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

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

Atlas supports the following cloud service providers and regions for deploying M0 clusters:

Cloud Provider	Supported Regions
AWS	`N. Virginia (us-east-1)` `Frankfurt (eu-central-1)` `Singapore (ap-southeast-1)` `Mumbai (ap-south-1)`
GCP	`Iowa (us-central-1)` `Belgium (europe-west-1)` `Singapore (asia-southeast1)`

Atlas supports the following cloud service providers and regions for deploying M2/M5 clusters:

Cloud Provider	Supported Regions
AWS	`N. Virginia (us-east-1)` `N. California (us-west-1)` `Oregon (us-west-2)` `Singapore (ap-southeast-1)` `Sydney (ap-southeast-2)` `Mumbai (ap-south-1)`
GCP	`Iowa (us-central1)` `Belgium (europe-west1)` `Taiwan (asia-east1)`
Azure	`Virginia (eastus2)` `Ireland (northeurope)`

MongoDB Version and Storage Engine Atlas locks the MongoDB version and storage engine for M0/M2/M5 clusters to MongoDB 3.6 with WiredTiger.

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.

Encryption at Rest using your Key Management You cannot configure Encryption at Rest Using Your Key Management 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.
Data Transfer Limits	`M0/M2/M5` clusters limit the total data transferred into or out of the cluster as follows: `M0`: 10 GB per week `M2`: 20 GB per week `M5`: 50 GB per week 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. For example, $where and map-reduce are not supported.
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.

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