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MongoDB Atlas



Notification sent by Atlas when your database operations or server usage reach thresholds that affect cluster performance. To learn what conditions you can set to trigger alerts, see Review Alert Conditions.


See also:

analytics node
Specialized read-only node that can isolate queries which you do not want to affect your operational workload. Analytics nodes are useful for handling analytic data such as reporting queries executed by BI tools. You can host analytics nodes in dedicated geographic regions to optimize read performance and reduce latency.

Communication protocol facilitating interaction between the client and MongoDB Atlas. You can use the Atlas Administration API to automate many of the tasks performed in the Atlas UI.


See also:

  • Atlas Programmatic Access

  • Atlas Administration API Specification

App Services

Serverless platform that enables developers to quickly build applications without having to set up server infrastructure. Atlas App Services automatically integrates the connection to your Atlas cluster databases, allowing for seamless interaction between your application and data.

Fine-grained text indexing enabling advanced text search on your data without any additional required management. Atlas Search provides options for several kinds of text analyzers, score-based results ranking, and a rich query language.

Atlas user

Account used to access the Atlas application. You can grant Atlas users access to Atlas organizations, projects, or both, with certain permissions defined by user roles. Atlas users are different than database users. Atlas users do not provide access to any MongoDB databases.

Atlas user role

Set of permissions granted to an Atlas user. You can grant permissions at the organization or project level.



Configurable option to have your cluster automatically increase or decrease its cluster tier, storage capacity, or both in response to cluster usage.


Copy of your data that encapsulates the state of your cluster at a given time. Backups provide a safety measure in the case of data loss events.

Atlas provides the following fully-managed methods for backups:

cloud backups

Localized cluster backup storage using the native snapshot functionality of the cluster's cloud service provider.

Atlas supports Cloud Backups for clusters served on:

Set of nodes comprising a MongoDB deployment. In Atlas, clusters can be replica sets or sharded deployments.
cluster class

Configurable for M40+ clusters hosted on AWS.

Storage class of your cluster. Your selected class affects cluster storage performance and cluster costs. You can choose one of the following classes:

  • Low CPU

  • General

  • Local NVMe SSD

cluster tier

Dictates the memory, storage, vCPUs, and IOPS specification for each data-bearing server in the cluster. Cluster storage size and overall performance increase as the cluster tier increases.

custom role

Custom set of MongoDB privilege actions and MongoDB roles that you can save and assign to database users. Create custom roles when Atlas's built-in roles don't describe your desired set of privileges.

Data Explorer

Tool within Atlas to view and interact with cluster data. You can also use the Data Explorer to manage indexes and run aggregation pipelines to process your data.

Data Federation

MongoDB's solution for querying data stored in low-cost S3 buckets, Atlas clusters, HTTP endpoints, and Atlas Data Lake datasets using the MongoDB Query Language. Analytics applications can use Atlas Data Federation to make use of archived data for their data processing needs.

Data Lake

MongoDB's solution for storing extracted data in in an analytic-optimized storage service. Atlas Data Lake provides analytic storage format optimized for flat or nested data with low latency query performance.


See also:

Database user

Credentials used to authenticate a client to access a MongoDB cluster. You can assign privileges to a database user to determine that user's access level to a cluster. Database users are different from Atlas users. Database users have access to MongoDB deployments, not the Atlas application.

Database user privileges

Set of privilege actions or roles granted to a database user. You can assign database user privileges at the cluster, database, and collection level.


See also:

dead letter queue
A dead letter queue is a collection within an Atlas database that stores documents that throw errors during ingestion.
dedicated cluster

Cluster category containing clusters of tier M10 and greater.

Recommended environments
M10 and M20
  • Development

  • Low-traffic production

M30 and greater
A group of MongoDB servers containing your data. Atlas-managed clusters are either clusters (replica sets or sharded clusters) or serverless instances.
electable node
Node which is eligible to become the primary member of your replica set. Atlas prioritizes nodes in the Highest Priority region for primary eligibility during elections. To ensure reliable elections, the total number of electable nodes across an entire region must be 3, 5, or 7.
encryption key

Random string of bits generated specifically to encrypt and decrypt data.

