mongodump

Mac OSX Sierra and Go 1.6 Incompatibility

Users running on Mac OSX Sierra require the 3.2.10 or newer version of mongodump.

Synopsis

mongodump is a utility for creating a binary export of the contents of a database. mongodump can export data from either mongod or mongos instances.

mongodump can be a part of a backup strategy with mongorestore for partial backups based on a query, syncing from production to staging or development environments, or changing the storage engine of a standalone. However, the use of mongodump and mongorestore as a backup strategy can be problematic for sharded clusters and replica sets.

For an overview of mongodump in conjunction with mongorestore part of a backup and recovery strategy, see Back Up and Restore with MongoDB Tools.

Behavior

Data Exclusion

mongodump excludes the content of the local database in its output.

mongodump only captures the documents in the database in its backup data and does not include index data. mongorestore or mongod must then rebuild the indexes after restoring data.

Changed in version 3.4: MongoDB 3.4 added support for read-only views. By default, mongodump only captures a view’s metadata: it does not create a binary export of the documents included in the view. To capture the documents in a view use --viewsAsCollections.

Read Preference

Replica Sets

Changed in version 3.2.0: The choice of target or targets for the --host parameter affects the read preference of mongodump when connecting to a replica set.

  • If the string passed to --host is prefixed by the replica set name, mongodump reads from the primary replica set member by default. For example:

    --host "replSet/rep1.example.net:27017,rep2.example.net:27017,rep3.example.net:27017"
    
  • If the string passed to --host contains a list of mongod instances, but does not include the replica set name as a prefix to the host string, mongodump reads from the nearest node by default. For example:

    --host "rep1.example.net:27017,rep2.example.net:27017,rep3.example.net:27017"
    

Sharded Clusters

Changed in version 3.0.5: For a sharded cluster where the shards are replica sets, mongodump no longer prefers reads from secondary members when run against the mongos instance.

For sharded clusters, specify the hostname of a mongos for the --host option. mongodump reads from the primary replica set member on each shard replica set in the cluster.

Unsharded collections in a sharded cluster are stored on a primary shard. mongodump reads from the primary replica set member on the primary shard for any unsharded collections. Note: each database has its own primary shard.

Overwrite Files

mongodump overwrites output files if they exist in the backup data folder. Before running the mongodump command multiple times, either ensure that you no longer need the files in the output folder (the default is the dump/ folder) or rename the folders or files.

Data Compression Handling

When run against a mongod instance that uses the WiredTiger storage engine, mongodump outputs uncompressed data.

Working Set

mongodump can adversely affect performance of the mongod. If your data is larger than system memory, the mongodump will push the working set out of memory.

Required Access

To run mongodump against a MongoDB deployment that has access control enabled, you must have privileges that grant find action for each database to back up. The built-in backup role provides the required privileges to perform backup of any and all databases.

Changed in version 3.2.1: The backup role provides additional privileges to back up the system.profile collections that exist when running with database profiling. Previously, users required an additional read access on this collection.

Options

Changed in version 3.0.0: mongodump removed the --dbpath as well as related --directoryperdb and --journal options. You must use mongodump while connected to a mongod instance.

mongodump
mongodump
--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, (e.g. -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 events
  • connection closed events
--version

Returns the mongodump release number.

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

Default: localhost:27017

Specifies a resolvable hostname for the mongod to which to connect. By default, the 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:

<replSetName>/<hostname1><:port>,<hostname2><:port>,<...>

You can always connect directly to a single MongoDB instance by specifying the host and port number directly.

Changed in version 3.0.0: If you use IPv6 and use the <address>:<port> format, you must enclose the portion of an address and port combination in brackets (e.g. [<address>]).

--port <port>

Default: 27017

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

--ipv6

Removed in version 3.0.

Enables IPv6 support and allows mongodump to connect to the MongoDB instance using an IPv6 network. Prior to MongoDB 3.0, you had to specify --ipv6 to use IPv6. In MongoDB 3.0 and later, IPv6 is always enabled.

--ssl

New in version 2.6.

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

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

--sslCAFile <filename>

New in version 2.6.

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.

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

Warning

For SSL connections (--ssl) to mongod and mongos, if the mongodump runs without the --sslCAFile, mongodump will not attempt to validate the server certificates. This creates a vulnerability to expired mongod and mongos certificates as well as to foreign processes posing as valid mongod or mongos instances. Ensure that you always specify the CA file to validate the server certificates in cases where intrusion is a possibility.

--sslPEMKeyFile <filename>

New in version 2.6.

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.

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

--sslPEMKeyPassword <value>

New in version 2.6.

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, the 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, the mongodump will prompt for a passphrase. See SSL Certificate Passphrase.

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

--sslCRLFile <filename>

New in version 2.6.

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

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

--sslAllowInvalidCertificates

New in version 2.6.

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.

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

--sslAllowInvalidHostnames

New in version 3.0.

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

Changed in version 3.0: Most MongoDB distributions now include support for TLS/SSL. See Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients for more information about TLS/SSL and MongoDB.

--sslFIPSMode

New in version 2.6.

Directs the mongodump to use the FIPS mode of the installed OpenSSL library. Your system must have a FIPS compliant OpenSSL library to use the --sslFIPSMode option.

