Skip to main content

Description

Ensure that Azure Cosmos DB accounts with analytical storage enabled use continuous backup instead of periodic backup. This configuration aligns the backup mode with analytical workloads and helps identify opportunities to reduce avoidable costs.

Rationale​

Analytical storage supports large-scale analytical workloads, including Synapse Link and Fabric Mirroring scenarios. Continuous backup is the recommended backup mode for eligible workloads and can be more cost-effective than periodic backup. It also supports point-in-time restoration within the configured retention period.

Impact​

Using periodic backup for an eligible analytical workload can result in avoidable backup costs and provides restoration only from scheduled backup copies. Changing from periodic to continuous backup is a one-way operation that can affect backup retention options, restore procedures, regional availability, and cost. Plan the change around the workload's operational and recovery requirements.

Audit​

This policy flags an Azure Cosmos DB Account as INCOMPLIANT when both of the following conditions are true:

  • Analytical Storage is set to Enabled.
  • Backup Policy Type is set to Periodic.

An account is COMPLIANT when analytical storage is enabled and the backup policy type is Continuous. An account is INAPPLICABLE when analytical storage is disabled. The result is UNDETERMINED when either setting is unavailable or has an unrecognized value.

References​

  1. https://learn.microsoft.com/en-us/azure/cosmos-db/continuous-backup-restore-introduction
  2. https://learn.microsoft.com/en-us/cli/azure/cosmosdb#az-cosmosdb-show