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mongodump

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mongodump is a utility that creates a binary export of a database's contents. mongodump can export data from:

  • Standalone deployments

  • Replica sets

  • Sharded clusters

  • Serverless instances

You can use the MongoDB Database Tools to migrate from a self-hosted deployment to MongoDB Atlas. MongoDB Atlas is the fully managed service for MongoDB deployments in the cloud. To learn more, see Seed with mongorestore.

To learn all the ways you can migrate to MongoDB Atlas, see Migrate or Import Data.

mongodump can connect to mongod and mongos instances.

You can restore the BSON files generated from mongodump into MongoDB deployments running the same or newer version as the source deployment. However, restoring files into a newer version deployment is not the recommended way to upgrade your deployment. To learn how to upgrade your deployment, see the upgrade documentation.

Run mongodump from the system command line, not the mongo shell.

Tip

See also:

mongorestore, which allows you to import data that was exported from mongodump.

If you are archiving stale data to save on storage costs, consider Online Archive in MongoDB Atlas. Online Archive automatically archives infrequently accessed data to fully-managed S3 buckets for cost-effective data tiering.

mongodump dumps:

  • Collection documents, metadata, and options.

  • Index definitions.

  • Writes that occur during the export, if run with the mongodump --oplog option.

mongodump dumps data to a directory or a binary archive file.

Example mongodump directory dump structure and files:

dump
├── easternSalesDatabase
│ ├── sales.bson
│ ├── sales.metadata.json
│ └── salesByMonthView.metadata.json
├── westernSalesDatabase
│ ├── sales.bson
│ ├── sales.metadata.json
│ └── salesByMonthView.metadata.json
└── oplog.bson

For a directory dump, mongodump creates:

  • A root directory with the default name dump. You can set the name with the mongodump --out option.

  • A subdirectory in the root directory for each database. For example, if a database name is easternSalesDatabase, the subdirectory name is also easternSalesDatabase.

  • A BSON file with documents for each collection. For example, if a collection name is sales, the BSON file is sales.bson.

  • A metadata JSON file for each collection in each database directory. For example, a metadata sales.metadata.json file. The file contains a document with the exported collection metadata, options, and indexes.

  • A metadata JSON file for each view. For example, a metadata salesByMonthView.metadata.json file. A view doesn't have a BSON file.

  • An optional oplog oplog.bson file, located in the root directory, which contains write operations that occurred during the mongodump run. To output an oplog.bson file, use the mongodump --oplog option.

If you use the mongodump --gzip option, the BSON files and JSON metadata files are compressed. The compressed exported files have bson.gz and metadata.json.gz at the end of the names.

To dump data to a binary archive file, use the mongodump --archive option. mongodump creates a binary file that contains the archived data.

mongodump syntax:

mongodump <options> <connection-string>

To connect to a local MongoDB instance running on port 27017 and use the default settings to export the content, run mongodump without any command-line options:

mongodump

To specify a host and/or port of the MongoDB instance, you can:

  • Specify the hostname and port in the --uri connection string option:

    mongodump --uri="mongodb://mongodb0.example.com:27017" [additional options]
  • Specify the hostname and port in the --host option:

    mongodump --host="mongodb0.example.com:27017" [additional options]
  • Specify the hostname and port in the --host and --port options:

    mongodump --host="mongodb0.example.com" --port=27017 [additional options]

To connect to a replica set to export its data, you can:

  • Specify the replica set name and members in the --uri connection string option:

    mongodump --uri="mongodb://mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com:27017/?replicaSet=myReplicaSetName" [additional options]
  • Specify the replica set name and members in the --host option:

    mongodump --host="myReplicaSetName/mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com" [additional options]

By default, mongodump reads from the primary of the replica set. To override the default, you can specify the read preference:

  • You can specify the read preference in the --uri connection string option:

    mongodump --uri="mongodb://mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com:27017/?replicaSet=myReplicaSetName&readPreference=secondary" [additional options]

    If specifying the read preference tags, include the readPreferenceTags option:

    mongodump --uri="mongodb://mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com:27017/?replicaSet=myReplicaSetName&readPreference=secondary&readPreferenceTags=region:east" [additional options]
  • You can specify the read preference using the --readPreference command-line option. The command-line option takes a string if specifying only the read preference mode:

    mongodump --host="myReplicaSetName/mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com:27017" --readPreference=secondary [additional options]

