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

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

Atlas can deploy M0 Free Tier clusters to the Amazon Web Services us-east-1 (N. Virginia, USA) or eu-central-1 (Frankfurt, Germany) region. This does not affect other clusters in the Atlas project.

Atlas can deploy M2 and M5 clusters to a subset of regions on Amazon Web Services, Google Cloud Platform, and Microsoft Azure.

MongoDB Version For clusters built after April 23, 2018, the MongoDB version is set to MongoDB 3.6 with WiredTiger. You cannot modify the MongoDB version of M0 Free Tier or M2/M5 shared clusters.
Instance Size You must select the M0 instance size to deploy a Free Tier cluster.
Instance Memory You cannot configure memory for M0 Free Tier or M2/M5 shared instances.
Instance Storage You cannot configure storage size for M0 Free Tier or M2/M5 shared instances.
Replication Factor Replication Factor is set to 3 Nodes and cannot be modified for M0 Free Tier, or M2/M5 shared clusters.
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 or M2/M5 shared clusters.
Test Failovers You cannot perform primary failover testing on M0 Free Tier or M2/M5 shared clusters.
Database Auditing You cannot configure Set up Database Auditing on M0 Free Tier or M2/M5 shared clusters.

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

Aggregation Atlas Free Tier clusters do not support the allowDiskUse option for the aggregation command or its helper method.
Throughput Maximum of 100 operations per second allowed for M0 Free Tier and M2/M5 shared clusters.
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 .
Connections M0 Free Tier and M2/M5 shared clusters are allowed a maximum of 100 connections.
Network bandwidth

Restricted to 2 x the storage size limit per week for both incoming and outgoing. That is:

  • M0: 1 GB per week
  • M2: 4 GB per week
  • M5: 10 GB per week
Javascript M0 Free Tier and M2/M5 shared clusters do not support server side javascript. For example, $where and map-reduce are not supported.
Data Explorer Data Explorer is not available for M0 Free Tier or M2/M5 shared clusters.
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.
Number of Free Tier clusters You can deploy at most one Free Tier cluster per Atlas project.
Database Commands

Certain database commands are unsupported or behavior differently in a Free Tier cluster. See Command Limitations in Free Tier Clusters for more information.

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

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.

Atlas Alerts

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

  • Connections
  • Logical Size
  • Network
  • Opscounter
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.
Database and Collections M0 Free Tier and M2/M5 shared clusters have a maximum of 100 databases and 500 collections total.
Cluster Persistance Atlas may terminate idle Free Tier clusters as per the Terms of Service.
VPC Peering M0 Free Tier and M2/M5 shared clusters do not support VPC peering.
Database Logs M0 Free Tier and M2/M5 shared clusters do not provide downloadable logs.
Auto-Expand Storage M0 Free Tier and M2/M5 shared clusters do not provide automatically scaling storage.
Performance Advisor M0 Free Tier and M2/M5 shared clusters do not provide access to the Performance Advisor.
Real-Time Performance Panel M0 Free Tier and M2/M5 shared clusters do not provide access to the Real-Time Performance Panel.