Note

FIPS-compatible SSL is available only in MongoDB Enterprise. See Configure MongoDB for FIPS for more information.

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

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

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

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

Changed in version 3.0.0: If you do not specify an argument for --password, mongodump returns an error.

Changed in version 3.0.2: If you wish mongodump to prompt the user for the password, pass the --username option without --password or specify an empty string as the --password value, as in --password "" .

--authenticationDatabase <dbname>

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

--authenticationMechanism <name>

Default: SCRAM-SHA-1

Changed in version 2.6: Added support for the PLAIN and MONGODB-X509 authentication mechanisms.

Changed in version 3.0: Added support for the SCRAM-SHA-1 authentication mechanism. Changed default mechanism to SCRAM-SHA-1.

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

Value Description
SCRAM-SHA-1 RFC 5802 standard Salted Challenge Response Authentication Mechanism using the SHA1 hash function.
MONGODB-CR MongoDB challenge/response authentication.
MONGODB-X509 MongoDB TLS/SSL certificate authentication.
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.
--gssapiServiceName

New in version 2.6.

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.

--gssapiHostName

New in version 2.6.

Specify the hostname of a service using GSSAPI/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.

--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.

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

--queryFile <path>

New in version 3.2.

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.

--readPreference <string>

Specify the read preference for mongodump.

See Read Preference Modes.

mongodump defaults to primary read preference when connected to a mongos or a replica set.

Otherwise, mongodump defaults to nearest.

Warning

Using a read preference other than primary with a connection to a mongos may produce inconsistencies, duplicates, or result in missed documents.

See Read Preference.

--forceTableScan

Forces mongodump to scan the data store directly: typically, mongodump saves entries as they appear in the index of the _id field. If you specify a query --query, mongodump will use the most appropriate index to support that query.

Use --forceTableScan to skip the index and scan the data directly. Typically there are two cases where this behavior is preferable to the default:

  1. If you have key sizes over 800 bytes that would not be present in the _id index.
  2. Your database uses a custom _id field.

When you run with --forceTableScan, mongodump does not use $snapshot. As a result, the dump produced by mongodump can reflect the state of the database at many different points in time.

Important

Use --forceTableScan with extreme caution and consideration.

--gzip

New in version 3.2.

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 or null>

New in version 3.2.

Writes the output to a single archive file or to the standard output (stdout).

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

To output the dump to the standard output stream in order to pipe to another process, run mongodump with the archive option but omit the filename.

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

--repair

Runs a repair option in addition to dumping the database. The repair option changes the behavior of mongodump to only write valid data and exclude data that may be in an invalid state as a result of an improper shutdown or mongod crash.

The --repair option uses aggressive data-recovery algorithms that may produce a large amount of duplication.

--repair is only available for use with mongod instances using the mmapv1 storage engine. You cannot run --repair with mongos or with mongod instances that use the wiredTiger storage engine. To repair data in a mongod instance using wiredTiger use mongod --repair.

--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. This file provides an effective point-in-time snapshot of the state of a mongod instance. To restore to a specific point-in-time backup, use the output created with this option in conjunction with mongorestore --oplogReplay.

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.

--oplog has no effect when running mongodump against a mongos instance to dump the entire contents of a sharded cluster. However, you can use --oplog to dump individual shards.

--oplog only works against nodes that maintain an oplog. This includes all members of a replica set, as well as master nodes in master/slave replication deployments.

--oplog does not dump the oplog collection.

--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

New in version 3.0.

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

--excludeCollectionsWithPrefix string

New in version 3.0.

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

New in version 3.4.

When specified, mongodump exports read-only views as collections. For each view, mongodump will produce a BSON file containing the documents in the view. If you mongorestore the produced BSON file, the view will be 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.

Examples

mongodump a Collection

The following operation creates a dump file that contains only the collection named collection in the database named test. In this case the database is running on the local interface on port 27017:

mongodump  --db test --collection collection

mongodump a Database Excluding Specified Collections

The following operation dumps all collections in the test database except for users and salaries:

mongodump  --db test --excludeCollection=users --excludeCollection=salaries

mongodump with Access Control

In the next example, mongodump creates a database dump located at /opt/backup/mongodump-2011-10-24, from a database running on port 37017 on the host mongodb1.example.net and authenticating using the username user and the password pass, as follows:

mongodump --host mongodb1.example.net --port 37017 --username user --password pass --out /opt/backup/mongodump-2011-10-24

Output to an Archive File

New in version 3.2.

To output the dump to an archive file, run mongodump with the --archive option and the archive filename. For example, the following operation creates a file test.20150715.archive that contains the dump of the test database.

mongodump --archive=test.20150715.archive --db test

Output an Archive to Standard Output

New in version 3.2.

To output the archive to the standard output stream in order to pipe to another process, run mongodump with the archive option but omit the filename:

mongodump --archive --db test --port 27017 | mongorestore --archive --port 27018

Note

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

Compress the Output

To compress the files in the output dump directory, run mongodump with the new --gzip option. For example, the following operation outputs compressed files into the default dump directory.

mongodump --gzip --db test

To compress the archive file output by mongodump, use the --gzip option in conjunction with the --archive option, specifying the name of the compressed file.

mongodump --archive=test.20150715.gz --gzip --db test
←   mongos.exe mongorestore  →