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Configuration File Options

The following page describes the configuration options available in MongoDB 4.4. For configuration file options for other versions of MongoDB, see the appropriate version of the MongoDB Manual.

Configuration File

You can configure mongod and mongos instances at startup using a configuration file. The configuration file contains settings that are equivalent to the mongod and mongos command-line options. See Configuration File Settings and Command-Line Options Mapping.

Using a configuration file makes managing mongod and mongos options easier, especially for large-scale deployments. You can also add comments to the configuration file to explain the server’s settings.

Default Configuration File

• On Linux, a default /etc/mongod.conf configuration file is included when using a package manager to install MongoDB.
• On Windows, a default <install directory>/bin/mongod.cfg configuration file is included during the installation.
• On macOS, a default /usr/local/etc/mongod.conf configuration file is included when installing from MongoDB’s official Homebrew tap.

File Format

MongoDB configuration files use the YAML format [1].

The following sample configuration file contains several mongod settings that you may adapt to your local configuration:

Note

YAML does not support tab characters for indentation: use spaces instead.

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systemLog:
   destination: file
   path: "/var/log/mongodb/mongod.log"
   logAppend: true
storage:
   journal:
      enabled: true
processManagement:
   fork: true
net:
   bindIp: 127.0.0.1
   port: 27017
setParameter:
   enableLocalhostAuthBypass: false
...

The Linux package init scripts included in the official MongoDB packages depend on specific values for systemLog.path, storage.dbPath, and processManagement.fork. If you modify these settings in the default configuration file, mongod may not start.

[1]	YAML is a superset of JSON.

Externally Sourced Values

New in version 4.2: MongoDB supports using expansion directives in configuration files to load externally sourced values. Expansion directives can load values for specific configuration file options or load the entire configuration file.

The following expansion directives are available:

Expansion Directive	Description
__rest	Allows users to specify a REST endpoint as the external source for configuration file options or the full configuration file. If the configuration file includes the __rest expansion, on Linux/macOS, the read access to the configuration file must be limited to the user running the mongod/mongos process only.
__exec	Allows users to specify a shell or terminal command as the external source for configuration file options or the full configuration file. If the configuration file includes the __exec expansion, on Linux/macOS, the write access to the configuration file must be limited to the user running the mongod/mongos process only.

For complete documentation, see Externally Sourced Configuration File Values.

Use the Configuration File

To configure mongod or mongos using a config file, specify the config file with the --config option or the -f option, as in the following examples:

For example, the following uses mongod --config <configuration file> mongos --config <configuration file>:

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mongod --config /etc/mongod.conf

mongos --config /etc/mongos.conf

You can also use the -f alias to specify the configuration file, as in the following:

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mongod -f /etc/mongod.conf

mongos -f /etc/mongos.conf

If you installed from a package and have started MongoDB using your system’s init script, you are already using a configuration file.

Expansion Directives and --configExpand

If you are using expansion directives in the configuration file, you must include the --configExpand option when starting the mongod or mongos. For example:

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mongod --config /etc/mongod.conf  --configExpand "rest,exec"
mongos --config /etc/mongos.conf  --configExpand "rest,exec"

If the configuration file includes an expansion directive and you start the mongod/mongos without specifying that directive in the --configExpand option, the mongod/mongos fails to start.

For complete documentation, see Externally Sourced Configuration File Values.

Core Options

systemLog Options

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systemLog:
   verbosity: <int>
   quiet: <boolean>
   traceAllExceptions: <boolean>
   syslogFacility: <string>
   path: <string>
   logAppend: <boolean>
   logRotate: <string>
   destination: <string>
   timeStampFormat: <string>
   component:
      accessControl:
         verbosity: <int>
      command:
         verbosity: <int>

      # COMMENT additional component verbosity settings omitted for brevity

systemLog.verbosity

Type: integer

Default: 0

The default log message verbosity level for components. The verbosity level determines the amount of Informational and Debug messages MongoDB outputs. [2]

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

To use a different verbosity level for a named component, use the component’s verbosity setting. For example, use the systemLog.component.accessControl.verbosity to set the verbosity level specifically for ACCESS components.

See the systemLog.component.<name>.verbosity settings for specific component verbosity settings.

For various ways to set the log verbosity level, see Configure Log Verbosity Levels.

[2]	Starting in version 4.2, MongoDB includes the Debug verbosity level (1-5) in the log messages. For example, if the verbosity level is 2, MongoDB logs D2. In previous versions, MongoDB log messages only specified D for Debug level.

systemLog.quiet

Type: boolean

Run mongos or mongod in a quiet mode that attempts to limit the amount of output.

systemLog.quiet is not recommended for production systems as it may make tracking problems during particular connections much more difficult.

systemLog.traceAllExceptions

Type: boolean

Print verbose information for debugging. Use for additional logging for support-related troubleshooting.

systemLog.syslogFacility

Type: string

Default: user

The facility level used when logging messages to syslog. The value you specify must be supported by your operating system’s implementation of syslog. To use this option, you must set systemLog.destination to syslog.

systemLog.path

Type: string

The path of the log file to which mongod or mongos should send all diagnostic logging information, rather than the standard output or the host’s syslog. MongoDB creates the log file at the specified path.

The Linux package init scripts do not expect systemLog.path to change from the defaults. If you use the Linux packages and change systemLog.path, you will have to use your own init scripts and disable the built-in scripts.

systemLog.logAppend

Type: boolean

Default: false

When true, mongos or mongod appends new entries to the end of the existing log file when the mongos or mongod instance restarts. Without this option, mongod will back up the existing log and create a new file.

systemLog.logRotate

Type: string

Default: rename

The behavior for the logRotate command. Specify either rename or reopen:

• rename renames the log file.

• reopen closes and reopens the log file following the typical Linux/Unix log rotate behavior. Use reopen when using the Linux/Unix logrotate utility to avoid log loss.

  If you specify reopen, you must also set systemLog.logAppend to true.

systemLog.destination

Type: string

The destination to which MongoDB sends all log output. Specify either file or syslog. If you specify file, you must also specify systemLog.path.

If you do not specify systemLog.destination, MongoDB sends all log output to standard output.

Warning

The syslog daemon generates timestamps when it logs a message, not when MongoDB issues the message. This can lead to misleading timestamps for log entries, especially when the system is under heavy load. We recommend using the file option for production systems to ensure accurate timestamps.

systemLog.timeStampFormat

Type: string

Default: iso8601-local

The time format for timestamps in log messages. Specify one of the following values:

Value	Description
iso8601-utc	Displays timestamps in Coordinated Universal Time (UTC) in the ISO-8601 format. For example, for New York at the start of the Epoch: 1970-01-01T00:00:00.000Z
iso8601-local	Displays timestamps in local time in the ISO-8601 format. For example, for New York at the start of the Epoch: 1969-12-31T19:00:00.000-05:00

Note

Starting in MongoDB 4.4, systemLog.timeStampFormat no longer supports ctime. An example of ctime formatted date is: Wed Dec 31 18:17:54.811.

systemLog.component Options

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systemLog:
   component:
      accessControl:
         verbosity: <int>
      command:
         verbosity: <int>

      # COMMENT some component verbosity settings omitted for brevity

      replication:
         verbosity: <int>
         election:
            verbosity: <int>
         heartbeats:
            verbosity: <int>
         initialSync:
            verbosity: <int>
         rollback:
            verbosity: <int>
      storage:
         verbosity: <int>
         journal:
            verbosity: <int>
         recovery:
            verbosity: <int>
      write:
         verbosity: <int>

Note

Starting in version 4.2, MongoDB includes the Debug verbosity level (1-5) in the log messages. For example, if the verbosity level is 2, MongoDB logs D2. In previous versions, MongoDB log messages only specified D for Debug level.

systemLog.component.accessControl.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to access control. See ACCESS components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.command.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to commands. See COMMAND components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.control.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to control operations. See CONTROL components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.ftdc.verbosity

Type: integer

Default: 0

New in version 3.2.

The log message verbosity level for components related to diagnostic data collection operations. See FTDC components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.geo.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to geospatial parsing operations. See GEO components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.index.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to indexing operations. See INDEX components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.network.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to networking operations. See NETWORK components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.query.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to query operations. See QUERY components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.replication.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to replication. See REPL components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.replication.election.verbosity

Type: integer

Default: 0

New in version 4.2.

The log message verbosity level for components related to election. See ELECTION components.

If systemLog.component.replication.election.verbosity is unset, systemLog.component.replication.verbosity level also applies to election components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.replication.heartbeats.verbosity

Type: integer

Default: 0

New in version 3.6.

The log message verbosity level for components related to heartbeats. See REPL_HB components.

If systemLog.component.replication.heartbeats.verbosity is unset, systemLog.component.replication.verbosity level also applies to heartbeats components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.replication.initialSync.verbosity

Type: integer

Default: 0

New in version 4.2.

The log message verbosity level for components related to initialSync. See INITSYNC components.

If systemLog.component.replication.initialSync.verbosity is unset, systemLog.component.replication.verbosity level also applies to initialSync components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.replication.rollback.verbosity

Type: integer

Default: 0

New in version 3.6.

The log message verbosity level for components related to rollback. See ROLLBACK components.

If systemLog.component.replication.rollback.verbosity is unset, systemLog.component.replication.verbosity level also applies to rollback components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.sharding.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to sharding. See SHARDING components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.storage.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to storage. See STORAGE components.

If systemLog.component.storage.journal.verbosity is unset, systemLog.component.storage.verbosity level also applies to journaling components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.storage.journal.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to journaling. See JOURNAL components.

If systemLog.component.storage.journal.verbosity is unset, the journaling components have the same verbosity level as the parent storage components: i.e. either the systemLog.component.storage.verbosity level if set or the default verbosity level.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.storage.recovery.verbosity

Type: integer

Default: 0

New in version 4.0.

The log message verbosity level for components related to recovery. See RECOVERY components.

If systemLog.component.storage.recovery.verbosity is unset, systemLog.component.storage.verbosity level also applies to recovery components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.transaction.verbosity

Type: integer

Default: 0

New in version 4.0.2.

The log message verbosity level for components related to transaction. See TXN components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

systemLog.component.write.verbosity

Type: integer

Default: 0

The log message verbosity level for components related to write operations. See WRITE components.

The verbosity level can range from 0 to 5:

• 0 is the MongoDB’s default log verbosity level, to include Informational messages.
• 1 to 5 increases the verbosity level to include Debug messages.

processManagement Options

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processManagement:
   fork: <boolean>
   pidFilePath: <string>
   timeZoneInfo: <string>

processManagement.fork

Type: boolean

Default: false

Enable a daemon mode that runs the mongos or mongod process in the background. By default mongos or mongod does not run as a daemon: typically you will run mongos or mongod as a daemon, either by using processManagement.fork or by using a controlling process that handles the daemonization process (e.g. as with upstart and systemd).

The processManagement.fork option is not supported on Windows.

The Linux package init scripts do not expect processManagement.fork to change from the defaults. If you use the Linux packages and change processManagement.fork, you will have to use your own init scripts and disable the built-in scripts.

processManagement.pidFilePath

Type: string

Specifies a file location to store the process ID (PID) of the mongos or mongod process. The user running the mongod or mongos process must be able to write to this path. If the processManagement.pidFilePath option is not specified, the process does not create a PID file. This option is generally only useful in combination with the processManagement.fork setting.

Linux

On Linux, PID file management is generally the responsibility of your distro’s init system: usually a service file in the /etc/init.d directory, or a systemd unit file registered with systemctl. Only use the processManagement.pidFilePath option if you are not using one of these init systems. For more information, please see the respective Installation Guide for your operating system.

macOS

On macOS, PID file management is generally handled by brew. Only use the processManagement.pidFilePath option if you are not using brew on your macOS system. For more information, please see the respective Installation Guide for your operating system.

processManagement.timeZoneInfo

Type: string

The full path from which to load the time zone database. If this option is not provided, then MongoDB will use its built-in time zone database.

The configuration file included with Linux and macOS packages sets the time zone database path to /usr/share/zoneinfo by default.

The built-in time zone database is a copy of the Olson/IANA time zone database. It is updated along with MongoDB releases, but the release cycle of the time zone database differs from the release cycle of MongoDB. A copy of the most recent release of the time zone database can be downloaded from https://downloads.mongodb.org/olson_tz_db/timezonedb-latest.zip.

cloud Options

New in version 4.0.

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cloud:
   monitoring:
      free:
         state: <string>
         tags: <string>

cloud.monitoring.free.state

Type: string

New in version 4.0: Available for MongoDB Community Edition.

Enables or disables free MongoDB Cloud monitoring. cloud.monitoring.free.state accepts the following values:

runtime	Default. You can enable or disable free monitoring during runtime. To enable or disable free monitoring during runtime, see db.enableFreeMonitoring() and db.disableFreeMonitoring(). To enable or disable free monitoring during runtime when running with access control, users must have required privileges. See db.enableFreeMonitoring() and db.disableFreeMonitoring() for details.
on	Enables free monitoring at startup; i.e. registers for free monitoring. When enabled at startup, you cannot disable free monitoring during runtime.
off	Disables free monitoring at startup, regardless of whether you have previously registered for free monitoring. When disabled at startup, you cannot enable free monitoring during runtime.