    Or, the command-line option can take a quote-enclosed document '{ mode: <mode>, tagSets: [ <tag1>, ... ], maxStalenessSeconds:<num>}' to specify the mode, the optional read preference tag sets, and the optional maxStalenessSeconds:

    mongodump --host="myReplicaSetName/mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com:27017" --readPreference='{mode: "secondary", tagSets: [ { "region": "east" } ]}' [additional options]

To connect to a sharded cluster to export its data, you can:

  • Specify the hostname of the mongos instance in the --uri connection string option:

    mongodump --uri="mongodb://mongos0.example.com:27017" [additional options]
  • Specify the hostname and port of the mongos instance in the --host option:

    mongodump --host="mongos0.example.com:27017" [additional options]

By default, mongodump reads from the primary of the shard replica set. To override the default, you can specify the read preference:

  • You can specify the read preference in the --uri connection string option:

    mongodump --uri="mongodb://mongos0.example.com:27017/?readPreference=secondary" [additional options]

    If specifying the read preference tags, include the readPreferenceTags option:

    mongodump --uri="mongodb://mongos0.example.com:27017/?readPreference=secondary&readPreferenceTags=region:east" [additional options]
  • You can specify the read preference using the --readPreference command-line option. The command-line option takes a string if specifying only the read preference mode:

    mongodump --host="mongos0.example.com:27017" --readPreference=secondary [additional options]

    Or, the command-line option can take a quote-enclosed document '{ mode: <mode>, tagSets: [ <tag1>, ... ], maxStalenessSeconds: <num>}' to specify the mode, the optional read preference tag sets, and the optional maxStalenessSeconds:

    mongodump --host="mongos0.example.com:27017" --readPreference='{mode: "secondary", tagSets: [ { "region": "east" } ]}' [additional options]
--help

Returns information on the options and use of mongodump.

--verbose, -v

Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the -v form by including the option multiple times. For example: -vvvvv.

--quiet

Runs mongodump in a quiet mode that attempts to limit the amount of output.

This option suppresses:

  • Output from database commands

  • Replication activity

  • Connection accepted and closed events

  • All logs, including error messages, except for those that occur when parsing options

--version

Returns the mongodump release number.

--config=<filename>

New in version 100.3.0.

Specifies the full path to a YAML configuration file containing sensitive values for the following options to mongodump:

This is the recommended way to specify a password to mongodump, aside from specifying it through a password prompt.

The configuration file takes the following form:

password: <password>
uri: mongodb://mongodb0.example.com:27017
sslPEMKeyPassword: <password>

Specifying a password to the password: field and providing a connection string in the uri: field which contains a conflicting password will result in an error.

Be sure to secure this file with appropriate filesystem permissions.

Note

If you specify a configuration file with --config and also use the --password, --uri or --sslPEMKeyPassword option to mongodump, each command line option overrides its corresponding option in the configuration file.

--uri=<connectionString>

Specifies the resolvable URI connection string of the MongoDB deployment, enclosed in quotes:

--uri="mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database][?options]]"

Starting with version 100.0 of mongodump, the connection string may alternatively be provided as a positional parameter, without using the --uri option:

mongodump mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database][?options]]

As a positional parameter, the connection string may be specified at any point on the command line, as long as it begins with either mongodb:// or mongodb+srv://. For example:

mongodump --username joe --password secret1 mongodb://mongodb0.example.com:27017 --ssl

Only one connection string can be provided. Attempting to include more than one, whether using the --uri option or as a positional argument, will result in an error.

For information on the components of the connection string, see the Connection String URI Format documentation.

Note

Some components in the connection string may alternatively be specified using their own explicit command-line options, such as --username and --password. Providing a connection string while also using an explicit option and specifying conflicting information will result in an error.

Note

If using mongodump on Ubuntu 18.04, you may experience a cannot unmarshal DNS error message when using SRV connection strings (in the form mongodb+srv://) with the --uri option. If so, use one of the following options instead:

Warning

On some systems, a password provided in a connection string with the --uri option may be visible to system status programs such as ps that may be invoked by other users. Consider instead:

  • omitting the password in the connection string to receive an interactive password prompt, or

  • using the --config option to specify a configuration file containing the password.

--host=<hostname><:port>, -h=<hostname><:port>

Default: localhost:27017

Specifies the resolvable hostname of the MongoDB deployment. By default, mongodump attempts to connect to a MongoDB instance running on the localhost on port number 27017.

To connect to a replica set, specify the replSetName and a seed list of set members, as in the following:

--host=<replSetName>/<hostname1><:port>,<hostname2><:port>,<...>

When specifying the replica set list format, mongodump always connects to the primary.

