Manage Clusters

Required Access

To view your clusters, you must have Project Read Only access or higher to the project.

Procedure

atlas clusters list [options]

atlas clusters describe <clusterName> [options]

atlas clusters advancedSettings describe <clusterName> [options]

Free Clusters and Flex Clusters

Use Free clusters and Flex clusters as an economical way for getting started with MongoDB and for low-throughput applications. These clusters deploy to an environment with access to a subset of Atlas features. To learn more about Free cluster and Flex cluster limitations, see:

• Atlas Free Cluster Limits

• Atlas Flex Limitations

You can deploy one Free cluster (free sandbox replica set cluster) per Atlas project. You can scale a Free cluster to a Flex cluster or to a dedicated cluster at any time.

Flex clusters provide the following added features compared to Free clusters:

• Backups for your cluster data

• Increased storage

• API access

When you create a Free cluster or a Flex cluster, you can select Atlas Infinite or Atlas Core. The selection doesn't change your Free cluster or Flex cluster. Atlas stores the selection and applies it when you scale the cluster tier to a dedicated cluster, where you can optionally select a different edition. To learn more, see Scale a Free or Flex Cluster to a Dedicated Cluster.

Dedicated Clusters for Low-Traffic Applications

M10 and M20 cluster tiers support development environments and production environments with low-traffic applications.

These cluster tiers support replica set deployments only, but otherwise provide full access to Atlas features.

Dedicated Clusters for High-Traffic Applications

M30+ clusters are recommended for production environments.

These cluster tiers support replica set and sharded cluster deployments with full access to Atlas features.

Some clusters have variants, denoted by the ❯ character. When you select these clusters, Atlas lists the variants and tags each cluster to distinguish their key characteristics.

Gen2 Dedicated clusters

M30+ Atlas Core clusters are available in cluster generations Gen1 or Gen2 on AWS and Google Cloud. On Atlas Core clusters, Gen2 Dedicated clusters offer improved performance compared to Gen1 clusters and support Extended Standard IOPS, offering the following benefits:

• Optimized price performance.

• Newer hardware that enables long-term growth and avoids capacity restraints from older hardware.

• Independent scaling of your cluster's standard IOPS and storage capacity with increased maximum standard IOPS rates:

  • 80k IOPS for AWS

  • 160k IOPS for Google Cloud

M30+ Atlas Infinite clusters are available on Gen2 only, and don't support Extended Standard IOPS. To learn more about how Atlas Infinite clusters handle storage and IOPS, see Manage Storage on an Atlas Infinite Cluster and Atlas Infinite Storage IOPs and Throughput Values per Cluster Tier.

When creating a new cluster through the Atlas UI, Atlas automatically selects the Gen2 option under the Cluster Tier section for eligible clusters. For an Atlas Core cluster, you can select Gen1 instead to deploy a Gen1 cluster.

For existing clusters, you can switch between generations in the same way you would change your cluster's tier. To learn more, see Modify the Cluster Tier.

Sharded Clusters

A sharded cluster distributes your data across multiple shards, each a replica set, to horizontally scale your Atlas deployment and efficiently handle growing data and workloads. To learn how to configure and manage sharding, see Manage Cluster Sharding.

You can use the Atlas Administration API to choose a different tier per shard in a sharded cluster. You can also select Analytics node tiers independently for each shard. The largest and smallest shard tiers must be within two tiers of each other. For example, if the largest shard is M50, the smallest shard can be M30 or M40. If you change the cluster tier for a sharded cluster in the Atlas UI, Atlas changes the tier of all shards in the cluster.

You can also use the Atlas Administration API to choose different IOPS per shard if the cluster is on AWS using AWS provisioned IOPS or the cluster is on Azure in regions that support Extended IOPS/storage.

Atlas Infinite doesn't support sharded clusters in public preview. For the features supported in public preview, see Public Preview Availability.

To learn more, see Manage Cluster Sharding and the Update One Cluster in One Project endpoint in the Atlas Administration API documentation.

NVMe Storage

For applications hosted on AWS or Azure that require low-latency and high-throughput I/O, Atlas offers storage options using locally attached ephemeral NVMe SSDs.

Free, Flex, and Dedicated Cluster Comparison

The following table highlights key differences between Free clusters, Flex clusters, and Dedicated Atlas Core clusters.

For a complete list of Free cluster limitations, see Atlas Free Cluster Limits.

To learn more, see Auto-Scaling for Atlas Clusters.