Choose between periodic and continuous backup

When it comes to backing up your data in Microsoft Azure Cosmos DB, you have two options to choose from: periodic backup and continuous backup. Both methods have their advantages and considerations, so it’s important to understand the differences between them before deciding which one to implement in your native applications. In this article, we will explore both periodic and continuous backup in Azure Cosmos DB and help you make an informed decision.

Periodic Backup

Periodic backup, as the name suggests, involves taking snapshots of your data at regular intervals. Azure Cosmos DB offers automated periodic backups that can be scheduled up to once every four hours. These backups are stored in Azure Blob storage, providing an additional layer of protection for your data.

To configure periodic backups, you need to specify the frequency and retention period. Azure Cosmos DB takes care of the backup process, including choosing an appropriate point in time for each backup. This method allows you to restore your data to a specific point in time, giving you the ability to recover from accidental data corruption or deletion.

Continuous Backup

Continuous backup is a more granular and frequent backup option available in Azure Cosmos DB. With continuous backup, changes to your data are captured in real-time and stored in Azure Blob storage. This means that every write operation on your data will trigger a backup immediately, ensuring minimal data loss in case of any failure.

To enable continuous backup, you need to configure the Azure Cosmos DB container with the appropriate change feed policy. The change feed captures incremental changes and writes them to the backup storage account. This method provides a high level of data protection, as it ensures that every change made to your data is backed up without delay.

Considerations for Choosing Between Periodic and Continuous Backup

Both periodic and continuous backup methods offer different levels of protection and recovery options. The choice between them depends on your application requirements and considerations. Here are a few factors to consider when making a decision:

1. Recovery Point Objective (RPO): RPO refers to the acceptable amount of data loss during a recovery. If your application demands minimal data loss, continuous backup provides a close-to-real-time RPO. On the other hand, periodic backup has a higher RPO based on the backup interval.
2. Cost: Continuous backup comes with additional costs due to the frequent backups and storage requirements. Periodic backup, being less frequent, may incur lower costs. Consider your budget and the value of your data to determine the most cost-effective option.
3. Backup Frequency: Think about how frequently your data changes and the impact of potential data loss. If your data is constantly changing and any loss can have serious consequences, continuous backup is a better choice. For less dynamic data, periodic backup might suffice.
4. Regulatory Compliance: Certain industries and regions have specific compliance requirements that dictate how data backups should be implemented. Ensure that your chosen backup method aligns with any compliance regulations you need to adhere to.

Example of Configuring Periodic Backup

To configure periodic backup in Azure Cosmos DB, you can use the Azure portal or the Azure CLI. Here’s an example using the Azure CLI:

az cosmosdb sql container backup create \
--account-name \
--account-resource-group \
--database-name \
--container-name \
--backup-name \
--backup-storage-account-url \
--frequency \
--retention


Replace the placeholders with your Azure Cosmos DB account name, resource group name, database name, container name, backup name, blob storage account URL, backup frequency, and retention period.

Conclusion

Choosing between periodic and continuous backup in Azure Cosmos DB depends on your specific application requirements, recovery objectives, and cost considerations. Periodic backup provides scheduled snapshots with a longer recovery point, while continuous backup offers near real-time granularity but may incur additional costs. Consider the nature of your data, its importance, and compliance requirements to make an informed decision about which backup method suits your application best.