Convert a Shared Cluster to a Serverless Instance

Limitations

Serverless instances don't support the same features as shared clusters. If you change your shared cluster to a serverless instance, you lose access to the following features.

MongoDB plans to add support for more configurations and capabilities on serverless instances over time. To learn which features MongoDB plans to support for serverless instances in the future, see Serverless Instance Limits.

To see the full list of limitations for serverless instances, see Serverless Instance Limits. Atlas supports some features listed in the Serverless Instance Limits only for dedicated clusters, so the features might be unsupported for your current shared cluster tier.

Compatibility

• You can't convert a shared cluster to a serverless instance if you connected the cluster to any of the following:

  • Atlas App Services

  • Atlas Search

  You must disconnect the shared cluster from these features before you convert to a serverless instance.

  Note

  You can convert your shared cluster to a serverless instance 15-20 minutes after you disconnect it from Atlas App Services and Atlas Search.

• You can't convert a cluster that contains a capped collection to a serverless instance.

• You can't convert a cluster to a serverless instance if you use collation on the cluster's collections, indexes, or queries.

• You can't convert a paused M0 cluster to a serverless instance. You must resume the paused cluster before you change it to a serverless instance.

Operational Considerations

• Shared clusters always follow a major release cadence. Serverless instances always run on the latest MongoDB release, which may be a rapid release. Atlas automatically upgrades to the latest MongoDB version when you convert to a serverless instance, but you should:

  • Ensure that the latest MongoDB version is compatible with your application.

  • Consider that you can't reverse conversion to a serverless instance. To revert to using a cluster after you convert to a serverless instance, you must use mongodump and mongorestore to manually migrate your data to a new cluster.

    mongodump and mongorestore support migration only between database deployments of the same MongoDB version. As a result, if the MongoDB version of the serverless instance is later than all available major versions for shared clusters, you can migrate only to a dedicated cluster until the next major version release.

  To learn more about release cadences, see Choosing a Release Cadence.

• You can connect to a serverless instance only using a DNS seed list connection string. If you use a different connection string format to connect to your shared cluster, change your connection string after you convert to a serverless instance. To learn more and find your connection string, see Connect to Your Cloud Database Deployment.

• If you use MongoDB Charts, all existing charts that use this cluster won't render until you update the data source to the respective collection in the new serverless instance.

Downtime During Conversion

Your database deployment must go offline while it converts to a serverless instance. As a result:

• You can't read/write to the database deployment while Atlas converts a shared cluster to a serverless instance.

• Atlas doesn't preserve sessions, transactions, retryable writes, and change streams from before the conversion.

Billing Considerations

• Serverless instances offer pay-per-operation pricing. You pay only for the Processing Units consumed by your database operations and storage consumed by your data and indexes. To learn more, see Serverless Instance Costs.

• Atlas selects Serverless Continuous Backup by default when you convert a shared cluster to a serverless instance. To learn about the costs associated with continuous backup, see the Continuous Backup row of the Usage Cost Summary in Serverless Instance Costs.