Atlas Project Owners can configure an additional layer of encryption on their data in addition to the default encryption at rest that Atlas provides. Project owners can use their Atlas-compatible customer key management provider with the MongoDB encrypted storage engine.

Atlas supports the following customer key management providers when configuring Encryption at Rest:

Free Tier

Free-to-use cluster tier that provides a small-scale development environment to host your data. free clusters never expire, and provide access to a subset of Atlas features and functionality. free clusters might also be referred to by their instance size, M0.

Global Cluster

Clusters with defined geographic zones to support location-aware read and write operations for globally distributed application instances and clients. You can enable global sharding on clusters of tier M30 and greater.

global write zone

Geographic zone representing a subset of your global cluster distribution. Each Global Cluster supports up to 9 distinct global write zones. Each zone consists of one Highest Priority region and one or more electable, read-only, or analytics regions.

The available geographic regions depend on the selected cloud service provider.

See project.
group ID
See project ID.
Highest Priority region

Region in a multi-region cluster which Atlas prioritizes for primary eligibility during elections.


Estimated performance improvement of an index that Performance Advisor suggests.

interface endpoint

AWS VPC endpoint with a private IP address that sends traffic to the Atlas private endpoint service over AWS PrivateLink.

IP access list

List of IP addresses and CIDR blocks with access to clusters within an Atlas project. For client connections over the public Internet, Atlas allows connections to a cluster only from entries in the corresponding project's IP access list. The access list may have up to 200 entries.

Atlas also allows client connections over nonpublic networking, such network peering connections or private endpoints. These types of connections work irrespective of the IP access list. To learn more, see Set Up a Network Peering Connection and Learn About Private Endpoints in Atlas.


Cross-platform protocol used to authenticate users and authorize them to access data on a cluster. You can use Atlas to manage user authentication and authorization from all MongoDB clients using your own LDAP server over TLS. A single LDAPS configuration applies to all clusters in an Atlas project.

legacy backups

Incremental backups of your cluster taken by Atlas that ensure that your backups are typically just a few seconds behind the operational system. You can restore your cluster to a state from a selected point in time within the last 24 hours.


Legacy Backup Deprecated

Effective 23 March 2020, all new clusters can only use Cloud Backups.

When you upgrade to 5.0, your backup system upgrades to cloud backup if it is currently set to legacy backup. After this upgrade:

String that contains the information necessary to connect from Cloud Manager or Ops Manager to Atlas during a live migration from a Cloud Manager or Ops Manager deployment to a cluster in Atlas.

When you are ready to live migrate data from a Cloud Manager or Ops Manager deployment, you generate a link-token in Atlas and then enter it in your Cloud Manager or Ops Manager organization's settings. You use the same link-token to migrate each deployment in your Cloud Manager or Ops Manager organization sequentially, one at a time. You can generate multiple link-tokens in Atlas. Use one unique link-token for each Cloud Manager or Ops Manager organization.

Live Migration

Process to seamlessly move an existing source replica set or sharded cluster to Atlas. During the live migration process, Atlas keeps the target cluster in sync with the remote source until you cut your applications over to the Atlas cluster. Atlas offers two modes of live migration:

  • Push live migration, known in the Atlas user interface as Live Migration from Ops Manager or Cloud Manager, where Atlas pushes a deployment from Cloud Manager or Ops Manager to Atlas.

  • Pull live migration, known in the Atlas user interface as General Live Migration, where Atlas pulls a deployment from a cloud or on-premise deployment to Atlas.

maintenance window

Day and time of the week when Atlas should start weekly maintenance on your cluster. You can set your maintenance window in your Project Settings.


Maintenance Window Considerations

Urgent Maintenance Activities
Urgent maintenance activities such as security patches cannot wait for your chosen window. Atlas will start those maintenance activities when needed.
Ongoing Maintenance Operations
Once maintenance is scheduled for your cluster, you cannot change your maintenance window until the current maintenance efforts have completed.
Maintenance Requires Replica Set Elections
Atlas performs maintenance the same way as the maintenance procedure described in the MongoDB Manual. This procedure requires at least one replica set election during the maintenance window per replica set.
Maintenance Starts As Close to the Hour As Possible
Maintenance always begins as close to the scheduled hour as possible, but in-progress cluster updates or unexpected system issues could delay the start time.
MongoDB Charts

Visualization tool for your Atlas data. You can launch MongoDB Charts from your Atlas cluster and view your data with the Charts application to begin visualizing your data.