Once enabled, the free monitoring state remains enabled until explicitly disabled. That is, you do not need to re-enable each time you start the server.

For the corresponding command-line option, see --enableFreeMonitoring.

cloud.monitoring.free.tags

Type: string

New in version 4.0: Available for MongoDB Community Edition.

Optional tag to describe environment context. The tag can be sent as part of the free MongoDB Cloud monitoring registration at start up.

For the corresponding command-line option, see --freeMonitoringTag.

net Options

Changed in version 4.2: MongoDB 4.2 deprecates ssl options in favor of tls options with identical functionality.

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net:
   port: <int>
   bindIp: <string>
   bindIpAll: <boolean>
   maxIncomingConnections: <int>
   wireObjectCheck: <boolean>
   ipv6: <boolean>
   unixDomainSocket:
      enabled: <boolean>
      pathPrefix: <string>
      filePermissions: <int>
   tls:
      certificateSelector: <string>
      clusterCertificateSelector: <string>
      mode: <string>
      certificateKeyFile: <string>
      certificateKeyFilePassword: <string>
      clusterFile: <string>
      clusterPassword: <string>
      CAFile: <string>
      clusterCAFile: <string>
      CRLFile: <string>
      allowConnectionsWithoutCertificates: <boolean>
      allowInvalidCertificates: <boolean>
      allowInvalidHostnames: <boolean>
      disabledProtocols: <string>
      FIPSMode: <boolean>
   compression:
      compressors: <string>
   serviceExecutor: <string>

net.port

Type: integer

Default:

• 27017 for mongod (if not a shard member or a config server member) or mongos instance
• 27018 if mongod is a shard member
• 27019 if mongod is a config server member

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

net.bindIp

Type: string

Default: localhost

Note

Starting in MongoDB 3.6, mongos or mongod bind to localhost by default. See Default Bind to Localhost.

The hostnames and/or IP addresses and/or full Unix domain socket paths on which mongos or mongod should listen for client connections. You may attach mongos or mongod to any interface. To bind to multiple addresses, enter a list of comma-separated values.

Example

localhost,/tmp/mongod.sock

You can specify both IPv4 and IPv6 addresses, or hostnames that resolve to an IPv4 or IPv6 address.

Example

localhost, 2001:0DB8:e132:ba26:0d5c:2774:e7f9:d513

Note

If specifying an IPv6 address or a hostname that resolves to an IPv6 address to net.bindIp, you must start mongos or mongod with net.ipv6 : true to enable IPv6 support. Specifying an IPv6 address to net.bindIp does not enable IPv6 support.

If specifying a link-local IPv6 address (fe80::/10), you must append the zone index to that address (i.e. fe80::<address>%<adapter-name>).

Example

localhost,fe80::a00:27ff:fee0:1fcf%enp0s3

Tip

When possible, use a logical DNS hostname instead of an ip address, particularly when configuring replica set members or sharded cluster members. The use of logical DNS hostnames avoids configuration changes due to ip address changes.

Warning

Before binding to a non-localhost (e.g. publicly accessible) IP address, ensure you have secured your cluster from unauthorized access. For a complete list of security recommendations, see Security Checklist. At minimum, consider enabling authentication and hardening network infrastructure.

For more information about IP Binding, refer to the IP Binding documentation.

To bind to all IPv4 addresses, enter 0.0.0.0.

To bind to all IPv4 and IPv6 addresses, enter ::,0.0.0.0 or starting in MongoDB 4.2, an asterisk "*" (enclose the asterisk in quotes to distinguish from YAML alias nodes). Alternatively, use the net.bindIpAll setting.

Note

• net.bindIp and net.bindIpAll are mutually exclusive. That is, you can specify one or the other, but not both.
• The command-line option --bind_ip overrides the configuration file setting net.bindIp.

net.bindIpAll

Type: boolean

Default: false

New in version 3.6.

If true, the mongos or mongod instance binds to all IPv4 addresses (i.e. 0.0.0.0). If mongos or mongod starts with net.ipv6 : true, net.bindIpAll also binds to all IPv6 addresses (i.e. ::).

mongos or mongod only supports IPv6 if started with net.ipv6 : true. Specifying net.bindIpAll alone does not enable IPv6 support.

Warning

Before binding to a non-localhost (e.g. publicly accessible) IP address, ensure you have secured your cluster from unauthorized access. For a complete list of security recommendations, see Security Checklist. At minimum, consider enabling authentication and hardening network infrastructure.

For more information about IP Binding, refer to the IP Binding documentation.

Alternatively, set net.bindIp to ::,0.0.0.0 or, starting in MongoDB 4.2, to an asterisk "*" (enclose the asterisk in quotes to distinguish from YAML alias nodes) to bind to all IP addresses.

Note

net.bindIp and net.bindIpAll are mutually exclusive. Specifying both options causes mongos or mongod to throw an error and terminate.

net.maxIncomingConnections

Type: integer

Default: 65536

The maximum number of simultaneous connections that mongos or mongod will accept. This setting has no effect if it is higher than your operating system’s configured maximum connection tracking threshold.

Do not assign too low of a value to this option, or you will encounter errors during normal application operation.

This is particularly useful for a mongos if you have a client that creates multiple connections and allows them to timeout rather than closing them.

In this case, set maxIncomingConnections to a value slightly higher than the maximum number of connections that the client creates, or the maximum size of the connection pool.

This setting prevents the mongos from causing connection spikes on the individual shards. Spikes like these may disrupt the operation and memory allocation of the sharded cluster.

net.wireObjectCheck

Type: boolean

Default: true

When true, the mongod or mongos instance validates all requests from clients upon receipt to prevent clients from inserting malformed or invalid BSON into a MongoDB database.

For objects with a high degree of sub-document nesting, net.wireObjectCheck can have a small impact on performance.

net.ipv6

Type: boolean

Default: false

Set net.ipv6 to true to enable IPv6 support. mongos/mongod disables IPv6 support by default.

Setting net.ipv6 does not direct the mongos/mongod to listen on any local IPv6 addresses or interfaces. To configure the mongos/mongod to listen on an IPv6 interface, you must either:

• Configure net.bindIp with one or more IPv6 addresses or hostnames that resolve to IPv6 addresses, or
• Set net.bindIpAll to true.

net.unixDomainSocket Options

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net:
   unixDomainSocket:
      enabled: <boolean>
      pathPrefix: <string>
      filePermissions: <int>

net.unixDomainSocket.enabled

Type: boolean

Default: true

Enable or disable listening on the UNIX domain socket. net.unixDomainSocket.enabled applies only to Unix-based systems.

When net.unixDomainSocket.enabled is true, mongos or mongod listens on the UNIX socket.

The mongos or mongod process always listens on the UNIX socket unless one of the following is true:

• net.unixDomainSocket.enabled is false
• --nounixsocket is set. The command line option takes precedence over the configuration file setting.
• net.bindIp is not set
• net.bindIp does not specify localhost or its associated IP address

mongos or mongod installed from official .deb and .rpm packages have the bind_ip configuration set to 127.0.0.1 by default.

net.unixDomainSocket.pathPrefix

Type: string

Default: /tmp

The path for the UNIX socket. net.unixDomainSocket.pathPrefix applies only to Unix-based systems.

If this option has no value, the mongos or mongod process creates a socket with /tmp as a prefix. MongoDB creates and listens on a UNIX socket unless one of the following is true:

• net.unixDomainSocket.enabled is false
• --nounixsocket is set
• net.bindIp is not set
• net.bindIp does not specify localhost or its associated IP address

net.unixDomainSocket.filePermissions

Type: int

Default: 0700

Sets the permission for the UNIX domain socket file.

net.unixDomainSocket.filePermissions applies only to Unix-based systems.

net.http Options

Changed in version 3.6: MongoDB 3.6 removes the deprecated net.http options. The options have been deprecated since version 3.2.

net.tls Options

New in version 4.2: The tls options provide identical functionality as the previous ssl options.

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net:
   tls:
      mode: <string>
      certificateKeyFile: <string>
      certificateKeyFilePassword: <string>
      certificateSelector: <string>
      clusterCertificateSelector: <string>
      clusterFile: <string>
      clusterPassword: <string>
      CAFile: <string>
      clusterCAFile: <string>
      CRLFile: <string>
      allowConnectionsWithoutCertificates: <boolean>
      allowInvalidCertificates: <boolean>
      allowInvalidHostnames: <boolean>
      disabledProtocols: <string>
      FIPSMode: <boolean>

net.tls.mode

Type: string

New in version 4.2.

Enables TLS used for all network connections. The argument to the net.tls.mode setting can be one of the following:

Value	Description
disabled	The server does not use TLS.
allowTLS	Connections between servers do not use TLS. For incoming connections, the server accepts both TLS and non-TLS.
preferTLS	Connections between servers use TLS. For incoming connections, the server accepts both TLS and non-TLS.
requireTLS	The server uses and accepts only TLS encrypted connections.

If --tlsCAFile or tls.CAFile is not specified and you are not using x.509 authentication, the system-wide CA certificate store will be used when connecting to an TLS-enabled server.

If using x.509 authentication, --tlsCAFile or tls.CAFile must be specified unless using --tlsCertificateSelector.

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

net.tls.certificateKeyFile

Type: string

New in version 4.2: The .pem file that contains both the TLS certificate and key.

Starting with MongoDB 4.0 on macOS or Windows, you can use the net.tls.certificateSelector setting to specify a certificate from the operating system’s secure certificate store instead of a PEM key file. certificateKeyFile and net.tls.certificateSelector are mutually exclusive. You can only specify one.

• On Linux/BSD, you must specify net.tls.certificateKeyFile when TLS is enabled.

• On Windows or macOS, you must specify either net.tls.certificateKeyFile or net.tls.certificateSelector when TLS is enabled.

  Important

  For Windows only, MongoDB 4.0 and later do not support encrypted PEM files. The mongod fails to start if it encounters an encrypted PEM file. To securely store and access a certificate for use with TLS on Windows, use net.tls.certificateSelector.

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

net.tls.certificateKeyFilePassword

Type: string

New in version 4.2: The password to de-crypt the certificate-key file (i.e. certificateKeyFile). Use the net.tls.certificateKeyPassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod will redact the password from all logging and reporting output.

Starting in MongoDB 4.0:

• On Linux/BSD, if the private key in the PEM file is encrypted and you do not specify the net.tls.certificateKeyFukePassword option, MongoDB will prompt for a passphrase. See TLS/SSL Certificate Passphrase.
• On macOS, if the private key in the PEM file is encrypted, you must explicitly specify the net.tls.certificateKeyFilePassword option. Alternatively, you can use a certificate from the secure system store (see net.tls.certificateSelector) instead of a PEM key file or use an unencrypted PEM file.
• On Windows, MongoDB does not support encrypted certificates. The mongod fails if it encounters an encrypted PEM file. Use net.tls.certificateSelector instead.

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

net.tls.certificateSelector

Type: string

New in version 4.2: Available on Windows and macOS as an alternative to net.tls.certificateKeyFile. In MongoDB 4.0, see net.ssl.certificateSelector.

Specifies a certificate property in order to select a matching certificate from the operating system’s certificate store to use for TLS/SSL.

net.tls.certificateKeyFile and net.tls.certificateSelector options are mutually exclusive. You can only specify one.

net.tls.certificateSelector accepts an argument of the format <property>=<value> where the property can be one of the following:

Property	Value type	Description
subject	ASCII string	Subject name or common name on certificate
thumbprint	hex string	A sequence of bytes, expressed as hexadecimal, used to identify a public key by its SHA-1 digest. The thumbprint is sometimes referred to as a fingerprint.

When using the system SSL certificate store, OCSP (Online Certificate Status Protocol) is used to validate the revocation status of certificates.

The mongod searches the operating system’s secure certificate store for the CA certificates required to validate the full certificate chain of the specified TLS certificate. Specifically, the secure certificate store must contain the root CA and any intermediate CA certificates required to build the full certificate chain to the TLS certificate. Do not use net.tls.CAFile or net.tls.clusterFile to specify the root and intermediate CA certificate

For example, if the TLS certificate was signed with a single root CA certificate, the secure certificate store must contain that root CA certificate. If the TLS certificate was signed with an intermediate CA certificate, the secure certificate store must contain the intermedia CA certificate and the root CA certificate.

net.tls.clusterCertificateSelector

Type: string

New in version 4.2: Available on Windows and macOS as an alternative to net.tls.clusterFile.

