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Atlas M0 (Free Tier), M2, and M5 Limitations

The following table lists the configuration limitations of Atlas M0 Free Tier and M2/M5 shared clusters:

Configuration Option
Limitation
Cloud Service Provider and Region

M0 Free Tier clusters and M2/M5 shared clusters are only deployable in a subset of regions on AWS, GCP, and Azure. For more information on which cloud provider regions support free and shared tiers, see:

MongoDB Version and Storage Engine
Atlas uses MongoDB 4.4 for M0/M2/M5 clusters.
MongoDB Version Upgrade

You can't upgrade the MongoDB version that M0/M2/M5 clusters run.

Atlas upgrades M0/M2/M5 clusters to the newest MongoDB version after several patch versions become available for that version. To learn more about how MongoDB versions its software, see MongoDB Versioning.

Cluster Tier
You must select the M0 cluster tier to deploy a Free Tier cluster.
Cluster Memory
You cannot configure memory for M0 Free Tier or M2/M5 shared clusters.
Cluster Storage
You cannot configure storage size for M0 Free Tier or M2/M5 shared clusters.
Replication Factor
Replication Factor is set to 3 Nodes and cannot be modified for M0 Free Tier, or M2/M5 shared clusters.
Replica Set Tags
M0 Free Tier, and M2/M5 shared clusters are not configured with pre-defined replica set tags.
Do You Want A Sharded Cluster
You cannot deploy a M0 Free Tier or M2/M5 shared cluster as a Sharded Cluster.
Do You Want To Enable Backup

You cannot enable backups on M0 Free Tier clusters.

Tip
See also:

Backup Alternative: mongodump

You may use mongodump to back up your data and mongorestore to restore that data. To learn how to manually back up your data, see Command Line Tools.

Test Failovers
You cannot perform primary failover testing on M0 Free Tier or M2/M5 shared clusters.
Database Auditing
You cannot configure database auditing on M0 Free Tier or M2/M5 shared clusters.
Encryption at Rest using your Key Management
You cannot configure Encryption at Rest using Customer Key Management on M0 Free Tier or M2/M5 shared clusters.
Network Peering Connections
You cannot configure Set up a Network Peering Connection on M0 Free Tier or M2/M5 shared clusters.
Access Tracking
You cannot view the database access history for M0 Free Tier, or M2/M5 shared clusters.
Configure TLS Certificate Root
You cannot modify the Certificate Authority that MongoDB Atlas clusters use through the API for M0 Free Tier and M2/M5 shared clusters.

The following table lists the operational limitations of Atlas M0 Free Tier and M2/M5 shared clusters:

Operation
Limitation

Atlas Free Tier and shared clusters do not support the allowDiskUse option for the aggregation command or its helper method.

On Free Tier and shared clusters, aggregation fields that represent database and collection names (such as $merge into and $out values) cannot accept expressions as values.

On Free Tier and shared clusters, aggregation pipelines are restricted to 50 stages.

API Access
You cannot modify or configure an M0 Free Tier cluster using the Clusters API endpoint. A subset of API endpoints support M2 and M5 shared clusters.
Atlas Alerts

M0/M2/M5 clusters can only trigger alerts configured with one of the following alert conditions:

  • Connections
  • Logical Size
  • Network
  • Opscounter
Atlas Monitoring

The Metrics view of an M0 Free Tier or M2/M5 shared cluster only displays the following metrics:

  • Connections
  • Logical Size
  • Network
  • Opscounter

For more information on these metrics, see Real Time Metrics.

Authentication

M0 Free Tier and M2/M5 shared clusters support only the following authentication methods:

  • Password (SCRAM-SHA1)
  • X.509 Certificates
  • AWS IAM
Auto-Expand Storage
M0 Free Tier and M2/M5 shared clusters do not provide automatically scaling storage.
Build Index with Rolling Build
M0 Free Tier and M2/M5 shared clusters do not provide the ability to build indexes with a rolling build.
Cluster Persistence
Atlas may deactivate idle M0 Free Tier clusters as per the Terms of Service.
Connections
M0 Free Tier and M2/M5 shared clusters are allowed a maximum of 500 connections.
Cursors
Free tier and shared clusters cannot use the noTimeout cursor option.
Custom Roles
Changes to custom roles make take up to 30 seconds to deploy in M0 Free Tier and M2/M5 shared clusters.
Database and Collections
M0 Free Tier and M2/M5 shared clusters have a maximum of 100 databases and 500 collections total.
Database Commands

Certain database commands are unsupported or behave differently in an M0 Free Tier cluster. To learn more, see Command Limitations in Free Tier Clusters.

Please contact Atlas support for any questions or comments related to restricted commands.

Database Logs
M0 Free Tier and M2/M5 shared clusters do not provide downloadable logs.
Data Recovery
  • Custom policies are not supported for M2 and M5 cluster snapshots. Atlas always takes a single daily snapshot at the same time, starting 24 hours after the cluster was created.

    If you require finer-grained backups, consider upgrading to an M10 or larger cluster tier.

  • On-demand snapshots are not supported for M2 and M5 clusters.
  • You can't restore M2 and M5 snapshots to a sharded cluster. You can only restore M2 and M5 snapshots to replica sets.
Data Transfer Limits

M0/M2/M5 clusters limit the total data transferred into or out of the cluster in a rolling seven-day period. This varies by cluster tier as follows:

  • M0: 10 GB in and 10 GB out per period
  • M2: 20 GB in and 20 GB out per period
  • M5: 50 GB in and 50 GB out per period

Atlas throttles the network speed of clusters which exceed the posted limits.

JavaScript

M0 Free Tier and M2/M5 shared clusters do not support server-side JavaScript.

Example

$where and map-reduce are not supported.

Namespaces and Database Names
M0 Free Tier and M2/M5 shared cluster namespaces are limited to 95 bytes. Database names are limited to 38 bytes.
Number of Free Tier clusters
You can deploy at most one M0 Free Tier cluster per Atlas project.
Performance Advisor
M0 Free Tier and M2/M5 shared clusters do not provide access to the Performance Advisor.
Query Utilization
The percentage of time that a query is running over any five minute period must remain under 100% on M0 Free Tier and M2/M5 shared clusters.
Real-Time Performance Panel
M0 Free Tier and M2/M5 shared clusters do not provide access to the Real-Time Performance Panel.
Sort in Memory
M0/M2/M5 sort in memory limit is 32 MB.
Throughput

Maximum operations:

  • M0: 100 per second
  • M2: 200 per second
  • M5: 500 per second
Automatic Pause of Idle Clusters
Atlas automatically pauses M0 clusters after 60 days of inactivity where there are zero connections to the cluster. You can resume the cluster at any time.
Driver
Description
Drivers that use a JRE or JDK'

Due to an issue with TLS 1.3 support in the Java JDK' (JDK-8236039), upgrade the JDK' that supports the driver you use to connect to Atlas.

Minimum versions of the JDK' include:

14u-cpu
14.0.2
13.0.3
11.0.8-oracle
11.0.7
8u261
emb-8u261

To check if other Java-based languages, libraries, and drivers support the change to TLS 1.3, refer to their documentation:

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