Choose when to use multi-region write

When working with Microsoft Azure Cosmos DB, you have the flexibility to choose when to use multi-region write capabilities. Multi-region write allows you to write data to multiple regions simultaneously, ensuring high availability and low latency for your applications. In this article, we will explore different scenarios where you might consider utilizing multi-region write in your native applications.

1. Disaster Recovery:

In the event of a region-wide failure, multi-region write can help you maintain business continuity. By replicating your writes across multiple regions, you can ensure that your data is safe even if one region becomes unavailable. You can use Azure Cosmos DB’s automatic failover feature to switch to a healthy region seamlessly and continue serving your application.

// Enable multi-region write for Cosmos DB account
PUT https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.DocumentDB/databaseAccounts/{accountName}?api-version=2021-03-15
{
"properties": {
"enableMultipleWriteLocations": true
}
}

2. Geolocation Considerations:

If your application has a global user base, using multi-region write can help minimize latency by allowing users to write data to the region closest to them. This ensures that data traverses a shorter distance, resulting in faster response times. Additionally, Azure Cosmos DB automatically routes read requests to the closest available region, further improving performance.

// Select preferred write region
POST https://.documents.azure.com/dbs//colls/?api-version=2021-03-15
x-ms-cosmos-preferred-locations: West US, East US


3. Meet Compliance Requirements:

Some industries have strict compliance requirements regarding data residency. Multi-region write allows you to store data in specific regions to meet these compliance requirements. Azure Cosmos DB enables you to choose the regions where data will be stored and ensures that data is written to and remains within those regions.

// Specify preferred write region during document creation
POST https://.documents.azure.com/dbs//colls//docs?api-version=2021-03-15
x-ms-cosmos-preferred-regions: West US, East US


4. Bursting Write Workloads:

Multi-region write can handle bursty write workloads by distributing write operations across multiple regions. This helps to prevent write throttling and ensures that your application can handle sudden spikes in traffic. Azure Cosmos DB automatically load balances writes across regions, providing high throughput for write-intensive applications.

// Write to multiple regions in parallel
POST https://.documents.azure.com/dbs//colls//docs?api-version=2021-03-15
x-ms-cosmos-databaseaccount-write-global-flag: true


By leveraging Azure Cosmos DB’s multi-region write capabilities, you can design and implement native applications that are highly available, scalable, and performant. Whether you need disaster recovery, better geolocation support, compliance adherence, or the ability to handle bursty workloads, multi-region write empowers you to meet these requirements. Experiment with the provided code snippets and determine the best approach for your application’s needs.