Specifies a certificate property to select a matching certificate from the operating system’s secure certificate store to use for internal x.509 membership authentication.

net.tls.clusterFile and net.tls.clusterCertificateSelector options are mutually exclusive. You can only specify one.

net.tls.clusterCertificateSelector accepts an argument of the format <property>=<value> where the property can be one of the following:

Property	Value type	Description
subject	ASCII string	Subject name or common name on certificate
thumbprint	hex string	A sequence of bytes, expressed as hexadecimal, used to identify a public key by its SHA-1 digest. The thumbprint is sometimes referred to as a fingerprint.

The mongod searches the operating system’s secure certificate store for the CA certificates required to validate the full certificate chain of the specified cluster certificate. Specifically, the secure certificate store must contain the root CA and any intermediate CA certificates required to build the full certificate chain to the cluster certificate. Do not use net.tls.CAFile or net.tls.clusterCAFile to specify the root and intermediate CA certificate.

For example, if the cluster certificate was signed with a single root CA certificate, the secure certificate store must contain that root CA certificate. If the cluster certificate was signed with an intermediate CA certificate, the secure certificate store must contain the intermediate CA certificate and the root CA certificate.

Changed in version 4.4: mongod / mongos logs a warning on connection if the presented x.509 certificate expires within 30 days of the mongod/mongos host system time. See x.509 Certificates Nearing Expiry Trigger Warnings for more information.

net.tls.clusterFile

Type: string

New in version 4.2: The .pem file that contains the x.509 certificate-key file for membership authentication for the cluster or replica set.

Starting with MongoDB 4.0 on macOS or Windows, you can use the net.tls.clusterCertificateSelector option to specify a certificate from the operating system’s secure certificate store instead of a PEM key file. net.tls.clusterFile and net.tls.clusterCertificateSelector options are mutually exclusive. You can only specify one.

If net.tls.clusterFile does not specify the .pem file for internal cluster authentication or the alternative net.tls.clusterCertificateSelector, the cluster uses the .pem file specified in the certificateKeyFile setting or the certificate returned by the net.tls.certificateSelector.

If using x.509 authentication, --tlsCAFile or tls.CAFile must be specified unless using --tlsCertificateSelector.

Changed in version 4.4: mongod / mongos logs a warning on connection if the presented x.509 certificate expires within 30 days of the mongod/mongos host system time. See x.509 Certificates Nearing Expiry Trigger Warnings for more information.

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

Important

For Windows only, MongoDB 4.0 and later do not support encrypted PEM files. The mongod fails to start if it encounters an encrypted PEM file. To securely store and access a certificate for use with membership authentication on Windows, use net.tls.clusterCertificateSelector.

net.tls.clusterPassword

Type: string

New in version 4.2: The password to de-crypt the x.509 certificate-key file specified with --sslClusterFile. Use the net.tls.clusterPassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod will redact the password from all logging and reporting output.

Starting in MongoDB 4.0:

• On Linux/BSD, if the private key in the x.509 file is encrypted and you do not specify the net.tls.clusterPassword option, MongoDB will prompt for a passphrase. See TLS/SSL Certificate Passphrase.
• On macOS, if the private key in the x.509 file is encrypted, you must explicitly specify the net.tls.clusterPassword option. Alternatively, you can either use a certificate from the secure system store (see net.tls.clusterCertificateSelector) instead of a cluster PEM file or use an unencrypted PEM file.
• On Windows, MongoDB does not support encrypted certificates. The mongod fails if it encounters an encrypted PEM file. Use net.tls.clusterCertificateSelector.

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

net.tls.CAFile

Type: string

New in version 4.2: 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.

Windows/macOS Only

If using net.tls.certificateSelector and/or net.tls.clusterCertificateSelector, do not use net.tls.CAFile to specify the root and intermediate CA certificates. Store all CA certificates required to validate the full trust chain of the net.tls.certificateSelector and/or net.tls.clusterCertificateSelector certificates in the secure certificate store.

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

net.tls.clusterCAFile

Type: string

New in version 4.2: The .pem file that contains the root certificate chain from the Certificate Authority used to validate the certificate presented by a client establishing a connection. Specify the file name of the .pem file using relative or absolute paths. net.tls.clusterCAFile requires that net.tls.CAFile is set.

If net.tls.clusterCAFile does not specify the .pem file for validating the certificate from a client establishing a connection, the cluster uses the .pem file specified in the net.tls.CAFile option.

net.tls.clusterCAFile lets you use separate Certificate Authorities to verify the client to server and server to client portions of the TLS handshake.

Starting in 4.0, on macOS or Windows, you can use a certificate from the operating system’s secure store instead of a PEM key file. See net.tls.clusterCertificateSelector. When using the secure store, you do not need to, but can, also specify the net.tls.clusterCAFile.

Windows/macOS Only

If using net.tls.certificateSelector and/or net.tls.clusterCertificateSelector, do not use net.tls.clusterCAFile to specify the root and intermediate CA certificates. Store all CA certificates required to validate the full trust chain of the net.tls.certificateSelector and/or net.tls.clusterCertificateSelector certificates in the secure certificate store.

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

net.tls.CRLFile

Type: string

New in version 4.2: In MongoDB 4.0 and earlier, see net.ssl.CRLFile.

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

Note

• Starting in MongoDB 4.0, you cannot specify net.tls.CRLFile on macOS. Instead, you can use the system SSL certificate store, which uses OCSP (Online Certificate Status Protocol) to validate the revocation status of certificates. See net.ssl.certificateSelector in MongoDB 4.0 and net.tls.certificateSelector in MongoDB 4.2+ to use the system SSL certificate store.
• Starting in version 4.4, to check for certificate revocation, MongoDB enables the use of OCSP (Online Certificate Status Protocol) by default as an alternative to specifying a CRL file or using the system SSL certificate store.

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

net.tls.allowConnectionsWithoutCertificates

Type: boolean

New in version 4.2.

For clients that do not present certificates, mongos or mongod bypasses TLS/SSL certificate validation when establishing the connection.

For clients that present a certificate, however, mongos or mongod performs certificate validation using the root certificate chain specified by CAFile and reject clients with invalid certificates.

Use the net.tls.allowConnectionsWithoutCertificates option if you have a mixed deployment that includes clients that do not or cannot present certificates to the mongos or mongod.

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

net.tls.allowInvalidCertificates

Type: boolean

New in version 4.2.

Enable or disable the validation checks for TLS certificates on other servers in the cluster and allows the use of invalid certificates to connect.

Note

If you specify --tlsAllowInvalidCertificates or tls.allowInvalidCertificates: true when using x.509 authentication, an invalid certificate is only sufficient to establish a TLS connection but is insufficient for authentication.

When using the net.tls.allowInvalidCertificates setting, MongoDB logs a warning regarding the use of the invalid certificate.

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

net.tls.allowInvalidHostnames

Type: boolean

Default: false

When net.tls.allowInvalidHostnames is true, MongoDB disables the validation of the hostnames in TLS certificates, allowing mongod to connect to MongoDB instances if the hostname their certificates do not match the specified hostname.

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

net.tls.disabledProtocols

Type: string

New in version 4.2.

Prevents a MongoDB server running with TLS from accepting incoming connections that use a specific protocol or protocols. To specify multiple protocols, use a comma separated list of protocols.

net.tls.disabledProtocols recognizes the following protocols: TLS1_0, TLS1_1, TLS1_2, and starting in version 4.0.4 (and 3.6.9), TLS1_3.

• On macOS, you cannot disable TLS1_1 and leave both TLS1_0 and TLS1_2 enabled. You must disable at least one of the other two, for example, TLS1_0,TLS1_1.
• To list multiple protocols, specify as a comma separated list of protocols. For example TLS1_0,TLS1_1.
• Specifying an unrecognized protocol will prevent the server from starting.
• The specified disabled protocols overrides any default disabled protocols.

Starting in version 4.0, MongoDB disables the use of TLS 1.0 if TLS 1.1+ is available on the system. To enable the disabled TLS 1.0, specify none to net.tls.disabledProtocols. See Disable TLS 1.0.

Members of replica sets and sharded clusters must speak at least one protocol in common.

See also

Disallow Protocols

net.tls.FIPSMode

Type: boolean

New in version 4.2.

Enable or disable the use of the FIPS mode of the TLS library for the mongos or mongod. Your system must have a FIPS compliant library to use the net.tls.FIPSMode option.

Note

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

net.ssl Options

Important

All SSL options are deprecated since 4.2. Use the TLS counterparts instead, as they have identical functionality to the SSL options. The SSL protocol is deprecated and MongoDB supports TLS 1.0 and later.

copy

net:
   ssl:                            # deprecated since 4.2
      sslOnNormalPorts: <boolean>  # deprecated since 2.6
      mode: <string>
      PEMKeyFile: <string>
      PEMKeyPassword: <string>
      certificateSelector: <string>
      clusterCertificateSelector: <string>
      clusterFile: <string>
      clusterPassword: <string>
      CAFile: <string>
      clusterCAFile: <string>
      CRLFile: <string>
      allowConnectionsWithoutCertificates: <boolean>
      allowInvalidCertificates: <boolean>
      allowInvalidHostnames: <boolean>
      disabledProtocols: <string>
      FIPSMode: <boolean>

net.ssl.sslOnNormalPorts

Type: boolean

Deprecated since version 2.6: Use net.tls.mode: requireTLS instead.

Enable or disable TLS/SSL for mongos or mongod.

With net.ssl.sslOnNormalPorts, a mongos or mongod requires TLS/SSL encryption for all connections on the default MongoDB port, or the port specified by net.port. By default, net.ssl.sslOnNormalPorts is disabled.

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

net.ssl.mode

Type: string

Deprecated since version 4.2: Use net.tls.mode instead.

Enables TLS/SSL or mixed TLS/SSL used for all network connections. The argument to the net.ssl.mode setting can be one of the following:

Value	Description
disabled	The server does not use TLS/SSL.
allowSSL	Connections between servers do not use TLS/SSL. For incoming connections, the server accepts both TLS/SSL and non-TLS/non-SSL.
preferSSL	Connections between servers use TLS/SSL. For incoming connections, the server accepts both TLS/SSL and non-TLS/non-SSL.
requireSSL	The server uses and accepts only TLS/SSL encrypted connections.

Starting in version 3.4, if --tlsCAFile/net.tls.CAFile (or their aliases --sslCAFile/net.ssl.CAFile) is not specified and you are not using x.509 authentication, the system-wide CA certificate store will be used when connecting to an TLS/SSL-enabled server.

To use x.509 authentication, --tlsCAFile or net.tls.CAFile must be specified unless using --tlsCertificateSelector or --net.tls.certificateSelector. Or if using the ssl aliases, --sslCAFile or net.ssl.CAFile must be specified unless using --sslCertificateSelector or net.ssl.certificateSelector.

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

net.ssl.PEMKeyFile

Type: string

Deprecated since version 4.2: Use net.tls.certificateKeyFile instead.

The .pem file that contains both the TLS/SSL certificate and key.

Starting with MongoDB 4.0 on macOS or Windows, you can use the net.ssl.certificateSelector setting to specify a certificate from the operating system’s secure certificate store instead of a PEM key file. PEMKeyFile and net.ssl.certificateSelector are mutually exclusive. You can only specify one.

• On Linux/BSD, you must specify net.ssl.PEMKeyFile when TLS/SSL is enabled.

• On Windows or macOS, you must specify either net.ssl.PEMKeyFile or net.ssl.certificateSelector when TLS/SSL is enabled.

  Important

  For Windows only, MongoDB 4.0 and later do not support encrypted PEM files. The mongod fails to start if it encounters an encrypted PEM file. To securely store and access a certificate for use with TLS/SSL on Windows, use net.ssl.certificateSelector.

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

net.ssl.PEMKeyPassword

Type: string

Deprecated since version 4.2: Use net.tls.certificateKeyFilePassword instead.

The password to de-crypt the certificate-key file (i.e. PEMKeyFile). Use the net.ssl.PEMKeyPassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod will redact the password from all logging and reporting output.

Starting in MongoDB 4.0:

• On Linux/BSD, if the private key in the PEM file is encrypted and you do not specify the net.ssl.PEMKeyPassword option, MongoDB will prompt for a passphrase. See TLS/SSL Certificate Passphrase.
• On macOS, if the private key in the PEM file is encrypted, you must explicitly specify the net.ssl.PEMKeyPassword option. Alternatively, you can use a certificate from the secure system store (see net.ssl.certificateSelector) instead of a PEM key file or use an unencrypted PEM file.
• On Windows, MongoDB does not support encrypted certificates. The mongod fails if it encounters an encrypted PEM file. Use net.ssl.certificateSelector instead.

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

net.ssl.certificateSelector

Type: string

Deprecated since version 4.2: Use net.tls.certificateSelector instead.

New in version 4.0: Available on Windows and macOS as an alternative to net.ssl.PEMKeyFile.