You can also connect to any single member of the replica set by specifying the host and port of only that member:

--host=<hostname1><:port>

If you use IPv6 and use the <address>:<port> format, you must enclose the portion of an address and port combination in brackets. For example: [<address>].

Alternatively, you can also specify the hostname directly in the URI connection string. Providing a connection string while also using --host and specifying conflicting information will result in an error.

--port=<port>

Default: 27017

Specifies the TCP port on which the MongoDB instance listens for client connections.

Alternatively, you can also specify the port directly in the URI connection string. Providing a connection string while also using --port and specifying conflicting information will result in an error.

--ssl

Enables a connection to a mongod or mongos that has TLS/SSL support enabled.

Alternatively, you can also configure TLS/SSL support directly in the URI connection string. Providing a connection string while also using --ssl and specifying conflicting information will result in an error.

--sslCAFile=<filename>

Specifies the .pem file that contains the root certificate chain from the Certificate Authority. Specify the file name of the .pem file using relative or absolute paths.

Alternatively, you can also specify the .pem file directly in the URI connection string. Providing a connection string while also using --sslCAFile and specifying conflicting information will result in an error.

--sslPEMKeyFile=<filename>

Specifies the .pem file that contains both the TLS/SSL certificate and key. Specify the file name of the .pem file using relative or absolute paths.

This option is required when using the --ssl option to connect to a mongod or mongos that has CAFile enabled without allowConnectionsWithoutCertificates.

Alternatively, you can also specify the .pem file directly in the URI connection string. Providing a connection string while also using --sslPEMKeyFile and specifying conflicting information will result in an error.

--sslPEMKeyPassword=<value>

Specifies the password to de-crypt the certificate-key file (i.e. --sslPEMKeyFile). Use the `--sslPEMKeyPassword option only if the certificate-key file is encrypted. In all cases, mongodump will redact the password from all logging and reporting output.

If the private key in the PEM file is encrypted and you do not specify the --sslPEMKeyPassword option, mongodump will prompt for a passphrase. See TLS/SSL Certificate Passphrase.

Alternatively, you can also specify the password directly in the URI connection string. Providing a connection string while also using --sslPEMKeyPassword and specifying conflicting information will result in an error.

Warning

On some systems, a password provided directly using the --sslPEMKeyPassword option may be visible to system status programs such as ps that may be invoked by other users. Consider using the --config option to specify a configuration file containing the password instead.

--sslCRLFile=<filename>

Specifies the .pem file that contains the Certificate Revocation List. Specify the file name of the .pem file using relative or absolute paths.

--sslAllowInvalidCertificates

Bypasses the validation checks for server certificates and allows the use of invalid certificates. When using the allowInvalidCertificates setting, MongoDB logs as a warning the use of the invalid certificate.

Warning

Although available, avoid using the --sslAllowInvalidCertificates option if possible. If the use of --sslAllowInvalidCertificates is necessary, only use the option on systems where intrusion is not possible.

Connecting to a mongod or mongos instance without validating server certificates is a potential security risk. If you only need to disable the validation of the hostname in the TLS/SSL certificates, see --sslAllowInvalidHostnames.

Alternatively, you can also disable certificate validation directly in the URI connection string. Providing a connection string while also using --sslAllowInvalidCertificates and specifying conflicting information will result in an error.

--sslAllowInvalidHostnames

Disables the validation of the hostnames in TLS/SSL certificates. Allows mongodump to connect to MongoDB instances even if the hostname in their certificates do not match the specified hostname.

Alternatively, you can also disable hostname validation directly in the URI connection string. Providing a connection string while also using --sslAllowInvalidHostnames and specifying conflicting information will result in an error.

--username=<username>, -u=<username>

Specifies a username with which to authenticate to a MongoDB database that uses authentication. Use in conjunction with the --password <mongodump --password> and --authenticationDatabase <mongodump --authenticationDatabase> options.

Alternatively, you can also specify the username directly in the URI connection string. Providing a connection string while also using --username and specifying conflicting information will result in an error.

If connecting to a MongoDB Atlas cluster using the MONGODB-AWS authentication mechanism, you can specify your AWS access key ID in:

See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials for an example of each.

--password=<password>, -p=<password>

Specifies a password with which to authenticate to a MongoDB database that uses authentication. Use in conjunction with the --username <mongodump --username> and --authenticationDatabase <mongodump --authenticationDatabase> options.

To prompt the user for the password, pass the --username <mongodump --username> option without --password <mongodump --password> or specify an empty string as the --password <mongodump --password> value, as in --password "" .

Alternatively, you can also specify the password directly in the URI connection string. Providing a connection string while also using --password and specifying conflicting information will result in an error.

