A typical scale-out architecture might look like this:
Each process in the NuoDB architecture represents a virtual or physical cloud resource but the database as a whole continues to represent itself as a single logical database to any client that’s connected to it.
Many of you have been developing, deploying and maintaining .NET applications using SQL Server and might be familiar with setting up a server farm or application cluster to improve performance. As you know, this is no easy task, from both a development and deployment perspective. I’m not advocating that you eliminate SQL Server from your stack, but let’s entertain the idea of using NuoDB as the primary database for your application backend. Since it presents itself as a single logical database to your application regardless of how many machines it might be running on, you’re able to simplify your code and your scale-out strategy. The transaction engine layer of NuoDB uses a dynamic caching mechanism to eliminate the need to shard or federate your data. Transaction engines connect directly to client applications and are able to process all transaction types (CRUD) and maintain data consistency across the entire deployment environment. This opens up the opportunity to write applications specifically designed for a scale-up architecture and leverage NuoDB to provide scale-out capabilities. Below is an example of co-locating transaction engines on each node in a server farm.
The genius of this system is that co-located transaction engines should be the most responsive to the application. However, in the event that one or more transaction engines get tied up, the broker process automatically connects applications to the next most responsive. There is no prerequisite for the data to actually be present on the transaction engine. NuoDB uses a built-in asynchronous replication technique to get data directly from other transaction engines or storage managers.