Specifies a certificate property in order to select a matching certificate from the operating system’s certificate store to use for TLS/SSL.

net.ssl.PEMKeyFile and net.ssl.certificateSelector options are mutually exclusive. You can only specify one.

net.ssl.certificateSelector accepts an argument of the format <property>=<value> where the property can be one of the following:

Property	Value type	Description
subject	ASCII string	Subject name or common name on certificate
thumbprint	hex string	A sequence of bytes, expressed as hexadecimal, used to identify a public key by its SHA-1 digest. The thumbprint is sometimes referred to as a fingerprint.

When using the system SSL certificate store, OCSP (Online Certificate Status Protocol) is used to validate the revocation status of certificates.

The mongod searches the operating system’s secure certificate store for the CA certificates required to validate the full certificate chain of the specified TLS/SSL certificate. Specifically, the secure certificate store must contain the root CA and any intermediate CA certificates required to build the full certificate chain to the TLS/SSL certificate. Do not use net.ssl.CAFile or net.ssl.clusterFile to specify the root and intermediate CA certificate

For example, if the TLS/SSL certificate was signed with a single root CA certificate, the secure certificate store must contain that root CA certificate. If the TLS/SSL certificate was signed with an intermediate CA certificate, the secure certificate store must contain the intermedia CA certificate and the root CA certificate.

net.ssl.clusterCertificateSelector

Type: string

Deprecated since version 4.2: Use net.tls.clusterCertificateSelector instead.

New in version 4.0: Available on Windows and macOS as an alternative to net.ssl.clusterFile.

Specifies a certificate property to select a matching certificate from the operating system’s secure certificate store to use for internal x.509 membership authentication.

net.ssl.clusterFile and net.ssl.clusterCertificateSelector options are mutually exclusive. You can only specify one.

net.ssl.clusterCertificateSelector accepts an argument of the format <property>=<value> where the property can be one of the following:

Property	Value type	Description
subject	ASCII string	Subject name or common name on certificate
thumbprint	hex string	A sequence of bytes, expressed as hexadecimal, used to identify a public key by its SHA-1 digest. The thumbprint is sometimes referred to as a fingerprint.

The mongod searches the operating system’s secure certificate store for the CA certificates required to validate the full certificate chain of the specified cluster certificate. Specifically, the secure certificate store must contain the root CA and any intermediate CA certificates required to build the full certificate chain to the cluster certificate. Do not use net.ssl.CAFile or net.ssl.clusterFile to specify the root and intermediate CA certificate.

For example, if the cluster certificate was signed with a single root CA certificate, the secure certificate store must contain that root CA certificate. If the cluster certificate was signed with an intermediate CA certificate, the secure certificate store must contain the intermedia CA certificate and the root CA certificate.

net.ssl.clusterFile

Type: string

Deprecated since version 4.2: Use net.tls.clusterFile instead.

The .pem file that contains the x.509 certificate-key file for membership authentication for the cluster or replica set.

Starting with MongoDB 4.0 on macOS or Windows, you can use the net.ssl.clusterCertificateSelector option to specify a certificate from the operating system’s secure certificate store instead of a PEM key file. net.ssl.clusterFile and net.ssl.clusterCertificateSelector options are mutually exclusive. You can only specify one.

If net.ssl.clusterFile does not specify the .pem file for internal cluster authentication or the alternative net.ssl.clusterCertificateSelector, the cluster uses the .pem file specified in the PEMKeyFile setting or the certificate returned by the net.ssl.certificateSelector.

To use x.509 authentication, --tlsCAFile or net.tls.CAFile must be specified unless using --tlsCertificateSelector or --net.tls.certificateSelector. Or if using the ssl aliases, --sslCAFile or net.ssl.CAFile must be specified unless using --sslCertificateSelector or net.ssl.certificateSelector.

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

Important

For Windows only, MongoDB 4.0 and later do not support encrypted PEM files. The mongod fails to start if it encounters an encrypted PEM file. To securely store and access a certificate for use with membership authentication on Windows, use net.ssl.clusterCertificateSelector.

net.ssl.clusterPassword

Type: string

Deprecated since version 4.2: Use net.tls.clusterPassword instead.

The password to de-crypt the x.509 certificate-key file specified with --sslClusterFile. Use the net.ssl.clusterPassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod will redact the password from all logging and reporting output.

Starting in MongoDB 4.0:

• On Linux/BSD, if the private key in the x.509 file is encrypted and you do not specify the net.ssl.clusterPassword option, MongoDB will prompt for a passphrase. See TLS/SSL Certificate Passphrase.
• On macOS, if the private key in the x.509 file is encrypted, you must explicitly specify the net.ssl.clusterPassword option. Alternatively, you can either use a certificate from the secure system store (see net.ssl.clusterCertificateSelector) instead of a cluster PEM file or use an unencrypted PEM file.
• On Windows, MongoDB does not support encrypted certificates. The mongod fails if it encounters an encrypted PEM file. Use net.ssl.clusterCertificateSelector.

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

net.ssl.CAFile

Type: string

Deprecated since version 4.2: Use net.tls.CAFile instead.

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.

Windows/macOS Only

If using net.ssl.certificateSelector and/or net.ssl.clusterCertificateSelector, do not use net.ssl.CAFile to specify the root and intermediate CA certificates. Store all CA certificates required to validate the full trust chain of the net.ssl.certificateSelector and/or net.ssl.clusterCertificateSelector certificates in the secure certificate store.

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

net.ssl.clusterCAFile

Type: string

Deprecated since version 4.2: Use net.tls.clusterCAFile instead.

The .pem file that contains the root certificate chain from the Certificate Authority used to validate the certificate presented by a client establishing a connection. Specify the file name of the .pem file using relative or absolute paths. net.ssl.clusterCAFile requires that net.ssl.CAFile is set.

If net.ssl.clusterCAFile does not specify the .pem file for validating the certificate from a client establishing a connection, the cluster uses the .pem file specified in the net.ssl.CAFile option.

net.ssl.clusterCAFile lets you use separate Certificate Authorities to verify the client to server and server to client portions of the TLS handshake.

Starting in 4.0, on macOS or Windows, you can use a certificate from the operating system’s secure store instead of a PEM key file. See net.ssl.clusterCertificateSelector. When using the secure store, you do not need to, but can, also specify the net.ssl.clusterCAFile.

Windows/macOS Only

If using net.ssl.certificateSelector and/or net.ssl.clusterCertificateSelector, do not use net.ssl.clusterCAFile to specify the root and intermediate CA certificates. Store all CA certificates required to validate the full trust chain of the net.ssl.certificateSelector and/or net.ssl.clusterCertificateSelector certificates in the secure certificate store.

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

net.ssl.CRLFile

Type: string

Deprecated since version 4.2: Use net.tls.CRLFile instead.

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

Note

• Starting in MongoDB 4.0, you cannot specify net.ssl.CRLFile on macOS. Instead, you can use the system SSL certificate store, which uses OCSP (Online Certificate Status Protocol) to validate the revocation status of certificates. See net.ssl.certificateSelector in MongoDB 4.0 and net.tls.certificateSelector in MongoDB 4.2 to use the system SSL certificate store.
• Starting in version 4.4, MongoDB enables, by default, the use of OCSP (Online Certificate Status Protocol) to check for certificate revocation as an alternative to specifying a CRL file or using the system SSL certificate store.

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

net.ssl.allowConnectionsWithoutCertificates

Type: boolean

Deprecated since version 4.2: Use net.tls.allowConnectionsWithoutCertificates instead.

For clients that do not present certificates, mongos or mongod bypasses TLS/SSL certificate validation when establishing the connection.

For clients that present a certificate, however, mongos or mongod performs certificate validation using the root certificate chain specified by CAFile and reject clients with invalid certificates.

Use the net.ssl.allowConnectionsWithoutCertificates option if you have a mixed deployment that includes clients that do not or cannot present certificates to the mongos or mongod.

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

net.ssl.allowInvalidCertificates

Type: boolean

Deprecated since version 4.2: Use net.tls.allowInvalidCertificates instead.

Enable or disable the validation checks for TLS/SSL certificates on other servers in the cluster and allows the use of invalid certificates to connect.

Note

Starting in MongoDB 4.0, if you specify --sslAllowInvalidCertificates or net.ssl.allowInvalidCertificates: true (or in MongoDB 4.2, the alias --tlsAllowInvalidateCertificates or net.tls.allowInvalidCertificates: true) when using x.509 authentication, an invalid certificate is only sufficient to establish a TLS/SSL connection but is insufficient for authentication.

When using the net.ssl.allowInvalidCertificates setting, MongoDB logs a warning regarding the use of the invalid certificate.

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

net.ssl.allowInvalidHostnames

Type: boolean

Default: false

Deprecated since version 4.2.

Use net.tls.allowInvalidHostnames instead.

When net.ssl.allowInvalidHostnames is true, MongoDB disables the validation of the hostnames in TLS/SSL certificates, allowing mongod to connect to MongoDB instances if the hostname their certificates do not match the specified hostname.

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

net.ssl.disabledProtocols

Type: string

Deprecated since version 4.2: Use net.tls.disabledProtocols instead.

Prevents a MongoDB server running with TLS/SSL from accepting incoming connections that use a specific protocol or protocols. To specify multiple protocols, use a comma separated list of protocols.

net.ssl.disabledProtocols recognizes the following protocols: TLS1_0, TLS1_1, TLS1_2, and starting in version 4.0.4 (and 3.6.9), TLS1_3.

• On macOS, you cannot disable TLS1_1 and leave both TLS1_0 and TLS1_2 enabled. You must disable at least one of the other two, for example, TLS1_0,TLS1_1.
• To list multiple protocols, specify as a comma separated list of protocols. For example TLS1_0,TLS1_1.
• Specifying an unrecognized protocol will prevent the server from starting.
• The specified disabled protocols overrides any default disabled protocols.

Starting in version 4.0, MongoDB disables the use of TLS 1.0 if TLS 1.1+ is available on the system. To enable the disabled TLS 1.0, specify none to net.ssl.disabledProtocols. See Disable TLS 1.0.

Members of replica sets and sharded clusters must speak at least one protocol in common.

See also

Disallow Protocols

net.ssl.FIPSMode

Type: boolean

Deprecated since version 4.2: Use net.tls.FIPSMode instead.

Enable or disable the use of the FIPS mode of the TLS/SSL library for the mongos or mongod. Your system must have a FIPS compliant library to use the net.ssl.FIPSMode option.

Note

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

net.compression Option

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net:
   compression:
      compressors: <string>

net.compression.compressors

Default: snappy,zstd,zlib

New in version 3.4.

Specifies the default compressor(s) to use for communication between this mongod or mongos instance and:

• other members of the deployment if the instance is part of a replica set or a sharded cluster
• a mongo shell
• drivers that support the OP_COMPRESSED message format.

MongoDB supports the following compressors:

• snappy
• zlib (Available starting in MongoDB 3.6)
• zstd (Available starting in MongoDB 4.2)

In versions 3.6 and 4.0, mongod and mongos enable network compression by default with snappy as the compressor.

Starting in version 4.2, mongod and mongos instances default to both snappy,zstd,zlib compressors, in that order.

To disable network compression, set the value to disabled.

Important

Messages are compressed when both parties enable network compression. Otherwise, messages between the parties are uncompressed.

If you specify multiple compressors, then the order in which you list the compressors matter as well as the communication initiator. For example, if a mongo shell specifies the following network compressors zlib,snappy and the mongod specifies snappy,zlib, messages between mongo shell and mongod uses zlib.

If the parties do not share at least one common compressor, messages between the parties are uncompressed. For example, if a mongo shell specifies the network compressor zlib and mongod specifies snappy, messages between mongo shell and mongod are not compressed.

net.serviceExecutor

Type: string

Default: synchronous

New in version 3.6.

Determines the threading and execution model mongos or mongod uses to execute client requests. The --serviceExecutor option accepts one of the following values:

Value	Description
synchronous	The mongos or mongod uses synchronous networking and manages its networking thread pool on a per connection basis. Previous versions of MongoDB managed threads in this way.
adaptive	The mongos or mongod uses the new experimental asynchronous networking mode with an adaptive thread pool which manages threads on a per request basis. This mode should have more consistent performance and use less resources when there are more inactive connections than database requests.

security Options

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security:
   keyFile: <string>
   clusterAuthMode: <string>
   authorization: <string>
   transitionToAuth: <boolean>
   javascriptEnabled:  <boolean>
   redactClientLogData: <boolean>
   clusterIpSourceWhitelist:
     - <string>
   sasl:
      hostName: <string>
      serviceName: <string>
      saslauthdSocketPath: <string>
   enableEncryption: <boolean>
   encryptionCipherMode: <string>
   encryptionKeyFile: <string>
   kmip:
      keyIdentifier: <string>
      rotateMasterKey: <boolean>
      serverName: <string>
      port: <string>
      clientCertificateFile: <string>
      clientCertificatePassword: <string>
      clientCertificateSelector: <string>
      serverCAFile: <string>
      connectRetries: <int>
      connectTimeoutMS: <int>
   ldap:
      servers: <string>
      bind:
         method: <string>
         saslMechanisms: <string>
         queryUser: <string>
         queryPassword: <string>
         useOSDefaults: <boolean>
      transportSecurity: <string>
      timeoutMS: <int>
      userToDNMapping: <string>
      authz:
         queryTemplate: <string>
      validateLDAPServerConfig: <boolean>

security.keyFile

Type: string

The path to a key file that stores the shared secret that MongoDB instances use to authenticate to each other in a sharded cluster or replica set. keyFile implies security.authorization. See Internal/Membership Authentication for more information.

