Last week at Microsoft Build, a new type of database was announced: Cosmos DB.
It sounds cool, but what is it?

Basically, Cosmos DB is an abstraction level over datastores like Azure DocumentDB, and Table Storage.

Cosmos DB abstracts those datastores for you and thereby provides you with some great benefits, like:

  • Guaranteed global low latency for reads (10ms) and writes (15ms)
  • SLA for availability 99.99%
  • Global distribution of your data
  • Flexible scaling models
  • Whatever Microsoft will add in the future...

The major benefit is that Cosmos DB provides low latency reads AND writes. Even when they still implement a single write node and multiple read nodes in their geo-replication feature. In this article, they explain how they achieve this low latency. This is great news for global applications as they can now more easily enjoy global performance and high availability.

If you are a DocumentDB customer

You no longer are. You are now a Cosmos DB customer using the DocumentDB API. Nothing changes for you, you only gain potential benefits.

The future

I expect that more data stores will be put under the Cosmos DB umbrella and therefore will benefit from the benefits that it offers. I'm keen to see what features Microsoft will add to Cosmos DB to make it even more attractive. Great move Microsoft!