If connecting to a MongoDB Atlas cluster using the MONGODB-AWS authentication mechanism, you can specify your AWS secret access key in:

See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials for an example of each.

Warning

On some systems, a password provided directly using the --password option may be visible to system status programs such as ps that may be invoked by other users. Consider instead:

  • omitting the --password option to receive an interactive password prompt, or

  • using the --config option to specify a configuration file containing the password.

--awsSessionToken=<AWS Session Token>

If connecting to a MongoDB Atlas cluster using the MONGODB-AWS authentication mechanism, and using session tokens in addition to your AWS access key ID and secret access key, you can specify your AWS session token in:

See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials for an example of each.

Only valid when using the MONGODB-AWS authentication mechanism.

--authenticationDatabase=<dbname>

Specifies the authentication database where the specified --username <mongodump --username> has been created. See Authentication Database.

If you do not specify an authentication database, mongodump assumes that the database specified to export holds the user's credentials.

If you do not specify an authentication database or a database to export, mongodump assumes the admin database holds the user's credentials.

If using the GSSAPI (Kerberos), PLAIN (LDAP SASL), or MONGODB-AWS authentication mechanisms, you must set --authenticationDatabase to $external.

Alternatively, you can also specify the authentication database directly in the URI connection string. Providing a connection string while also using --authenticationDatabase and specifying conflicting information will result in an error.

--authenticationMechanism=<name>

Default: SCRAM-SHA-1

Specifies the authentication mechanism the mongodump instance uses to authenticate to the mongod or mongos.

Changed in version 100.1.0: Starting in version 100.1.0, mongodump adds support for the MONGODB-AWS authentication mechanism when connecting to a MongoDB Atlas cluster.

Value
Description

RFC 7677 standard Salted Challenge Response Authentication Mechanism using the SHA-256 hash function.

Requires featureCompatibilityVersion set to 4.0.

MongoDB TLS/SSL certificate authentication.
MONGODB-AWS

External authentication using AWS IAM credentials for use in connecting to a MongoDB Atlas cluster. See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials.

New in version 100.1.0.

GSSAPI (Kerberos)
External authentication using Kerberos. This mechanism is available only in MongoDB Enterprise.
PLAIN (LDAP SASL)
External authentication using LDAP. You can also use PLAIN for authenticating in-database users. PLAIN transmits passwords in plain text. This mechanism is available only in MongoDB Enterprise.

Alternatively, you can also specify the authentication mechanism directly in the URI connection string. Providing a connection string while also using --authenticationMechanism and specifying conflicting information will result in an error.

--gssapiServiceName

Specify the name of the service using GSSAPI/Kerberos. Only required if the service does not use the default name of mongodb.

This option is available only in MongoDB Enterprise.

Alternatively, you can also specify the service name directly in the URI connection string. Providing a connection string while also using --gssapiServiceName and specifying conflicting information will result in an error.

--gssapiHostName

Specify the hostname of a service using GSSAPI/Kerberos </core/kerberos>. Only required if the hostname of a machine does not match the hostname resolved by DNS.

This option is available only in MongoDB Enterprise.

--db=<database>, -d=<database>

Specifies a database to backup. If you do not specify a database, mongodump copies all databases in this instance into the dump files.

Alternatively, you can also specify the database directly in the URI connection string. Providing a connection string while also using --db and specifying conflicting information will result in an error.

--collection=<collection>, -c=<collection>

Specifies a collection to backup. If you do not specify a collection, this option copies all collections in the specified database or instance to the dump files.

--query=<json>, -q=<json>

Provides a JSON document as a query that optionally limits the documents included in the output of mongodump. To use the --query option, you must also specify the --collection <mongodump --collection> option.

You must enclose the query document in single quotes ('{ ... }') to ensure that it does not interact with your shell environment.

The query must be in Extended JSON v2 format (either relaxed or canonical/strict mode), including enclosing the field names and operators in quotes. For example:

mongodump -d=test -c=records -q='{ "a": { "$gte": 3 }, "date": { "$lt": { "$date": "2016-01-01T00:00:00.000Z" } } }'

To use $regex with mongodump, use the following syntax:

mongodump -d=sample_mflix -c=movies -q='{ "year": { "$regex": "20" } }'

Note

When you use the --query option on a time series collection, you can only query the field specified as the metaField.

--queryFile=<path>

Specifies the path to a file containing a JSON document as a query filter that limits the documents included in the output of mongodump. --queryFile enables you to create query filters that are too large to fit in your terminal's buffer.