Starting in MongoDB 4.2, keyfiles for internal membership authentication use YAML format to allow for multiple keys in a keyfile. The YAML format accepts content of:

• a single key string (same as in earlier versions),
• multiple key strings (each string must be enclosed in quotes), or
• sequence of key strings.

The YAML format is compatible with the existing single-key keyfiles that use the text file format.

security.clusterAuthMode

Type: string

Default: keyFile

The authentication mode used for cluster authentication. If you use internal x.509 authentication, specify so here. This option can have one of the following values:

Value	Description
keyFile	Use a keyfile for authentication. Accept only keyfiles.
sendKeyFile	For rolling upgrade purposes. Send a keyfile for authentication but can accept both keyfiles and x.509 certificates.
sendX509	For rolling upgrade purposes. Send the x.509 certificate for authentication but can accept both keyfiles and x.509 certificates.
x509	Recommended. Send the x.509 certificate for authentication and accept only x.509 certificates.

If --tlsCAFile or tls.CAFile is not specified and you are not using x.509 authentication, the system-wide CA certificate store will be used when connecting to an TLS-enabled server.

If using x.509 authentication, --tlsCAFile or tls.CAFile must be specified unless using --tlsCertificateSelector.

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

security.authorization

Type: string

Default: disabled

Enable or disable Role-Based Access Control (RBAC) to govern each user’s access to database resources and operations.

Set this option to one of the following:

Value	Description
enabled	A user can access only the database resources and actions for which they have been granted privileges.
disabled	A user can access any database and perform any action.

See Role-Based Access Control for more information.

The security.authorization setting is available only for mongod.

security.transitionToAuth

Type: boolean

Default: false

New in version 3.4: Allows the mongod or mongos to accept and create authenticated and non-authenticated connections to and from other mongod and mongos instances in the deployment. Used for performing rolling transition of replica sets or sharded clusters from a no-auth configuration to internal authentication. Requires specifying a internal authentication mechanism such as security.keyFile.

For example, if using keyfiles for internal authentication, the mongod or mongos creates an authenticated connection with any mongod or mongos in the deployment using a matching keyfile. If the security mechanisms do not match, the mongod or mongos utilizes a non-authenticated connection instead.

A mongod or mongos running with security.transitionToAuth does not enforce user access controls. Users may connect to your deployment without any access control checks and perform read, write, and administrative operations.

Note

A mongod or mongos running with internal authentication and without security.transitionToAuth requires clients to connect using user access controls. Update clients to connect to the mongod or mongos using the appropriate user prior to restarting mongod or mongos without security.transitionToAuth.

security.javascriptEnabled

Type: boolean

Default: true

Enables or disables server-side JavaScript execution. When disabled, you cannot use operations that perform server-side execution of JavaScript code, such as the $where query operator, mapReduce command, $accumulator, and $function.

If you do not use these operations, disable server-side scripting.

Starting in version 4.4, the security.javascriptEnabled is available for both mongod and mongos. In earlier versions, the setting is only available for mongod.

security.redactClientLogData

Type: boolean

New in version 3.4: Available in MongoDB Enterprise only.

A mongod or mongos running with security.redactClientLogData redacts any message accompanying a given log event before logging. This prevents the mongod or mongos from writing potentially sensitive data stored on the database to the diagnostic log. Metadata such as error or operation codes, line numbers, and source file names are still visible in the logs.

Use security.redactClientLogData in conjunction with Encryption at Rest and TLS/SSL (Transport Encryption) to assist compliance with regulatory requirements.

For example, a MongoDB deployment might store Personally Identifiable Information (PII) in one or more collections. The mongod or mongos logs events such as those related to CRUD operations, sharding metadata, etc. It is possible that the mongod or mongos may expose PII as a part of these logging operations. A mongod or mongos running with security.redactClientLogData removes any message accompanying these events before being output to the log, effectively removing the PII.

Diagnostics on a mongod or mongos running with security.redactClientLogData may be more difficult due to the lack of data related to a log event. See the process logging manual page for an example of the effect of security.redactClientLogData on log output.

On a running mongod or mongos, use setParameter with the redactClientLogData parameter to configure this setting.

security.clusterIpSourceWhitelist

Type: list

New in version 3.6.

A list of IP addresses/CIDR (Classless Inter-Domain Routing) ranges against which the mongod validates authentication requests from other members of the replica set and, if part of a sharded cluster, the mongos instances. The mongod verifies that the originating IP is either explicitly in the list or belongs to a CIDR range in the list. If the IP address is not present, the server does not authenticate the mongod or mongos.

security.clusterIpSourceWhitelist has no effect on a mongod started without authentication.

security.clusterIpSourceWhitelist requires specifying each IPv4/6 address or Classless Inter-Domain Routing (CIDR) range as a YAML list:

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security:
  clusterIpSourceWhitelist:
    - 192.0.2.0/24
    - 127.0.0.1
    - ::1

Important

Ensure security.clusterIpSourceWhitelist includes the IP address or CIDR ranges that include the IP address of each replica set member or mongos in the deployment to ensure healthy communication between cluster components.

Key Management Configuration Options

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security:
   enableEncryption: <boolean>
   encryptionCipherMode: <string>
   encryptionKeyFile: <string>
   kmip:
      keyIdentifier: <string>
      rotateMasterKey: <boolean>
      serverName: <string>
      port: <string>
      clientCertificateFile: <string>
      clientCertificatePassword: <string>
      clientCertificateSelector: <string>
      serverCAFile: <string>
      connectRetries: <int>
      connectTimeoutMS: <int>

security.enableEncryption

Type: boolean

Default: false

New in version 3.2: Enables encryption for the WiredTiger storage engine. You must set to true to pass in encryption keys and configurations.

Enterprise Feature

Available in MongoDB Enterprise only.

security.encryptionCipherMode

Type: string

Default: AES256-CBC

New in version 3.2.

The cipher mode to use for encryption at rest:

Mode	Description
AES256-CBC	256-bit Advanced Encryption Standard in Cipher Block Chaining Mode
AES256-GCM	256-bit Advanced Encryption Standard in Galois/Counter Mode Available only on Linux. Changed in version 4.0: MongoDB Enterprise on Windows no longer supports AES256-GCM. This cipher is now available only on Linux.

Enterprise Feature

Available in MongoDB Enterprise only.

security.encryptionKeyFile

Type: string

New in version 3.2.

The path to the local keyfile when managing keys via process other than KMIP. Only set when managing keys via process other than KMIP. If data is already encrypted using KMIP, MongoDB will throw an error.

Requires security.enableEncryption to be true.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.keyIdentifier

Type: string

New in version 3.2.

Unique KMIP identifier for an existing key within the KMIP server. Include to use the key associated with the identifier as the system key. You can only use the setting the first time you enable encryption for the mongod instance. Requires security.enableEncryption to be true.

If unspecified, MongoDB will request that the KMIP server create a new key to utilize as the system key.

If the KMIP server cannot locate a key with the specified identifier or the data is already encrypted with a key, MongoDB will throw an error.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.rotateMasterKey

Type: boolean

Default: false

New in version 3.2.

If true, rotate the master key and re-encrypt the internal keystore.

Enterprise Feature

Available in MongoDB Enterprise only.

See also

KMIP Master Key Rotation

security.kmip.serverName

Type: string

New in version 3.2.

Hostname or IP address of the KMIP server to connect to. Requires security.enableEncryption to be true.

Starting in MongoDB 4.2.1 (and 4.0.14), you can specify multiple KMIP servers as a comma-separated list, e.g. server1.example.com,server2.example.com. On startup, the mongod will attempt to establish a connection to each server in the order listed, and will select the first server to which it can successfully establish a connection. KMIP server selection occurs only at startup.

When connecting to a KMIP server, the mongod verifies that the specified security.kmip.serverName matches the Subject Alternative Name SAN (or, if SAN is not present, the Common Name CN) in the certificate presented by the KMIP server. If SAN is present, mongod does not match against the CN. If the hostname does not match the SAN (or CN), the mongod will fail to connect.

Starting in MongoDB 4.2, when performing comparison of SAN, MongoDB supports comparison of DNS names or IP addresses. In previous versions, MongoDB only supports comparisons of DNS names.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.port

Type: string

Default: 5696

New in version 3.2.

Port number to use to communicate with the KMIP server. Requires security.kmip.serverName. Requires security.enableEncryption to be true.

If specifying multiple KMIP servers with security.kmip.serverName, the mongod will use the port specified with security.kmip.port for all provided KMIP servers.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.clientCertificateFile

Type: string

New in version 3.2.

String containing the path to the client certificate used for authenticating MongoDB to the KMIP server. Requires that a security.kmip.serverName be provided.

Note

Starting in 4.0, on macOS or Windows, you can use a certificate from the operating system’s secure store instead of a PEM key file. See security.kmip.clientCertificateSelector.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.clientCertificatePassword

Type: string

New in version 3.2.

The password to decrypt the client certificate (i.e. security.kmip.clientCertificateFile), used to authenticate MongoDB to the KMIP server. Use the option only if the certificate is encrypted.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.clientCertificateSelector

Type: string

New in version 4.0: Available on Windows and macOS as an alternative to security.kmip.clientCertificateFile.

security.kmip.clientCertificateFile and security.kmip.clientCertificateSelector options are mutually exclusive. You can only specify one.

Specifies a certificate property in order to select a matching certificate from the operating system’s certificate store to authenticate MongoDB to the KMIP server.

security.kmip.clientCertificateSelector accepts an argument of the format <property>=<value> where the property can be one of the following:

Property	Value type	Description
subject	ASCII string	Subject name or common name on certificate
thumbprint	hex string	A sequence of bytes, expressed as hexadecimal, used to identify a public key by its SHA-1 digest. The thumbprint is sometimes referred to as a fingerprint.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.serverCAFile

Type: string

New in version 3.2.

Path to CA File. Used for validating secure client connection to KMIP server.

Note

Starting in 4.0, on macOS or Windows, you can use a certificate from the operating system’s secure store instead of a PEM key file. See security.kmip.clientCertificateSelector. When using the secure store, you do not need to, but can, also specify the security.kmip.serverCAFile.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.connectRetries

Type: int

Default: 0

New in version 4.4.

How many times to retry the initial connection to the KMIP server. Use together with connectTimeoutMS to control how long the mongod waits for a response between each retry.

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.connectTimeoutMS

Type: int

Default: 5000

New in version 4.4.

Timeout in milliseconds to wait for a response from the KMIP server. If the connectRetries setting is specified, the mongod will wait up to the value specified with connectTimeoutMS for each retry.

Value must be 1000 or greater.

Enterprise Feature

Available in MongoDB Enterprise only.

security.sasl Options

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security:
   sasl:
      hostName: <string>
      serviceName: <string>
      saslauthdSocketPath: <string>

security.sasl.hostName

Type: string

A fully qualified server domain name for the purpose of configuring SASL and Kerberos authentication. The SASL hostname overrides the hostname only for the configuration of SASL and Kerberos.

For mongo shell and other MongoDB tools to connect to the new hostName, see the gssapiHostName option in the mongo shell and other tools.

security.sasl.serviceName

Type: string

Registered name of the service using SASL. This option allows you to override the default Kerberos service name component of the Kerberos principal name, on a per-instance basis. If unspecified, the default value is mongodb.

MongoDB permits setting this option only at startup. The setParameter can not change this setting.

This option is available only in MongoDB Enterprise.

Important

Ensure that your driver supports alternate service names. For mongo shell and other MongoDB tools to connect to the new serviceName, see the gssapiServiceName option.

security.sasl.saslauthdSocketPath

Type: string

The path to the UNIX domain socket file for saslauthd.

security.ldap Options

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security:
   ldap:
      servers: <string>
      bind:
         method: <string>
         saslMechanisms: <string>
         queryUser: <string>
         queryPassword: <string>
         useOSDefaults: <boolean>
      transportSecurity: <string>
      timeoutMS: <int>
      userToDNMapping: <string>
      authz:
         queryTemplate: <string>
      validateLDAPServerConfig: <boolean>

security.ldap.servers

Type: string

New in version 3.4: Available in MongoDB Enterprise only.

The LDAP server against which the mongod or mongos authenticates users or determines what actions a user is authorized to perform on a given database. If the LDAP server specified has any replicated instances, you may specify the host and port of each replicated server in a comma-delimited list.

