Specify application connections to replicated data

Azure Cosmos DB is a globally distributed, highly scalable, and multi-model database service offered by Microsoft. When designing and implementing native applications using Azure Cosmos DB, it is important to understand how to specify application connections to replicated data. This article will guide you through the process of establishing connections to replicate data for your applications, using Azure Cosmos DB.

Consistency Models in Azure Cosmos DB

Azure Cosmos DB offers multiple consistency models, which govern the behavior of reads and writes across replicated data. The consistency models include:

• Strong: Provides immediate consistency, ensuring that the latest write is always returned to the client.
• Bounded staleness: Offers a configurable lag between reads and writes, providing a balance between consistency and performance.
• Session: Guarantees strong consistency within a session, maintaining the order of operations for a specific client.
• Consistent prefix: Ensures that clients never see out-of-order writes, providing a consistent prefix of the data across all reads.
• Eventual consistency: Allows for the maximum possible read throughput, offering eventual consistency across all replicas.

Each consistency model provides a different level of trade-off between performance, availability, and data consistency.

Specifying the Application Connection

To specify the application connection to replicated data, you need to include endpoint and key information in your application code. This information can be obtained from the Azure portal or programmatically using Azure SDKs. Here’s an example of how to specify the connection information in a C# application:


using Microsoft.Azure.Documents.Client;

In the above code snippet, replace “your-cosmosdb-endpoint-url” with the actual URL of your Azure Cosmos DB endpoint, and “your-cosmosdb-authorization-key” with the authorization key associated with your Azure Cosmos DB account. The DocumentClient class is provided by the Azure Cosmos DB .NET SDK and allows you to interact with your Azure Cosmos DB account programmatically.

Working with Replicated Data

Once you have established the connection to the Azure Cosmos DB account, you can start working with your replicated data. This includes performing operations such as reading, writing, updating, and deleting documents. Here’s an example of how to create a new document in a collection:


// Specify the database and collection names
string databaseName = "your-database-name";
string collectionName = "your-collection-name";

// Create the document in the specified collection
await client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(databaseName, collectionName), document);


In the above code snippet, replace “your-database-name” with the actual name of your Azure Cosmos DB database and “your-collection-name” with the name of the collection where you want to create the document. The CreateDocumentAsync method is provided by the DocumentClient class and allows you to create a new document asynchronously.

Remember to handle any exceptions that may occur during the connection establishment or data operations. Wrap your code within try-catch blocks and implement appropriate exception handling logic.

Conclusion

Specifying application connections to replicated data in Azure Cosmos DB involves including the endpoint and key information in your application code. You can then use this connection to interact with your replicated data by performing various operations. The examples provided in this article demonstrate how to establish a connection and create a new document in Azure Cosmos DB.