Read the Hacker News thread about Coinbase.

Money is going missing. Transactions have been delayed for days and, in some cases, over a week. Even amounts already in BTC aren’t leaving the system.

The (snarky) comment is that Coinbase is a bank built on MongoDB.

Emin Gün Sirer

Original title and link: Does Anyone Know What’s Going on at Coinbase? - a Bank on MongoDB (NoSQL database©myNoSQL)

via: https://news.ycombinator.com/item?id=5427985

Bradford Stephens (CEO Drawn to Scale):

Today, we’re announcing that we’ve ported MongoDB onto Spire as a platform. What this means is:

1. You can easily scale your MongoDB cluster to 200+ TB
2. You don’t need to change a line of code in your app to make it scale
3. You can use ANSI SQL (yes, joins), Mongo queries, and Hadoop on the same data.

Just a couple of thoughts:

1. the push of NoSQL databases to get SQL support is growing extremely fast. But I still doubt this is happening thanks to the advantages of SQL, but more due to the 30 years of investments in the SQL ecosystem.
2. I don’t agree with Bradford’s “MongoQL is also great because unlike SQL, there is only one flavor”. As far as I can tell, MongoDB comes with 3 flavors of queries: the object-based query language, the aggregation framework (a combination of object-based QL and pipelining) and the Javascript-based MapReduce
3. last but not least, what are Ryan Rawson’s thoughts about Drawn to Scale going Mongo.

Original title and link: Drawn to Scale Announces Spire for Mongo (NoSQL database©myNoSQL)

via: http://drawntoscale.com/announcing-spire-for-mongo/

MongoDB 2.4 is out:

Highlights of MongoDB 2.4 include:

• Hash-based Sharding
• Capped Arrays
• Text Search (Beta)
• Geospatial Enhancements
• Faster Counts
• Working Set Analyzer
• V8 JavaScript engine

Original title and link: MongoDB 2.4 Released: Hash-Based Sharding, Geo Enhancements, Text Search (NoSQL database©myNoSQL)

via: http://blog.mongodb.org/post/45754637343/mongodb-2-4-released

Kristina Chodorow¹ shared a good list of tests to put a MongoDB cluster through:

Here are some exercises to battle-test your MongoDB instance before going into production. You’ll need a Database Master (aka DM) to make bad things happen to your MongoDB install and one or more players to try to fix it.

Netflix is using a series of tools that perform similar tests against their Cassandra clusters. With a small twist: they are run against the production clusters.

Original title and link: Battle-Test Your MongoDB Cluster (NoSQL database©myNoSQL)

via: http://architects.dzone.com/articles/databases-and-dragons-battle

MongoDB 2.2 introduced thetouch command, which loads data from the data storage layer into memory. The touch command will load a collection’s documents, indexes or both into memory. This can be ideal to preheat a newly started server, in order to avoid page faults and slow performance once the server is brought into production. You can also use this when adding a new secondary to an existing replica set to ensure speedy subsequent reads.

I could see how this command could be useful for a caching system, but I haven’t seen it in any database. It’s probably a workaround for the memory mapped files mechanism used by MongoDB’s persistence.

Original title and link: MongoDB Touch Command (NoSQL database©myNoSQL)

via: http://blog.mongodb.org/post/44706549534/mongodb-tip-the-touch-command

Francois Zaninotto:

MongoDB 2.1 introduced the aggregation framework, a faster alternative to Map/Reduce for common aggregation operations. If you took a look at the documentation and examples, you may have found the feature intimidating. Once you tame it, this new feature reveals itself as a very powerful beast. So read on to discover its true power through a series of examples.

The aggregation framework is indeed an interesting feature of MongoDB. And it’s definitely more useful compared to MongoDB’s MapReduce which came with quite a few limitations. Now MongoDB has 3 different languages: the object-based query language, the aggregation framework (still object-based but using different operators and execution model) and the Javascript-based MapReduce.

Original title and link: Comparing MongoDB New Aggregation Framework and SQL (NoSQL database©myNoSQL)

via: http://architects.dzone.com/articles/comparing-mongodb-new

Rackspace in a post explaining why they bought into MongoDB through the acquisition of ObjectRocket:

MongoDB is easy to get started, but complex to manage and scale.

I bet 10gen loves reading things like this. It also serves well the adoption of MongoDB.

Original title and link: MongoDB Represents the Perfect Opportunity for Rackspace’s Fanatical Support (NoSQL database©myNoSQL)

via: http://www.rackspace.com/blog/why-mongodb/

The Mortar blog:

Mongo was built for data storage and retrieval, and Hadoop was written for data processing. So naturally, data processing is often better offloaded to Hadoop. Here’s why:

1. Easier, more expressive language
2. Libraries to build on
3. Big performance improvements
4. Separate workloads mean less load

For the how part, the post recommends their own Hadoop-as-a-Service platform and a set of libraries the Mortar platform provides.

✚ While browsing the Mortar blog and website I couldn’t find any information related to the costs of transferring data. The AWS services usually have a data transfer dimension, which most often has an important impact on the total costs of a solution.

Original title and link: Integrating MongoDB and Hadoop: Why & How (NoSQL database©myNoSQL)

via: http://blog.mortardata.com/post/43080668046/mongodb-hadoop-why-how

In this post, we’ll see how to install MongoDB support for Pig and we’ll illustrate it with an example where we join 2 MongoDB collections with Pig and store the result in a new collection.

Color me very biased this time, but all these (especially the JOIN) can be done directly using RethinkDB.

Original title and link: Using Hadoop Pig With MongoDB (NoSQL database©myNoSQL)

via: http://chimpler.wordpress.com/2013/02/07/using-hadoop-pig-with-mongodb/