If your LDAP infrastructure partitions the LDAP directory over multiple LDAP servers, specify one LDAP server or any of its replicated instances to security.ldap.servers. MongoDB supports following LDAP referrals as defined in RFC 4511 4.1.10. Do not use security.ldap.servers for listing every LDAP server in your infrastructure.

This setting can be configured on a running mongod or mongos using setParameter.

If unset, mongod or mongos cannot use LDAP authentication or authorization.

security.ldap.bind.queryUser

Type: string

New in version 3.4: Available in MongoDB Enterprise only.

The identity with which mongod or mongos binds as, when connecting to or performing queries on an LDAP server.

Only required if any of the following are true:

• Using LDAP authorization.
• Using an LDAP query for security.ldap.userToDNMapping.
• The LDAP server disallows anonymous binds

You must use queryUser with queryPassword.

If unset, mongod or mongos will not attempt to bind to the LDAP server.

This setting can be configured on a running mongod or mongos using setParameter.

Note

Windows MongoDB deployments can use bindWithOSDefaults instead of queryUser and queryPassword. You cannot specify both queryUser and bindWithOSDefaults at the same time.

security.ldap.bind.queryPassword

Type: string

New in version 3.4: Available in MongoDB Enterprise only.

The password used to bind to an LDAP server when using queryUser. You must use queryPassword with queryUser.

If unset, mongod or mongos will not attempt to bind to the LDAP server.

This setting can be configured on a running mongod or mongos using setParameter.

Note

Windows MongoDB deployments can use bindWithOSDefaults instead of queryPassword and queryPassword. You cannot specify both queryPassword and bindWithOSDefaults at the same time.

security.ldap.bind.useOSDefaults

Type: boolean

Default: false

New in version 3.4: Available in MongoDB Enterprise for the Windows platform only.

Allows mongod or mongos to authenticate, or bind, using your Windows login credentials when connecting to the LDAP server.

Only required if:

• Using LDAP authorization.
• Using an LDAP query for username transformation.
• The LDAP server disallows anonymous binds

Use useOSDefaults to replace queryUser and queryPassword.

security.ldap.bind.method

Type: string

Default: simple

New in version 3.4: Available in MongoDB Enterprise only.

The method mongod or mongos uses to authenticate to an LDAP server. Use with queryUser and queryPassword to connect to the LDAP server.

method supports the following values:

• simple - mongod or mongos uses simple authentication.
• sasl - mongod or mongos uses SASL protocol for authentication

If you specify sasl, you can configure the available SASL mechanisms using security.ldap.bind.saslMechanisms. mongod or mongos defaults to using DIGEST-MD5 mechanism.

security.ldap.bind.saslMechanisms

Type: string

Default: DIGEST-MD5

New in version 3.4: Available in MongoDB Enterprise only.

A comma-separated list of SASL mechanisms mongod or mongos can use when authenticating to the LDAP server. The mongod or mongos and the LDAP server must agree on at least one mechanism. The mongod or mongos dynamically loads any SASL mechanism libraries installed on the host machine at runtime.

Install and configure the appropriate libraries for the selected SASL mechanism(s) on both the mongod or mongos host and the remote LDAP server host. Your operating system may include certain SASL libraries by default. Defer to the documentation associated with each SASL mechanism for guidance on installation and configuration.

If using the GSSAPI SASL mechanism for use with Kerberos Authentication, verify the following for the mongod or mongos host machine:

Linux

• The KRB5_CLIENT_KTNAME environment variable resolves to the name of the client Linux Keytab Files for the host machine. For more on Kerberos environment variables, please defer to the Kerberos documentation.
• The client keytab includes a User Principal for the mongod or mongos to use when connecting to the LDAP server and execute LDAP queries.

Windows

If connecting to an Active Directory server, the Windows Kerberos configuration automatically generates a Ticket-Granting-Ticket when the user logs onto the system. Set useOSDefaults to true to allow mongod or mongos to use the generated credentials when connecting to the Active Directory server and execute queries.

Set method to sasl to use this option.

Note

For a complete list of SASL mechanisms see the IANA listing. Defer to the documentation for your LDAP or Active Directory service for identifying the SASL mechanisms compatible with the service.

MongoDB is not a source of SASL mechanism libraries, nor is the MongoDB documentation a definitive source for installing or configuring any given SASL mechanism. For documentation and support, defer to the SASL mechanism library vendor or owner.

For more information on SASL, defer to the following resources:

• For Linux, please see the Cyrus SASL documentation.
• For Windows, please see the Windows SASL documentation.

security.ldap.transportSecurity

Type: string

Default: tls

New in version 3.4: Available in MongoDB Enterprise only.

By default, mongod or mongos creates a TLS/SSL secured connection to the LDAP server.

For Linux deployments, you must configure the appropriate TLS Options in /etc/openldap/ldap.conf file. Your operating system’s package manager creates this file as part of the MongoDB Enterprise installation, via the libldap dependency. See the documentation for TLS Options in the ldap.conf OpenLDAP documentation for more complete instructions.

For Windows deployment, you must add the LDAP server CA certificates to the Windows certificate management tool. The exact name and functionality of the tool may vary depending on operating system version. Please see the documentation for your version of Windows for more information on certificate management.

Set transportSecurity to none to disable TLS/SSL between mongod or mongos and the LDAP server.

Warning

Setting transportSecurity to none transmits plaintext information and possibly credentials between mongod or mongos and the LDAP server.

security.ldap.timeoutMS

Type: int

Default: 10000

New in version 3.4: Available in MongoDB Enterprise only.

The amount of time in milliseconds mongod or mongos should wait for an LDAP server to respond to a request.

Increasing the value of timeoutMS may prevent connection failure between the MongoDB server and the LDAP server, if the source of the failure is a connection timeout. Decreasing the value of timeoutMS reduces the time MongoDB waits for a response from the LDAP server.

This setting can be configured on a running mongod or mongos using setParameter.

security.ldap.userToDNMapping

Type: string

New in version 3.4: Available in MongoDB Enterprise only.

Maps the username provided to mongod or mongos for authentication to a LDAP Distinguished Name (DN). You may need to use userToDNMapping to transform a username into an LDAP DN in the following scenarios:

• Performing LDAP authentication with simple LDAP binding, where users authenticate to MongoDB with usernames that are not full LDAP DNs.
• Using an LDAP authorization query template that requires a DN.
• Transforming the usernames of clients authenticating to Mongo DB using different authentication mechanisms (e.g. x.509, kerberos) to a full LDAP DN for authorization.

userToDNMapping expects a quote-enclosed JSON-string representing an ordered array of documents. Each document contains a regular expression match and either a substitution or ldapQuery template used for transforming the incoming username.

Each document in the array has the following form:

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{
  match: "<regex>"
  substitution: "<LDAP DN>" | ldapQuery: "<LDAP Query>"
}

Field	Description	Example
match	An ECMAScript-formatted regular expression (regex) to match against a provided username. Each parenthesis-enclosed section represents a regex capture group used by substitution or ldapQuery.	"(.+)ENGINEERING" "(.+)DBA"
substitution	An LDAP distinguished name (DN) formatting template that converts the authentication name matched by the match regex into a LDAP DN. Each curly bracket-enclosed numeric value is replaced by the corresponding regex capture group extracted from the authentication username via the match regex. The result of the substitution must be an RFC4514 escaped string.	"cn={0},ou=engineering, dc=example,dc=com"
ldapQuery	A LDAP query formatting template that inserts the authentication name matched by the match regex into an LDAP query URI encoded respecting RFC4515 and RFC4516. Each curly bracket-enclosed numeric value is replaced by the corresponding regex capture group extracted from the authentication username via the match expression. mongod or mongos executes the query against the LDAP server to retrieve the LDAP DN for the authenticated user. mongod or mongos requires exactly one returned result for the transformation to be successful, or mongod or mongos skips this transformation.	"ou=engineering,dc=example, dc=com??one?(user={0})"

Note

An explanation of RFC4514, RFC4515, RFC4516, or LDAP queries is out of scope for the MongoDB Documentation. Please review the RFC directly or use your preferred LDAP resource.

For each document in the array, you must use either substitution or ldapQuery. You cannot specify both in the same document.

When performing authentication or authorization, mongod or mongos steps through each document in the array in the given order, checking the authentication username against the match filter. If a match is found, mongod or mongos applies the transformation and uses the output for authenticating the user. mongod or mongos does not check the remaining documents in the array.

If the given document does not match the provided authentication name, mongod or mongos continues through the list of documents to find additional matches. If no matches are found in any document, or the transformation the document describes fails, mongod or mongos returns an error.

Starting in MongoDB 4.4, mongod or mongos also returns an error if one of the transformations cannot be evaluated due to networking or authentication failures to the LDAP server. mongod or mongos rejects the connection request and does not check the remaining documents in the array.

Example

The following shows two transformation documents. The first document matches against any string ending in @ENGINEERING, placing anything preceeding the suffix into a regex capture group. The second document matches against any string ending in @DBA, placing anything preceeding the suffix into a regex capture group.

Important

You must pass the array to userToDNMapping as a string.

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"[
   {
      match: "(.+)@ENGINEERING.EXAMPLE.COM",
      substitution: "cn={0},ou=engineering,dc=example,dc=com"
   },
   {
      match: "(.+)@DBA.EXAMPLE.COM",
      ldapQuery: "ou=dba,dc=example,dc=com??one?(user={0})"

   }

]"

A user with username alice@ENGINEERING.EXAMPLE.COM matches the first document. The regex capture group {0} corresponds to the string alice. The resulting output is the DN "cn=alice,ou=engineering,dc=example,dc=com".

A user with username bob@DBA.EXAMPLE.COM matches the second document. The regex capture group {0} corresponds to the string bob. The resulting output is the LDAP query "ou=dba,dc=example,dc=com??one?(user=bob)". mongod or mongos executes this query against the LDAP server, returning the result "cn=bob,ou=dba,dc=example,dc=com".

If userToDNMapping is unset, mongod or mongos applies no transformations to the username when attempting to authenticate or authorize a user against the LDAP server.

This setting can be configured on a running mongod or mongos using the setParameter database command.

security.ldap.authz.queryTemplate

Type: string

New in version 3.4: Available in MongoDB Enterprise only.

A relative LDAP query URL formatted conforming to RFC4515 and RFC4516 that mongod executes to obtain the LDAP groups to which the authenticated user belongs to. The query is relative to the host or hosts specified in security.ldap.servers.

In the URL, you can use the following substitution tokens:

Substitution Token	Description
{USER}	Substitutes the authenticated username, or the transformed username if a userToDNMapping is specified.
{PROVIDED_USER}	Substitutes the supplied username, i.e. before either authentication or LDAP transformation. New in version 4.2.

When constructing the query URL, ensure that the order of LDAP parameters respects RFC4516:

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[ dn  [ ? [attributes] [ ? [scope] [ ? [filter] [ ? [Extensions] ] ] ] ] ]

If your query includes an attribute, mongod assumes that the query retrieves a list of the DNs which this entity is a member of.

If your query does not include an attribute, mongod assumes the query retrieves all entities which the user is member of.

For each LDAP DN returned by the query, mongod assigns the authorized user a corresponding role on the admin database. If a role on the on the admin database exactly matches the DN, mongod grants the user the roles and privileges assigned to that role. See the db.createRole() method for more information on creating roles.

Example

This LDAP query returns any groups listed in the LDAP user object’s memberOf attribute.

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"{USER}?memberOf?base"

Your LDAP configuration may not include the memberOf attribute as part of the user schema, may possess a different attribute for reporting group membership, or may not track group membership through attributes. Configure your query with respect to your own unique LDAP configuration.

If unset, mongod cannot authorize users using LDAP.

This setting can be configured on a running mongod using the setParameter database command.

Note

An explanation of RFC4515, RFC4516 or LDAP queries is out of scope for the MongoDB Documentation. Please review the RFC directly or use your preferred LDAP resource.

security.ldap.validateLDAPServerConfig

Type: boolean

Default: true

Available in MongoDB Enterprise

A flag that determines if the mongod or mongos instance checks the availability of the LDAP server(s) as part of its startup:

• If true, the mongod or mongos instance performs the availability check and only continues to start up if the LDAP server is available.
• If false, the mongod or mongos instance skips the availability check; i.e. the instance starts up even if the LDAP server is unavailable.

setParameter Option

setParameter

Set MongoDB parameter or parameters described in MongoDB Server Parameters

To set parameters in the YAML configuration file, use the following format:

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setParameter:
   <parameter1>: <value1>
   <parameter2>: <value2>

For example, to specify the enableLocalhostAuthBypass in the configuration file:

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setParameter:
   enableLocalhostAuthBypass: false

LDAP Parameters

setParameter.ldapUserCacheInvalidationInterval

Type: int

Default: 30

For use with mongod servers using LDAP Authorization.

The interval (in seconds) mongod waits between external user cache flushes. After mongod flushes the external user cache, MongoDB reacquires authorization data from the LDAP server the next time an LDAP-authorized user issues an operation.

