Azure Cosmos DB Blog
The latest news, updates and technical insights from the Azure Cosmos DB team
Latest posts
Part 1: Building Your First Serverless HTTP API on Azure with Azure Functions & FastAPI
Introduction This post is Part 1 of the series Serverless Application Development with Azure Functions and Azure Cosmos DB, where we explore how to build end-to-end serverless applications using Azure Functions for compute and Azure Cosmos DB for storage. Together, these services allow you to build scalable, event-driven, cost-efficient cloud solutions without managing servers or infrastructure. Throughout the series, you’ll progressively build real application components starting with simple HTTP APIs, adding persistent storage, implementing event-driven patterns using the Cosmos DB Change Feed, and orches...
Azure Cosmos DB Conf 2026 — Call for Proposals Is Now Open
Every production system has a story behind it. The scaling limit you didn’t expect. The data model that finally clicked. The tradeoff you had to make under real-world pressure. The solution that worked—and the lessons you’d pass on to the next team. Azure Cosmos DB Conf 2026 is where those stories get shared. This is a global, developer-first conference focused on real-world engineering with Azure Cosmos DB, Azure DocumentDB, and open-source DocumentDB. It’s about showing how things actually work in production—through real architecture, real code, and live demos—not high-level concepts or marketing ...
Powering Real-Time Gaming Experiences with Azure Cosmos DB for NoSQL
Scenario: When Every Millisecond Counts in Gaming Imagine millions of players logging in at the exact moment a new game season launches. Leaderboards light up, achievements tally, and in-game shops buzz with transactions. In these high-stakes moments, speed and reliability aren’t optional, they’re mission critical. That’s where Azure Cosmos DB with the NoSQL API steps in, powering real-time, global gaming experiences without missing a beat. Why Gaming Needs a Next-Gen Database Modern gaming experiences must withstand massive user surges, where game launches and updates can trigger huge spikes in concurrent p...
Public Preview: Cosmos DB Mirroring in Microsoft Fabric with Private Endpoints
We are very excited to announce the public preview for private endpoint support for Azure Cosmos DB Mirroring with Microsoft Fabric mirroring. This feature allows you to preserve the enhanced network security on your data in Cosmos DB from virtual networks or private endpoints, allowing you to seamlessly replicate your operational data in Cosmos DB using Mirroring into your Fabric Workspaces. Configuring Mirroring with Private Endpoints The process for configuring Mirroring on your Cosmos DB accounts with private endpoints during our preview requires multiple steps. To see these steps in detail...
Build AI Tooling in Go with the MCP SDK – Connecting AI Apps to Databases
A hands‑on walkthrough of building MCP servers that can plug AI applications into Azure Cosmos DB The Model Context Protocol (MCP) has established itself as the ubiquitous standard for connecting AI applications to external systems. Since its release, there have been implementations across various programming languages and frameworks, enabling developers to build solutions that expose data sources, tools, and workflows to AI applications. For Go developers, however, the journey to an official MCP SDK took longer (compared to other SDKs like Python and TypeScript). Discussions and design/implementation w...
How Azure Cosmos DB Powers ARM’s Federated Future: Scaling for the Next Billion Requests
The Cloud at Hyperscale: ARM’s Mission and Growth Azure Resource Manager (ARM) is the backbone of Azure’s resource provisioning and management, orchestrating billions of daily requests from customers around the globe. ARM manages all resources for Azure: VMs, Storage, Databases, etc. As Azure’s reach expands and customer expectations rise, ARM’s architecture must not only keep pace—it must set the pace for cloud-scale reliability, agility, and innovation. In recent years, ARM has seen its request volume surge at an exponential rate, reaching unprecedented levels that continually redefine the boundaries of c...
Unlock the power of distributed graph databases with JanusGraph and Azure Apache Cassandra
Connecting the Dots: How Graph Databases Drive Innovation In today’s data-rich world, organizations face challenges that go beyond simple tables and rows. Whether it’s uncovering hidden relationships in social networks, detecting fraud, or powering recommendation engines, graph databases offer a unique way to model and analyze complex connections. JanusGraph, an open-source graph database, combined with Azure Managed Instance for Apache Cassandra, provides a scalable, secure, and flexible foundation for building graph-powered applications making it easier for teams to tackle problems that traditional database...
Azure Cosmos DB vNext Emulator: Query and Observability Enhancements
The Azure Cosmos DB Linux-based vNext emulator (preview) is a local version of the Azure Cosmos DB service that runs as a Docker container on Linux, macOS, and Windows. It provides a cost-effective way to develop and test applications locally without requiring an Azure subscription or network connectivity. The latest release brings improvements in two key areas: Query Improvements This emulator release enables several query patterns that were previously unsupported. In this post, we'll focus on the following enhancements to query capabilities: Let's explore these with practical...
Azure Cosmos DB : Becoming a Search-Native Database
For years, “Database” and “Search systems" (think Elastic Search) lived in separate worlds. While both Databases and Search Systems operate in the same domain (storing, indexing and querying data), they prioritized different aspects. OLTP Databases prioritized Search Systems prioritized AI and Agents are accelerating the dissolution of the boundary between these two systems. AI solves real world problems in near-real-time that needs both of these systems. Using separate systems for these specializations not only leads to high overhead, but leads to sub-optimal relevanc...
