Introduction to Azure Cosmos DB

Welcome to the introduction to Azure Cosmos DB. This tutorial will guide you through the fundamental concepts and benefits of Azure Cosmos DB, Microsoft's globally distributed, multi-model database service.

What is Azure Cosmos DB?

Azure Cosmos DB is a fast, scalable, and highly available NoSQL database service. It's designed for modern application development and offers a variety of data models and APIs to support diverse use cases.

Key Features:

Global Distribution: Distribute your data across any number of Azure regions worldwide with just a few clicks.
Multi-Model: Supports data in document, key-value, graph, and column-family formats.
Multiple APIs: Interact with your data using familiar APIs like SQL (Core), MongoDB, Cassandra, Gremlin, and Table.
Guaranteed Throughput and Latency: Offers predictable performance with low latency and high throughput, backed by comprehensive SLAs.
Elastic Scalability: Scale throughput and storage up or down on demand without downtime.
Tunable Consistency: Provides five well-defined consistency levels to balance availability and performance.

Why Use Azure Cosmos DB?

Azure Cosmos DB is an excellent choice for applications that require:

Massive Scale: Handle petabytes of data and millions of requests per second.
High Availability: Ensure your application is always accessible with built-in fault tolerance and automatic failover.
Low Latency: Deliver responsive user experiences by serving data from a region close to your users.
Diverse Data Needs: Support various data structures and access patterns within a single database service.

Important: Azure Cosmos DB is designed for mission-critical applications where performance, availability, and scalability are paramount.

Core Concepts

Understanding these core concepts will help you leverage Azure Cosmos DB effectively:

Account: The top-level resource in Azure Cosmos DB.
Database: A container for collections or tables.
Container: A logical grouping of items (documents, rows, nodes, edges). In SQL API, this is a collection; in Cassandra API, a table.
Item: The basic unit of data stored in a container (e.g., a JSON document in SQL API).
Partition Key: A property within an item that Azure Cosmos DB uses to distribute data and throughput across logical partitions.
Request Units (RUs): A normalized measure of throughput that abstracts the underlying system resources (CPU, memory, IOPS, etc.).

Tip: Choosing an effective partition key is crucial for performance and scalability. Aim for a partition key with high cardinality.

Getting Started

To start using Azure Cosmos DB, you'll need:

An Azure subscription.
To create an Azure Cosmos DB account in the Azure portal.
To choose your API and create a database and container.

Example: Creating an item (SQL API)


{
    "id": "todo1",
    "category": "personal",
    "name": "Groceries",
    "description": "Buy milk and eggs",
    "isComplete": false
}

This introduction provides a foundational understanding of Azure Cosmos DB. In subsequent tutorials, we will delve deeper into specific APIs, data modeling strategies, and best practices for building robust applications.

Continue to the next tutorial to learn how to set up your development environment and create your first Azure Cosmos DB database.