See also:

multi-region cluster

Atlas cluster spanning multiple geographic regions. Multi-region clusters can increase availability and improve performance by routing application queries to the most appropriate geographic regions.

Multi-region clusters must contain electable nodes.

Multi-region clusters may contain read-only nodes and analytics nodes.

Combination of the database name and the collection name in the database.collection format.
Namespace Insights

Atlas tool that monitors collection-level query latency. You can view query latency metrics and statistics for certain hosts and operation types. Manage pinned namespaces and choose up to five namespaces to show in the corresponding query latency charts.

network peering connection

Process by which two Internet networks connect and exchange traffic. You can directly peer your VPC with the Atlas VPC created for your MongoDB clusters. Using network peering, your application servers can directly connect to Atlas while remaining isolated from public networks.

NVMe storage

Available for M40+ clusters hosted on AWS

For applications hosted on AWS which require low-latency and high-throughput IO, you can use the NVMe cluster class. The NVMe cluster class leverages a unique data protocol to greatly improve data access speeds.

NVMe clusters use a hidden secondary node consisting of a provisioned volume with high throughput and IOPS to facilitate backup.


Logical grouping of Atlas projects. You can leverage an organization to manage billing, users, and security settings for the projects it contains.

  • Billing happens at the organization level while preserving visibility into usage in each project.

  • You can view all projects within an organization.

  • You can use teams to bulk assign organization users to projects within the organization.


See also:

organization ID
Unique 24-digit hexadecimal string used to identify your Atlas organization. The Return All Organizations endpoint returns the ID of all organizations that the authenticated user executing the API call can access.
Performance Advisor

Atlas tool that monitors slow queries executed on your cluster and suggests indexes to improve query performance. Each index that the Performance Advisor suggests include an Impact score indicating the potential performance improvement that index would bring.

In a replica set, the primary is the member that receives all write operations. In multi-region clusters, Atlas prioritizes nodes in the Highest Priority region for primary eligibility during elections.

Logical grouping of clusters. You can have multiple clusters within a single project and multiple projects within a single organization.


Project is synonymous with group.

project ID

Unique 24-digit hexadecimal string used to identify your Atlas project. The Get All Projects API endpoint returns the ID of all projects that the authenticated user executing the API call can access.


Project ID is synonymous with group ID.

Query Profiler

Atlas tool that diagnoses and monitors performance issues in your cluster. The Query Profiler can expose long-running queries and their performance statistics. You can filter the data returned by the Query Profiler to hone in on specific namespaces and operation types.

read-only node
Replica set in a dedicated geographic region that supplements your electable node regions. You can use read-only nodes to localize data where it is most frequently read to improve performance.
Real-Time Performance Panel

Atlas monitoring service that displays current network traffic, database operations on your clusters, and hardware statistics about your host machines. Use the RTPP to visually evaluate query execution times, monitor network activity, and discover potential replication lag on secondary members of replica sets.

replica set

Group of MongoDB servers that maintain the same data set. Replica sets provide redundancy, high availability, and are the basis for all production deployments.


See also:

rolling restart
Process that restarts all nodes in the cluster in sequence. To maintain cluster availability, Atlas restarts one node at a time starting with a secondary node. Atlas always maintains a primary node until the rolling restart completes.
sharded cluster

Set of nodes comprising a sharded MongoDB deployment. A sharded cluster consists of config servers, shards, and one or more mongos routing processes.

shared cluster

Cluster category containing M0 (Free Tier), M2, and M5 tier clusters. Shared clusters are generally used for development and small production workloads.


Backup of your data captured at a specific interval and stored in a backup data center. The Snapshot Schedule determines the interval for taking snapshots and how long to store them.


Group of Atlas users in the same organization. You can use teams to grant access to the same group of Atlas users across multiple projects. All users in the team share the same project access.


Atlas users can belong to multiple teams.


State of a deployment of MongoDB instances, which includes the following details:

  • Type of deployment (standalone, replica set, or sharded cluster)

  • Availability of servers

  • Role of each server (primary, secondary, config server, or mongos)

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