When CosmosDB was Azure DocumentDB

About 3 years or so ago Microsoft Azure launched Azure DocumentDB (sounds familiar). In May of 2017 they rebranded it CosmosDB.


From this day forward, DocumentDB will no longer be called DocumentDB. Instead we will call this NoSQL, Document based database service…… Azure Cosmos DB.

A few months before the rebranding, MSFT announced this.


Today, we are excited to announce that DocumentDB: API for MongoDB is generally available. The API for MongoDB allows developers to experience the power of the DocumentDB database engine with the comfort of a managed service and the familiarity of the MongoDB SDKs and tools. With the announcement of its general availability, we are introducing a suite of new features for improvements in availability, scalability, and usability of the service.

Sound familiar?

A few years, NoSQL Document Storage, mostly ignored by the big database players, stormed onto the scene. I’d say thanks
mostly to Mongodb. From near obscurity (it has existed for years).

Azure wanted a piece so they came out with DocumentDB. It never really caught on even after the big rebrand and the addition of Mongo API feed.

In contrast what has MongoDB accomplished since that March 2017 launch by Azure DocumentDB? Admittingly, Amazon is the big Kahuna in Public Cloud, but Azure is a gaint force as well.

My belief, and is central to MDB thesis. NoSQL and specifically NoSQL Document Store is a tornado on a rampage that is fundamentally disrupting the database industry and is in the early innings. To this point that disruption has been utterly dominated by MongoDB. First Mover, Top Dog, and Category Crusher.

Azure created DocumentDB to Compete against MongoDB. When that failed they changed the name added some features and moved to support Mongo APIs. That has failed.

Amazon created DynamoDB to compete with MongoDB. When that failed they launched DocumentDB to support Mongo APIs. Success TBD.

The two biggest Cloud Titans have failed to produce a Mongo replacement in DocumentDB and in DynamoDB. They have accepted they can’t win so instead they are making a product that uses the APIs from the Top Dog. Making a product that can be Top Dog like, but will never be Mongo.

Cosmos will forever be Mongo 3.2 amd Document will be forever 3.6.

Both will impact Mongo’s sales. But the market that Mongo is in is on fire. They still have a long long way before they show signs of not finding new customers or selling more to existing customers.



Here Mongo has a comparison chart of features Of Atlas vs Mongo “Imitators” (for lack of a better descriptor) like CosmosDB.

Amazon DocumentDB doesn’t have a column yet, but from what I’ve read it’s probably fairly close to Cosmos except change 3.2 to 3.6.