A Flex cluster is a shared MongoDB Atlas tier for small applications, development, and testing. Its base monthly plan includes 5 GB of storage, 100 operations per second, and unlimited data transfer. Capacity scales with use, but additional operations may incur charges. section 10.1
Choose Flex when the free M0 tier is too limited but a dedicated cluster is unnecessary. Flex runs as a replica set on shared hardware, which reduces cost but limits performance and available features. It is not recommended for production workloads or sensitive data. section 10.1
Plan around these operational limits:
- To move from M0 to Flex, select Edit Configuration in the Atlas UI and choose Flex under Cluster Tier. Changing tiers among M0, Flex, and M10 requires 7–10 minutes of downtime. section 10.1
- Flex storage size and memory cannot be configured. Its three-node replica set cannot be changed to a sharded cluster. section 10.1
- Atlas starts taking daily snapshots 24 hours after cluster creation and retains the eight most recent. Flex has no on-demand snapshots or point-in-time restore. section 21.1.1
Restore a Flex snapshot
In the Atlas UI, open Clusters, select the project, and open the cluster’s Backup tab. Choose a snapshot, select Restore from its Actions menu, choose a target cluster, and confirm. Restart the application to connect to the updated cluster. Flex restoration is not supported in the Atlas CLI, and snapshots can be restored only to replica sets. section 21.1.2
