Implement data archiving by using a change feed

Data archiving is an essential process for managing large amounts of data in applications. It ensures data integrity, regulatory compliance, and improves performance by removing outdated or infrequently accessed data from active databases. This article will guide you through the implementation of data archiving using the change feed feature in Microsoft Azure Cosmos DB.

Step 1: Create an Azure Cosmos DB Account

To begin, create an Azure Cosmos DB account by following these steps:

1. If you don’t have an Azure subscription, sign up for a free account.
2. Refer to the documentation on how to create an Azure Cosmos DB account to create your account.

Step 2: Choose an API and Configure Data Model

Next, select the appropriate API based on your data model requirements. Azure Cosmos DB supports various NoSQL data models, including key-value, document, graph, and columnar. Set up your containers or collections accordingly and ensure that the containers have a TTL (Time to Live) property defined.

Step 3: Enable the Change Feed Feature

Follow these instructions to enable the change feed feature in your Azure Cosmos DB account:

1. Open your Azure Cosmos DB account in the Azure portal.
2. In the left-hand menu, navigate to “Data Explorer” and click on “Change Feed.”
3. Enable the change feed by toggling the button.

Step 4: Implement Archiving Logic

Now it’s time to implement your archiving logic using Azure Functions and the change feed feature. Here’s an example implementation in C#:

using Microsoft.Azure.Documents;
using Microsoft.Azure.Documents.ChangeFeedProcessor;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.Extensions.Logging;

private static bool IsArchivable(Document document)
{
// Implement your archiving criteria logic here
// For example, check if the document is older than a specific date
var createdDate = document.GetPropertyValue("createdDate");
var retentionDate = DateTime.UtcNow.AddYears(-1);
return createdDate < retentionDate; } }

In this example, an Azure Function is created to process the change feed events triggered by the Cosmos DB container. The function checks the archiving criteria for each document and moves the qualifying documents to an archival storage, such as Azure Blob Storage.

Make sure to configure the necessary connection strings and access rights for your Azure Functions app, Azure Cosmos DB, and archival storage account.

By utilizing the change feed feature in Azure Cosmos DB, you can easily implement an efficient and scalable data archiving solution. The change feed provides a reliable stream of data changes, enabling seamless integration with other Azure services and custom logic for archiving.