Azure Cosmos DB

What is Azure Cosmos DB?

Azure Cosmos DB is a fully managed, globally distributed, multi-model NoSQL database service by Microsoft Azure. It is designed for mission-critical applications that require low latency, high availability, and global scalability.

Offers multi-region replication with high availability SLA (99.999%)
Supports multiple APIs: SQL (Core), MongoDB, Cassandra, Gremlin, Table
Automatically scales throughput and storage based on workload
Provides low-latency reads and writes globally
Offers multi-model support (document, key-value, graph, column-family)

What is Azure DocumentDB?

Azure DocumentDB was the original NoSQL document database from Microsoft, focused on JSON data and SQL-like querying. It has been fully integrated and evolved into Azure Cosmos DB, making Cosmos DB the successor with extended capabilities.

Built for fast and predictable performance
Supports elastic scaling and global distribution
Now part of the broader Cosmos DB platform

Azure Cosmos DB vs. Hadoop

While both Cosmos DB and Hadoop work with large-scale data, they serve different purposes and architectures.

Feature	Azure Cosmos DB	Hadoop
Type	Managed NoSQL database (DBaaS)	Distributed data processing framework
Primary Use	Operational, real-time data access	Batch processing and analytics
Data Model	Document, key-value, graph, column-family	HDFS (file-based), any format via tools
Scalability	Global, auto-scale on demand	Horizontal scaling via manual node setup
Latency	Low-latency reads/writes (millisecond range)	High-latency batch jobs (minutes or hours)
Use Case	Real-time apps, IoT, retail, gaming	Big data ETL, analytics, machine learning

When to Use Azure Cosmos DB

When you need globally available, low-latency access to data
For applications requiring real-time analytics
To support NoSQL data models with high throughput
When you want a serverless, managed database service