Increasing the value specified increases the amount of time mongod and the LDAP server can be out of sync, but reduces the load on the LDAP server. Conversely, decreasing the value specified decreases the time mongod and the LDAP server can be out of sync while increasing the load on the LDAP server.

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setParameter:
   ldapUserCacheInvalidationInterval: <int>

storage Options

Starting in version 4.4

• MongoDB removes the storage.indexBuildRetry option and the corresponding --noIndexBuildRetry command-line option.
• MongoDB deprecates storage.wiredTiger.engineConfig.maxCacheOverflowFileSizeGB option. The option has no effect starting in MongoDB 4.4.

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storage:
   dbPath: <string>
   journal:
      enabled: <boolean>
      commitIntervalMs: <num>
   directoryPerDB: <boolean>
   syncPeriodSecs: <int>
   engine: <string>
   wiredTiger:
      engineConfig:
         cacheSizeGB: <number>
         journalCompressor: <string>
         directoryForIndexes: <boolean>
         maxCacheOverflowFileSizeGB: <number> // deprecated in MongoDB 4.4
      collectionConfig:
         blockCompressor: <string>
      indexConfig:
         prefixCompression: <boolean>
   inMemory:
      engineConfig:
         inMemorySizeGB: <number>
   oplogMinRetentionHours: <double>

storage.dbPath

Type: string

Default:

• /data/db on Linux and macOS
• \data\db on Windows

The directory where the mongod instance stores its data.

The storage.dbPath setting is available only for mongod.

Configuration Files

The default mongod.conf configuration file included with package manager installations uses the following platform-specific default values for storage.dbPath:

Platform	Package Manager	Default storage.dbPath
RHEL / CentOS and Amazon	yum	/var/lib/mongo
SUSE	zypper	/var/lib/mongo
Ubuntu and Debian	apt	/var/lib/mongodb
macOS	brew	/usr/local/var/mongodb

The Linux package init scripts do not expect storage.dbPath to change from the defaults. If you use the Linux packages and change storage.dbPath, you will have to use your own init scripts and disable the built-in scripts.

storage.journal.enabled

Type: boolean

Default: true on 64-bit systems, false on 32-bit systems

Enable or disable the durability journal to ensure data files remain valid and recoverable. This option applies only when you specify the storage.dbPath setting. mongod enables journaling by default.

The storage.journal.enabled setting is available only for mongod.

Not available for mongod instances that use the in-memory storage engine.

Starting in MongoDB 4.0, you cannot specify --nojournal option or storage.journal.enabled: false for replica set members that use the WiredTiger storage engine.

storage.journal.commitIntervalMs

Type: number

Default: 100

The maximum amount of time in milliseconds that the mongod process allows between journal operations. Values can range from 1 to 500 milliseconds. Lower values increase the durability of the journal, at the expense of disk performance.

On WiredTiger, the default journal commit interval is 100 milliseconds. Additionally, a write that includes or implies j:true will cause an immediate sync of the journal. For details or additional conditions that affect the frequency of the sync, see Journaling Process.

The storage.journal.commitIntervalMs setting is available only for mongod.

Not available for mongod instances that use the in-memory storage engine.

Note

Known Issue in 4.2.0: The storage.journal.commitIntervalMs is missing in 4.2.0.

storage.directoryPerDB

Type: boolean

Default: false

When true, MongoDB uses a separate directory to store data for each database. The directories are under the storage.dbPath directory, and each subdirectory name corresponds to the database name.

The storage.directoryPerDB setting is available only for mongod.

Not available for mongod instances that use the in-memory storage engine.

To change the storage.directoryPerDB option for existing deployments:

• For standalone instances:
  1. Use mongodump on the existing mongod instance to generate a backup.
  2. Stop the mongod instance.
  3. Add the storage.directoryPerDB value and configure a new data directory
  4. Restart the mongod instance.
  5. Use mongorestore to populate the new data directory.
• For replica sets:
  1. Stop a secondary member.
  2. Add the storage.directoryPerDB value and configure a new data directory to that secondary member.
  3. Restart that secondary.
  4. Use initial sync to populate the new data directory.
  5. Update remaining secondaries in the same fashion.
  6. Step down the primary, and update the stepped-down member in the same fashion.

storage.syncPeriodSecs

Type: number

Default: 60

The amount of time that can pass before MongoDB flushes data to the data files via an fsync operation.

Do not set this value on production systems. In almost every situation, you should use the default setting.

Warning

If you set storage.syncPeriodSecs to 0, MongoDB will not sync the memory mapped files to disk.

The mongod process writes data very quickly to the journal and lazily to the data files. storage.syncPeriodSecs has no effect on the journal files or journaling, but if storage.syncPeriodSecs is set to 0 the journal will eventually consume all available disk space. If you set storage.syncPeriodSecs to 0 for testing purposes, you should also set --nojournal to true.

The serverStatus command reports the background flush thread’s status via the backgroundFlushing field.

The storage.syncPeriodSecs setting is available only for mongod.

Not available for mongod instances that use the in-memory storage engine.

storage.engine

Default: wiredTiger

Note

Starting in version 4.2, MongoDB removes the deprecated MMAPv1 storage engine.

The storage engine for the mongod database. Available values include:

Value	Description
wiredTiger	To specify the WiredTiger Storage Engine.
inMemory	To specify the In-Memory Storage Engine. New in version 3.2: Available in MongoDB Enterprise only.

If you attempt to start a mongod with a storage.dbPath that contains data files produced by a storage engine other than the one specified by storage.engine, mongod will refuse to start.

storage.oplogMinRetentionHours

Type: double

New in version 4.4: Specifies the minimum number of hours to preserve an oplog entry, where the decimal values represent the fractions of an hour. For example, a value of 1.5 represents one hour and thirty minutes.

The value must be greater than or equal to 0. A value of 0 indicates that the mongod should truncate the oplog starting with the oldest entries to maintain the configured maximum oplog size.

Defaults to 0.

A mongod started with oplogMinRetentionHours only removes an oplog entry if:

• The oplog has reached the maximum configured oplog size and
• The oplog entry is older than the configured number of hours based on the host system clock.

The mongod has the following behavior when configured with a minimum oplog retention period:

• The oplog can grow without constraint so as to retain oplog entries for the configured number of hours. This may result in reduction or exhaustion of system disk space due to a combination of high write volume and large retention period.
• If the oplog grows beyond its maximum size, the mongod may continue to hold that disk space even if the oplog returns to its maximum size or is configured for a smaller maximum size. See Reducing Oplog Size Does Not Immediately Return Disk Space.
• The mongod compares the system wall clock to an oplog entries creation wall clock time when enforcing oplog entry retention. Clock drift between cluster components may result in unexpected oplog retention behavior. See Clock Synchronization for more information on clock synchronization across cluster members.

To change the minimum oplog retention period after starting the mongod, use replSetResizeOplog. replSetResizeOplog enables you to resize the oplog dynamically without restarting the mongod process. To persist the changes made using replSetResizeOplog through a restart, update the value of oplogMinRetentionHours.

storage.wiredTiger Options

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storage:
   wiredTiger:
      engineConfig:
         cacheSizeGB: <number>
         journalCompressor: <string>
         directoryForIndexes: <boolean>
         maxCacheOverflowFileSizeGB: <number>   // Deprecated in MongoDB 4.4
      collectionConfig:
         blockCompressor: <string>
      indexConfig:
         prefixCompression: <boolean>

storage.wiredTiger.engineConfig.cacheSizeGB

Type: float

Defines the maximum size of the internal cache that WiredTiger will use for all data. The memory consumed by an index build (see maxIndexBuildMemoryUsageMegabytes) is separate from the WiredTiger cache memory.

Values can range from 0.25 GB to 10000 GB.

Starting in MongoDB 3.4, the default WiredTiger internal cache size is the larger of either:

• 50% of (RAM - 1 GB), or
• 256 MB.

For example, on a system with a total of 4GB of RAM the WiredTiger cache will use 1.5GB of RAM (0.5 * (4 GB - 1 GB) = 1.5 GB). Conversely, a system with a total of 1.25 GB of RAM will allocate 256 MB to the WiredTiger cache because that is more than half of the total RAM minus one gigabyte (0.5 * (1.25 GB - 1 GB) = 128 MB < 256 MB).

Note

In some instances, such as when running in a container, the database can have memory constraints that are lower than the total system memory. In such instances, this memory limit, rather than the total system memory, is used as the maximum RAM available.

To see the memory limit, see hostInfo.system.memLimitMB.

Avoid increasing the WiredTiger internal cache size above its default value.

With WiredTiger, MongoDB utilizes both the WiredTiger internal cache and the filesystem cache.

Via the filesystem cache, MongoDB automatically uses all free memory that is not used by the WiredTiger cache or by other processes.

Note

The storage.wiredTiger.engineConfig.cacheSizeGB limits the size of the WiredTiger internal cache. The operating system will use the available free memory for filesystem cache, which allows the compressed MongoDB data files to stay in memory. In addition, the operating system will use any free RAM to buffer file system blocks and file system cache.

To accommodate the additional consumers of RAM, you may have to decrease WiredTiger internal cache size.

The default WiredTiger internal cache size value assumes that there is a single mongod instance per machine. If a single machine contains multiple MongoDB instances, then you should decrease the setting to accommodate the other mongod instances.

If you run mongod in a container (e.g. lxc, cgroups, Docker, etc.) that does not have access to all of the RAM available in a system, you must set storage.wiredTiger.engineConfig.cacheSizeGB to a value less than the amount of RAM available in the container. The exact amount depends on the other processes running in the container. See memLimitMB.

storage.wiredTiger.engineConfig.journalCompressor

Default: snappy

Specifies the type of compression to use to compress WiredTiger journal data.

Available compressors are:

• none
• snappy
• zlib
• zstd (Available starting in MongoDB 4.2)

storage.wiredTiger.engineConfig.directoryForIndexes

Type: boolean

Default: false

When storage.wiredTiger.engineConfig.directoryForIndexes is true, mongod stores indexes and collections in separate subdirectories under the data (i.e. storage.dbPath) directory. Specifically, mongod stores the indexes in a subdirectory named index and the collection data in a subdirectory named collection.

By using a symbolic link, you can specify a different location for the indexes. Specifically, when mongod instance is not running, move the index subdirectory to the destination and create a symbolic link named index under the data directory to the new destination.

storage.wiredTiger.engineConfig.maxCacheOverflowFileSizeGB

Type: float

Deprecated in MongoDB 4.4

MongoDB deprecates the storage.wiredTiger.engineConfig.maxCacheOverflowFileSizeGB option. The option has no effect starting in MongoDB 4.4.

Specifies the maximum size (in GB) for the “lookaside (or cache overflow) table” file WiredTigerLAS.wt for MongoDB 4.2.1-4.2.x and 4.0.12-4.0.x. The file no longer exists starting in version 4.4.

The setting can accept the following values:

Value	Description
0	The default value. If set to 0, the file size is unbounded.
number >= 0.1	The maximum size (in GB). If the WiredTigerLAS.wt file exceeds this size, mongod exits with a fatal assertion. You can clear the WiredTigerLAS.wt file and restart mongod.

To change the maximum size during runtime, use the wiredTigerMaxCacheOverflowSizeGB parameter.

Available starting in MongoDB 4.2.1 (and 4.0.12)

storage.wiredTiger.collectionConfig.blockCompressor

Default: snappy

Specifies the default compression for collection data. You can override this on a per-collection basis when creating collections.

Available compressors are:

• none
• snappy
• zlib
• zstd (Available starting MongoDB 4.2)

storage.wiredTiger.collectionConfig.blockCompressor affects all collections created. If you change the value of storage.wiredTiger.collectionConfig.blockCompressor on an existing MongoDB deployment, all new collections will use the specified compressor. Existing collections will continue to use the compressor specified when they were created, or the default compressor at that time.

storage.wiredTiger.indexConfig.prefixCompression

Default: true

Enables or disables prefix compression for index data.

Specify true for storage.wiredTiger.indexConfig.prefixCompression to enable prefix compression for index data, or false to disable prefix compression for index data.

The storage.wiredTiger.indexConfig.prefixCompression setting affects all indexes created. If you change the value of storage.wiredTiger.indexConfig.prefixCompression on an existing MongoDB deployment, all new indexes will use prefix compression. Existing indexes are not affected.

storage.inmemory Options

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storage:
   inMemory:
      engineConfig:
         inMemorySizeGB: <number>

storage.inMemory.engineConfig.inMemorySizeGB

Type: float

Default: 50% of physical RAM less 1 GB

Changed in version 3.4: Values can range from 256MB to 10TB and can be a float.

Maximum amount of memory to allocate for in-memory storage engine data, including indexes, oplog if the mongod is part of replica set, replica set or sharded cluster metadata, etc.

By default, the in-memory storage engine uses 50% of physical RAM minus 1 GB.

