Book Image

Guide to NoSQL with Azure Cosmos DB

By : Gaston C. Hillar, Daron Yöndem
Book Image

Guide to NoSQL with Azure Cosmos DB

By: Gaston C. Hillar, Daron Yöndem

Overview of this book

Cosmos DB is a NoSQL database service included in Azure that is continuously adding new features and has quickly become one of the most innovative services found in Azure, targeting mission-critical applications at a global scale. This book starts off by showing you the main features of Cosmos DB, their supported NoSQL data models and the foundations of its scalable and distributed architecture. You will learn to work with the latest available tools that simplify your tasks with Cosmos DB and reduce development costs, such as the Data Explorer in the Azure portal, Microsoft Azure Storage Explorer, and the Cosmos DB Emulator. Next, move on to working with databases and document collections. We will use the tools to run schema agnostic queries against collections with the Cosmos DB SQL dialect and understand their results. Then, we will create a first version of an application that uses the latest .NET Core SDK to interact with Cosmos DB. Next, we will create a second version of the application that will take advantage of important features that the combination of C# and the .NET Core SDK provides, such as POCOs and LINQ queries. By the end of the book, you will be able to build an application that works with a Cosmos DB NoSQL document database with C#, the .NET Core SDK, LINQ, and JSON.
Table of Contents (13 chapters)
Title Page
Packt Upsell

Learning about the resource hierarchy for each container

The following diagram shows the resource hierarchy for each container. For example, as previously learned, in a document database, the container is a collection:


The containers are the logical resources that are exposed to the APIs as collections, graphs, or tables. Each container has partition sets, which are composed of database replicas. The database service hosts four replicas per region. This way, whenever there are either hardware or software updates, they are completely transparent to us and we can continue working with the remaining replicas.

Resource partitions provide resource-governed coordination primitives. The following diagram shows a replica set in detail. Notice that each replica set hosts an instance of the database engine:


The database service is always online and available. The software and hardware updates on the Azure side happen under the hood for one out of four replicas per region while the remaining replicas continue working. Hence, we don't have to worry about availability due to operating system or database engine updates.