Note

When you use the --queryFile option on a time series collection, you can only query the field specified as the metaField.

--readPreference=<string|document>

Default: primary

Specifies the read preference for mongodump. The --readPreference option can take:

  • A string if specifying only the read preference mode:

    --readPreference=secondary
  • A quote-enclosed document to specify the mode, the optional read preference tag sets, and the optional maxStalenessSeconds:

    --readPreference='{mode: "secondary", tagSets: [ { "region": "east" } ], maxStalenessSeconds: 120}'

    If specifying the maxStalenessSeconds, the value must be greater than or equal to 90.

mongodump defaults to primary read preference.

If the read preference is also included in the --uri connection string <--uri>, the command-line --readPreference overrides the read preference specified in the URI string.

--gzip

Compresses the output. If mongodump outputs to the dump directory, the new feature compresses the individual files. The files have the suffix .gz.

If mongodump outputs to an archive file or the standard out stream, the new feature compresses the archive file or the data output to the stream.

--out=<path>, -o=<path>

Specifies the directory where mongodump will write BSON files for the dumped databases. By default, mongodump saves output files in a directory named dump in the current working directory.

To send the database dump to standard output, specify "-" instead of a path. Write to standard output if you want process the output before saving it, such as to use gzip to compress the dump. When writing standard output, mongodump does not write the metadata that writes in a <dbname>.metadata.json file when writing to files directly.

You cannot use the --archive option with the --out option.

--archive=<file>

Writes the output to a specified archive file or, if the archive file is unspecified, writes to the standard output (stdout). An archive file is a single-file alternative to multiple BSON files.

  • To output the dump to an archive file, run mongodump with the --archive <mongodump --archive> option and the archive filename.

    mongodump --archive=<file>
  • To output the dump to the standard output stream in order to pipe to another process, run mongodump with the --archive <mongodump --archive> option but omit the filename.

    mongodump --archive

You cannot use the --archive <mongodump --archive> option with the --out <mongodump --out> option.

Note

If mongodump writes to an archive file, mongodump performance can improve. For more information on mongodump performance impacts, see Output Format Considerations.

--oplog

Creates a file named oplog.bson as part of the mongodump output. The oplog.bson file, located in the top level of the output directory, contains oplog entries that occur during the mongodump operation.

To apply oplog entries from the oplog.bson file in the restore operation, use mongorestore --oplogReplay. You can use mongodump --oplog together with mongorestore --oplogReplay to ensure the data is current and has all the writes that occurred during the dump.

Without --oplog, if there are write operations during the dump operation, the dump will not reflect a single moment in time. Changes made to the database during the update process can affect the output of the backup.

To back up individual replica sets while still accepting writes, use --oplog. To back up sharded clusters with mongodump, see Back Up a Sharded Cluster with Database Dumps.

Important

A mongodump running with --oplog fails if a client issues any of the listed operations during the dump process.

--oplog has no effect when running mongodump on a mongos instance to dump the entire contents of a sharded cluster.

--oplog only works against nodes that maintain an oplog. This includes all members of a replica set.

--oplog does not dump the oplog collection.

Note

To use mongodump with --oplog, you must create a full dump of a replica set member. mongodump with --oplog fails if you use any of the following options to limit the data to be dumped:

  • --db

  • --collection

  • --dumpDbUsersAndRoles

  • --query

--dumpDbUsersAndRoles

Includes user and role definitions in the database's dump directory when performing mongodump on a specific database. This option applies only when you specify a database in the --db option. MongoDB always includes user and role definitions when mongodump applies to an entire instance and not just a specific database.

--excludeCollection=<string>

Excludes the specified collection from the mongodump output. To exclude multiple collections, specify the --excludeCollection multiple times.

--excludeCollectionsWithPrefix=<string>

Excludes all collections with a specified prefix from the mongodump outputs. To specify multiple prefixes, specify the --excludeCollectionsWithPrefix multiple times.

--numParallelCollections=<int>, -j=<int>

Default: 4

Number of collections mongodump should export in parallel.

--viewsAsCollections

When specified, mongodump exports views as collections.

Note

Only views are exported. By default, mongodump only exports a view's metadata. To export the documents in a view, use the --viewsAsCollections option.

For each view, mongodump creates a BSON file containing the documents in the view. If you use mongorestore with a BSON file created by mongodump, the view is restored as a collection.

If you do not include --viewsAsCollections, mongodump captures each view's metadata. If you include a view's metadata file in a mongorestore operation, the view is recreated.

For more information about mongodump, see:

For a tutorial, see Back Up a Sharded Cluster with Database Dumps.

For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.

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