Enterprise Feature

Available in MongoDB Enterprise only.

operationProfiling Options

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operationProfiling:
   mode: <string>
   slowOpThresholdMs: <int>
   slowOpSampleRate: <double>

operationProfiling.mode

Type: string

Default: off

Specifies which operations should be profiled. The following profiler levels are available:

Level	Description
off	The profiler is off and does not collect any data. This is the default profiler level.
slowOp	The profiler collects data for operations that take longer than the value of slowms.
all	The profiler collects data for all operations.

Important

Profiling can impact performance and shares settings with the system log. Carefully consider any performance and security implications before configuring and enabling the profiler on a production deployment.

See Profiler Overhead for more information on potential performance degradation.

operationProfiling.slowOpThresholdMs

Type: integer

Default: 100

The slow operation time threshold, in milliseconds. Operations that run for longer than this threshold are considered slow.

When logLevel is set to 0, MongoDB records slow operations to the diagnostic log at a rate determined by slowOpSampleRate. Starting in MongoDB 4.2, the secondaries of replica sets log all oplog entry messages that take longer than the slow operation threshold to apply regardless of the sample rate.

At higher logLevel settings, all operations appear in the diagnostic log regardless of their latency with the following exception: the logging of slow oplog entry messages by the secondaries. The secondaries log only the slow oplog entries; increasing the logLevel does not log all oplog entries.

Changed in version 4.0: The slowOpThresholdMs setting is available for mongod and mongos. In earlier versions, slowOpThresholdMs is available for mongod only.

• For mongod instances, the setting affects both the diagnostic log and, if enabled, the profiler.
• For mongos instances, the setting affects the diagnostic log only and not the profiler since profiling is not available on mongos.

operationProfiling.slowOpSampleRate

Type: double

Default: 1.0

The fraction of slow operations that should be profiled or logged. operationProfiling.slowOpSampleRate accepts values between 0 and 1, inclusive.

operationProfiling.slowOpSampleRate does not affect the slow oplog entry logging by the secondary members of a replica set. Secondary members log all oplog entries that take longer than the slow operation threshold regardless of the operationProfiling.slowOpSampleRate.

Changed in version 4.0: The slowOpSampleRate setting is available for mongod and mongos. In earlier versions, slowOpSampleRate is available for mongod only.

• For mongod instances, the setting affects both the diagnostic log and, if enabled, the profiler.
• For mongos instances, the setting affects the diagnostic log only and not the profiler since profiling is not available on mongos.

replication Options

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replication:
   oplogSizeMB: <int>
   replSetName: <string>
   enableMajorityReadConcern: <boolean>

replication.oplogSizeMB

Type: integer

The maximum size in megabytes for the replication operation log (i.e., the oplog).

Note

Starting in MongoDB 4.0, the oplog can grow past its configured size limit to avoid deleting the majority commit point.

By default, the mongod process creates an oplog based on the maximum amount of space available. For 64-bit systems, the oplog is typically 5% of available disk space.

Once the mongod has created the oplog for the first time, changing the replication.oplogSizeMB option will not affect the size of the oplog. To change the maximum oplog size after starting the mongod, use replSetResizeOplog. replSetResizeOplog enables you to resize the oplog dynamically without restarting the mongod process. To persist the changes made using replSetResizeOplog through a restart, update the value of oplogSizeMB.

See Oplog Size for more information.

The replication.oplogSizeMB setting is available only for mongod.

replication.replSetName

Type: string

The name of the replica set that the mongod is part of. All hosts in the replica set must have the same set name.

If your application connects to more than one replica set, each set should have a distinct name. Some drivers group replica set connections by replica set name.

The replication.replSetName setting is available only for mongod.

Starting in MongoDB 4.0:

• The setting replication.replSetName cannot be used in conjunction with storage.indexBuildRetry.
• For the WiredTiger storage engine, storage.journal.enabled: false cannot be used in conjunction with replication.replSetName.

replication.enableMajorityReadConcern

Default: true

Starting in MongoDB 3.6, MongoDB enables support for "majority" read concern by default.

You can disable read concern "majority" to prevent the storage cache pressure from immobilizing a deployment with a three-member primary-secondary-arbiter (PSA) architecture. For more information about disabling read concern "majority", see Disable Read Concern Majority.

To disable, set replication.enableMajorityReadConcern to false. replication.enableMajorityReadConcern has no effect for MongoDB versions: 4.0.0, 4.0.1, 4.0.2, 3.6.0.

Important

In general, avoid disabling "majority" read concern unless necessary. However, if you have a three-member replica set with a primary-secondary-arbiter (PSA) architecture or a sharded cluster with a three-member PSA shards, disable to prevent the storage cache pressure from immobilizing the deployment.

Disabling "majority" read concern affects support for transactions on sharded clusters. Specifically:

• A transaction cannot use read concern "snapshot" if the transaction involves a shard that has disabled read concern “majority”.
• A transaction that writes to multiple shards errors if any of the transaction’s read or write operations involves a shard that has disabled read concern "majority".

However, it does not affect transactions on replica sets. For transactions on replica sets, you can specify read concern "majority" (or "snapshot" or "local" ) for multi-document transactions even if read concern "majority" is disabled.

Disabling "majority" read concern prevents collMod commands which modify an index from rolling back. If such an operation needs to be rolled back, you must resync the affected nodes with the primary node.

Disabling "majority" read concern disables support for Change Streams for MongoDB 4.0 and earlier. For MongoDB 4.2+, disabling read concern "majority" has no effect on change streams availability.

sharding Options

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sharding:
   clusterRole: <string>
   archiveMovedChunks: <boolean>

sharding.clusterRole

Type: string

The role that the mongod instance has in the sharded cluster. Set this setting to one of the following:

Value	Description
configsvr	Start this instance as a config server. The instance starts on port 27019 by default.
shardsvr	Start this instance as a shard. The instance starts on port 27018 by default.

Note

Setting sharding.clusterRole requires the mongod instance to be running with replication. To deploy the instance as a replica set member, use the replSetName setting and specify the name of the replica set.

The sharding.clusterRole setting is available only for mongod.

sharding.archiveMovedChunks

Type: boolean

Changed in version 3.2: Starting in 3.2, MongoDB uses false as the default.

During chunk migration, a shard does not save documents migrated from the shard.

auditLog Options

Note

Available only in MongoDB Enterprise and MongoDB Atlas.

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auditLog:
   destination: <string>
   format: <string>
   path: <string>
   filter: <string>

auditLog.destination

Type: string

When set, auditLog.destination enables auditing and specifies where mongos or mongod sends all audit events.

auditLog.destination can have one of the following values:

Value	Description
syslog	Output the audit events to syslog in JSON format. Not available on Windows. Audit messages have a syslog severity level of info and a facility level of user. The syslog message limit can result in the truncation of audit messages. The auditing system will neither detect the truncation nor error upon its occurrence.
console	Output the audit events to stdout in JSON format.
file	Output the audit events to the file specified in auditLog.path in the format specified in auditLog.format.

Note

Available only in MongoDB Enterprise and MongoDB Atlas.

auditLog.format

Type: string

The format of the output file for auditing if destination is file. The auditLog.format option can have one of the following values:

Value	Description
JSON	Output the audit events in JSON format to the file specified in auditLog.path.
BSON	Output the audit events in BSON binary format to the file specified in auditLog.path.

Printing audit events to a file in JSON format degrades server performance more than printing to a file in BSON format.

Note

Available only in MongoDB Enterprise and MongoDB Atlas.

auditLog.path

Type: string

The output file for auditing if destination has value of file. The auditLog.path option can take either a full path name or a relative path name.

Note

Available only in MongoDB Enterprise and MongoDB Atlas.

auditLog.filter

Type: string representation of a document

The filter to limit the types of operations the audit system records. The option takes a string representation of a query document of the form:

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{ <field1>: <expression1>, ... }

The <field> can be any field in the audit message, including fields returned in the param document. The <expression> is a query condition expression.

To specify an audit filter, enclose the filter document in single quotes to pass the document as a string.

To specify the audit filter in a configuration file, you must use the YAML format of the configuration file.

Note

Available only in MongoDB Enterprise and MongoDB Atlas.

snmp Options

Note

MongoDB Enterprise on macOS does not include support for SNMP due to SERVER-29352.

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snmp:
   disabled: <boolean>
   subagent: <boolean>
   master: <boolean>

snmp.disabled

Type: boolean

Default: false

Disables SNMP access to mongod. The option is incompatible with snmp.subagent and snmp.master.

Set to true to disable SNMP access.

The snmp.disabled setting is available only for mongod.

New in version 4.0.6.

snmp.subagent

Type: boolean

When snmp.subagent is true, SNMP runs as a subagent. The option is incompatible with snmp.disabled set to true.

The snmp.subagent setting is available only for mongod.

snmp.master

Type: boolean

When snmp.master is true, SNMP runs as a master. The option is incompatible with snmp.disabled set to true.

The snmp.master setting is available only for mongod.

See also

• Monitor MongoDB With SNMP on Linux
• Monitor MongoDB Windows with SNMP
• Troubleshoot SNMP

mongos-only Options

Changed in version 3.4: MongoDB 3.4 removes sharding.chunkSize and sharding.autoSplit settings.

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replication:
   localPingThresholdMs: <int>

sharding:
   configDB: <string>

replication.localPingThresholdMs

Type: integer

Default: 15

The ping time, in milliseconds, that mongos uses to determine which secondary replica set members to pass read operations from clients. The default value of 15 corresponds to the default value in all of the client drivers.

When mongos receives a request that permits reads to secondary members, the mongos will:

• Find the member of the set with the lowest ping time.

• Construct a list of replica set members that is within a ping time of 15 milliseconds of the nearest suitable member of the set.

  If you specify a value for the replication.localPingThresholdMs option, mongos will construct the list of replica members that are within the latency allowed by this value.

• Select a member to read from at random from this list.

The ping time used for a member compared by the replication.localPingThresholdMs setting is a moving average of recent ping times, calculated at most every 10 seconds. As a result, some queries may reach members above the threshold until the mongos recalculates the average.

See the Read Preference for Replica Sets section of the read preference documentation for more information.

sharding.configDB

Type: string

Changed in version 3.2.

The configuration servers for the sharded cluster.

Starting in MongoDB 3.2, config servers for sharded clusters can be deployed as a replica set. The replica set config servers must run the WiredTiger storage engine. MongoDB 3.2 deprecates the use of three mirrored mongod instances for config servers.

Specify the config server replica set name and the hostname and port of at least one of the members of the config server replica set.

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sharding:
  configDB: <configReplSetName>/cfg1.example.net:27019, cfg2.example.net:27019,...

The mongos instances for the sharded cluster must specify the same config server replica set name but can specify hostname and port of different members of the replica set.

Windows Service Options

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processManagement:
   windowsService:
      serviceName: <string>
      displayName: <string>
      description: <string>
      serviceUser: <string>
      servicePassword: <string>

processManagement.windowsService.serviceName

Type: string

Default: MongoDB

The service name of mongos or mongod when running as a Windows Service. Use this name with the net start <name> and net stop <name> operations.

You must use processManagement.windowsService.serviceName in conjunction with either the --install or --remove option.

processManagement.windowsService.displayName

Type: string

Default: MongoDB

The name listed for MongoDB on the Services administrative application.

processManagement.windowsService.description

Type: string

Default: MongoDB Server

Run mongos or mongod service description.

You must use processManagement.windowsService.description in conjunction with the --install option.

For descriptions that contain spaces, you must enclose the description in quotes.

processManagement.windowsService.serviceUser

Type: string

The mongos or mongod service in the context of a certain user. This user must have “Log on as a service” privileges.

You must use processManagement.windowsService.serviceUser in conjunction with the --install option.

processManagement.windowsService.servicePassword

Type: string

The password for <user> for mongos or mongod when running with the processManagement.windowsService.serviceUser option.

You must use processManagement.windowsService.servicePassword in conjunction with the --install option.

Removed MMAPv1 Options

Starting in version 4.2, MongoDB removes the deprecated MMAPv1 storage engine and the MMAPv1-specific configuration options:

Removed Configuration File Setting	Removed Command-line Option
storage.mmapv1.journal.commitIntervalMs
storage.mmapv1.journal.debugFlags	mongod --journalOptions
storage.mmapv1.nsSize	mongod --nssize
storage.mmapv1.preallocDataFiles	mongod --noprealloc
storage.mmapv1.quota.enforced	mongod --quota
storage.mmapv1.quota.maxFilesPerDB	mongod --quotaFiles
storage.mmapv1.smallFiles	mongod --smallfiles
storage.repairPath	mongod --repairpath
replication.secondaryIndexPrefetch	mongod --replIndexPrefetch

For earlier versions of MongoDB, refer to the corresponding version of the manual. For example:

• https://docs.mongodb.com/v4.0
• https://docs.mongodb.com/v3.6
• https://docs.mongodb.com/v3.4

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