDB) so I'm a bit biased, but I also manage a few sites that are using MongoDB in production.

businessinsider has been using mongo in production for over a year now. They are using it for everything from users and blog posts, to every image on the site.

shopwiki is using it for a few things including real time analytics and a caching layer. They are doing over 1000 writes per second to a fairly large database.

If you go to the mongodb Production Deployments page you'll see some people who are using mongo in production.

If you have any questions about the scale or scope of production deployments, post on our user list and we'll be more than happy to help.

The BBC and meebo.com use CouchDB in production and so does one of my clients. Here is a list of other people using Couch: CouchDB in the wild

The major challenge is to know how to organize your documents and stop thinking in terms of relational data.

SourceForge uses MongoDB. See this presentation or read here.

We are running CouchDB as a replacemant for MySQL for our shops (70.0000 items/shop, a total of 4 million attributes of all items, cross connections between items).

Our goals were:

1. Easy replication from a master-db to several clients with different documents.

2. Fast pre-calculated data like "how many parts do I have with this attribute and that filter, fitting to those conditions"

facts:

1. Our shops are now running much faster than with MySQL (and mysql-database needed additionaly 1-3 days of pre-calculating (so updating was twice a month), making the data ready for product counting and filtering, CouchDB needs 5 hours, so we could update product data every night)
2. Setting up (filtered) data distribution & backups to the shop nodes is fast and easy

but also:

1. Understanding map/reduce and the limits of not having joins is quite hard
2. No operation on data like "delete where" or "update where" without external programs
3. Replication works well, unless there is a problem; then it's really hard to find out what was the reason (for beginners)
4. The installation of CouchDB without binaries (yes there are a some in the wild, but not for every OS/version) could be hard, if you are not a Linux geek. But the CouchDB Community is helpful (#couchdb), and luckily there are companies out there (cloudant, iriscouch) that offer services from free to big business.
5. CouchDB is moving forward, so there are a lot of changes (improvements) going on that might change they way you work. But basic things remain stable.

As a result: MySQL as a database for data creation and maintaining is reliable and easy to understand and handle. I think we will not change this. But I also don't want to miss the power of CouchDB views and the ease of replication setup.

Production couches sometimes caused trouble after months of work due to misconfiguration and forgotten logrotates (view building takes too long or hangs, replication stops), but never lost data, and always could be easily reset.

I am using CouchDB in production. Currently it stores all those 'optional' fields that weren't in the original DB schema. And right now I am thinking about moving all data to CouchDB.

It's quite a risky step, I admit. Firstly, because it's not v1.0 yet. And secondly, because it is drivespace-hungry. By my calculations, CouchDB file (with indexes) is ~30 times larger than MySQL database with the same rows. But I am pretty sure it will work out just fine.

CouchDB 0.11 (released at the end of March) is a feature-freeze release for 1.0. This means we'll be maintaining compatibility with the current API for 1.0, so now is a good time to take another look at CouchDB if you haven't in a while.

The CouchDB 0.11 source code release is available here. There are binary installers and other goodies linked here.

I don't know anything about MongoDB, but from the CouchDB FAQ:

Is CouchDB Ready for Production?

Yes, see InTheWild for a partial list of projects using CouchDB. Another good overview is CouchDB Case Studies

Also, some links:

• Re: Current CouchDB state?
• SimpleDB, CouchDB and Other "NEW" Data Stores - Feedback