Long-term data retention up to 10 years: Announcing Private Preview of Azure Backup for Azure Cosmos DB
![Hans Wieser [MS]](https://devblogs.microsoft.com/cosmosdb/wp-content/uploads/sites/52/2025/12/Hans_Wieser_173-small-96x96.png){kind=avatar}
Azure Backup for Azure Cosmos DB is a new option that lets you securely protect and recover your Azure Cosmos DB data for compliance, audit, and ransomware protection scenarios. It leverages Azure Backup’s vault isolation and Azure Cosmos DB’s native backup streams to deliver scalable, long-term data protection that meets regulatory requirements. How does it work? During the private preview, you can configure backup schedules and retention policies at the Azure Cosmos DB account or collection level, stream backups to a vaulted, isolated Azure Backup Vault, and restore data to an empty Azure Cosmos DB account in...
Tata Neu delivers personalized shopping experiences for millions of users with Azure DocumentDB
With Azure DocumentDB, Tata Neu delivers seamless authentication for millions of users, accelerates credit card onboarding across partners, unifies loyalty programs for hundreds of millions of members, and powers AI-driven support experiences across more than 60 brands. This article is coauthored by Anurag Mathur, the VP and Head of Foundational Services at Tata Digital, and Bhaskar Chellappa, the VP and Head of TechOps at Tata Digital Introducing Tata Neu: Tata Digital's unified app Tata Neu is designed to deliver an extensive yet highly personalized shopping experience. The culmination of more than t...
Announcing: Dynamic Data Masking for Azure Cosmos DB (Preview)
Today marks a big step forward with the public preview of Dynamic Data Masking (DDM) for Azure Cosmos DB. This feature helps organizations protect sensitive data without requiring changes to application logic or database interactions. What is Dynamic Data Masking? Dynamic Data Masking (DDM) is a server-side, policy-driven security feature that automatically masks sensitive information for non-privileged users. When enabled, DDM ensures that only authorized users can view unmasked data, while others see masked or redacted values. The original data remains unchanged in the database, and masking occurs in real tim...
Use Azure SRE Agent with Azure Cosmos DB: Smarter Diagnostics for Your Applications
We’re excited to announce the Azure Cosmos DB SRE Agent built on Azure SRE Agent; a new capability designed to simplify troubleshooting and improve reliability for your applications running on Azure Cosmos DB. Some key features of Azure Cosmos DB SRE Agent are: Benefits of using Azure Cosmos DB SRE Agent Managing distributed applications can be complex. The Azure Cosmos DB SRE Agent bridges the gap by: Azure Cosmos DB SRE Agent Scenario Integrating Azure SRE Agent with your Azure Cosmos DB resource can leverage diagnostics to help identify issues or areas for improvement....
Announcing Private Preview: Safe Account Key rotation using Account Key Usage Metadata
Account Key Usage Metadata is a new security and observability feature that helps Azure Cosmos DB customers avoid service disruptions during key rotations. It provides visibility when each account key was last used, allowing teams to make informed decisions before rotating or migrating to Entra ID. This feature addresses a common challenge of rotating a key that appears unused but is still actively relied upon by critical applications—leading to unexpected outages. How Does It Work? In the private preview, on your Azure Cosmos DB account, you can view the last usage timestamp for each key. This timestamp r...
General Availability: Priority-Based Execution in Azure Cosmos DB
Have you ever faced a situation where two different workloads share the same container, and one ends up slowing down the other? This is a common challenge for many of our customers running applications on Azure Cosmos DB. Imagine these scenarios: In all these cases, there’s one workload you’d prefer to prioritize, ensuring critical operations run smoothly while others can progress slowly during resource contention. Introducing Priority-Based Execution Priority-Based Execution solves this problem. It lets you assign high priority to critical workloads and low priority to less important ones using...
Announcing Preview of Online Copy Jobs in Azure Cosmos DB: Migrate Data with Minimal Downtime!
We are excited to announce the preview of Online Copy Jobs, a powerful new feature designed to make data migration between containers seamless and efficient with minimal downtime. With this feature, you can replicate data from a source to a destination container in real time without disrupting your applications. What is an online copy job? Online Copy Jobs allow you to copy data from a source container to a destination container while your applications continue to run on the source. All data including incremental updates is automatically replicated, ensuring the destination container becomes an up-to-date repli...
Announced at Ignite 2025: Azure DocumentDB, MCP Toolkit, Fleet Analytics, and more!
Microsoft Ignite 2025 kicked off with a wave of announcements for Azure Cosmos DB and Azure DocumentDB, setting the tone for a week of innovation in cloud databases and AI. Here’s your one-stop summary of everything unveiled—and what to watch for in the sessions ahead. Major Azure Cosmos DB announcements from Ignite 2025 Azure DocumentDB now Generally Available Azure DocumentDB is now generally available, bringing a new level of openness, flexibility, and cost efficiency to MongoDB workloads. Built on the open-source DocumentDB engine – now governed by the Linux Foundation – Azure DocumentDB delivers Mongo...
Introducing Index Advisor for Azure DocumentDB (Preview)
We’re excited to announce the public preview of Index Advisor for Azure DocumentDB (with MongoDB Compatibility). It is a built-in AI powered performance tuning assistant that helps you understand slow queries, diagnose inefficiencies, and automatically generate optimized index recommendations. With Index Advisor, you can quickly analyze query structure, execution plans, and collection statistics to receive data-driven, plain-English index recommendations. Even better, you can apply these recommendations directly inside the DocumentDB for VS Code extension, making performance tuning faster, easier, and seamles...