Self-Managed Configuration File Options

Externally Sourced Values

The following expansion directives are available:

For complete documentation, see Externally Sourced Configuration File Values for Self-Managed Deployments.

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:

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 for Self-Managed Deployments.

systemLog.component Options

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>

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

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

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

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

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

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

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

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.

net.unixDomainSocket Options

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.tls Options

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>
      logVersions: <string>

net.tls.mode

Type: string

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, you must set the tlsUseSystemCA parameter to true. This makes MongoDB use the system-wide CA certificate store when connecting to a 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

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

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 does 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

The password to de-crypt the certificate-key file (i.e. certificateKeyFile). Use the net.tls.certificateKeyFilePassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod redacts the password from all logging and reporting output.

On Linux/BSD, if the private key in the PEM file is encrypted and you do not specify the net.tls.certificateKeyFilePassword option, MongoDB prompts for a passphrase.

For more information, 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

Specifies a certificate property in order to select a matching certificate from the operating system's certificate store to use for TLS/SSL. Available on Windows and macOS as an alternative to net.tls.certificateKeyFile.

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.

Warning

If you use net.tls.certificateSelector and/or net.tls.clusterCertificateSelector, we do not recommend using 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.

Note

You cannot use the rotateCertificates command or the db.rotateCertificates() shell method when using net.tls.certificateSelector or --tlsCertificateSelector set to thumbprint

net.tls.clusterCertificateSelector

Type: string

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.

Available on Windows and macOS as an alternative to net.tls.clusterFile.

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.

Warning

If you use net.tls.certificateSelector and/or net.tls.clusterCertificateSelector, we do not recommend using 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.

mongod / mongos logs a warning on connection if the presented x.509 certificate expires within 30 days of the mongod/mongos host system time.

net.tls.clusterFile

Type: string

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

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.

mongod / mongos logs a warning on connection if the presented x.509 certificate expires within 30 days of the mongod/mongos host system time.

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 does 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

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, mongos or mongod redacts the password from all logging and reporting output.

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 prompts for a passphrase.

For more information, 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

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

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.

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

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

Note

• 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.tls.certificateSelector to use the system SSL certificate store.

• 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

Default: false

If false, all clients must provide client TLS certificates. If true, clients don't need to provide client certificates, but mongod or mongos encrypts the TLS/SSL connection.

If a client provides a client certificate, regardless of what value you set for net.tls.allowConnectionsWithoutCertificates, mongos or mongod performs certificate validation using the root certificate chain specified by CAFile, or the system CA store if tlsUseSystemCA is true, and rejects 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

Default: false

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 Self-Managed Internal/Membership Authentication.

net.tls.allowInvalidHostnames

Type: boolean

Default: false

When net.tls.allowInvalidHostnames is true, MongoDB disables the validation of the hostnames in TLS certificates. This allows mongod or mongos to connect to other MongoDB instances in the cluster, even if the hostname of their certificates does not match the specified hostname.

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

net.tls.disabledProtocols

Type: string

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, but do not use spaces after the commas. If you include a space before a protocol name, the server interprets it as an unrecognized protocol and doesn't start.

net.tls.disabledProtocols recognizes the following protocols: TLS1_0, TLS1_1, TLS1_2, and 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 without spaces after the commas. For example TLS1_0,TLS1_1.

• Specifying an unrecognized protocol or including a space after a comma prevents the server from starting.

• The specified disabled protocols overrides any default disabled protocols.

MongoDB disables the use of TLS 1.0 if TLS 1.1+ is available on the system. To enable TLS 1.0, specify none to net.tls.disabledProtocols.

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

Tip

See also:

Disallow Protocols

net.tls.FIPSMode

Type: boolean

Default: false

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.tls.logVersions

Type: string

Instructs mongos or mongod to log a message when a client connects using a specified TLS version.

Specify either a single TLS version or a comma-separated list of multiple TLS versions.

Example

To instruct mongos or mongod to log a message when a client connects using either TLS 1.2 or TLS 1.3, set net.tls.logVersions to "TLS1_2,TLS1_3".

net.compression Option

net:
   compression:
      compressors: <string>

net.compression.compressors

Default: snappy,zstd,zlib

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

• mongosh

• drivers that support the OP_COMPRESSED message format.

MongoDB supports the following compressors:

• snappy

• zlib

• zstd

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 mongosh specifies the following network compressors zlib,snappy and the mongod specifies snappy,zlib, messages between mongosh and mongod uses zlib.

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

Key Management Configuration Options

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>
      activateKeys: <boolean>
      keyStatePollingSeconds: <int>

security.enableEncryption

Type: boolean

Default: false

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

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.encryptionCipherMode

Type: string

Default: AES256-CBC

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. MongoDB Enterprise on Windows no longer supports AES256-GCM as a block cipher for encryption at rest. This usage is only supported on Linux.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.encryptionKeyFile

Type: string

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

Requires security.enableEncryption to be true.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.keyIdentifier

Type: string

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 requests 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 throws an error.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.rotateMasterKey

Type: boolean

Default: false

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

Note

Enterprise Feature

Available in MongoDB Enterprise only.

Tip

See also:

KMIP Master Key Rotation

security.kmip.serverName

Type: string

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

You can specify multiple KMIP servers as a comma-separated list, for example server1.example.com,server2.example.com. On startup, the mongod attempts to establish a connection to each server in the order listed, and selects the first server to which it can successfully establish a connection. KMIP server selection occurs only at startup.

mongod verifies the connection to the KMIP server on startup.

The server name specified in --kmipServerName must match either the Subject Alternative Name SAN or the Common Name CN on the certificate presented by the KMIP server. SAN can be a system name or an IP address.

If SAN is present, mongod does not try to match against CN.

If the hostname or IP address of the KMIP server does does not match either SAN or CN, mongod does not start.

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.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.port

Type: string

Default: 5696

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 uses the port specified with security.kmip.port for all provided KMIP servers.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.clientCertificateFile

Type: string

Path to the .pem file used to authenticate MongoDB to the KMIP server. The specified .pem file must contain both the TLS/SSL certificate and key.

To use this setting, you must also specify the security.kmip.serverName setting.

Note

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.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.clientCertificatePassword

Type: string

The password to decrypt the Private Key of the Client Certificate that connects to the KMIP server. This option authenticates MongoDB to the KMIP server and requires that you provide a --kmipClientCertificateFile.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.clientCertificateSelector

Type: string

New in version 5.0: 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.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.serverCAFile

Type: string

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

Note

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.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.connectRetries

Type: int

Default: 0

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.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.connectTimeoutMS

Type: int

Default: 5000

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

Value must be 1000 or greater.

Note

Enterprise Feature

Available in MongoDB Enterprise only.

security.kmip.activateKeys

Type: boolean

Default: true

New in version 5.3.

Activates all newly created KMIP keys upon creation and then periodically checks those keys are in an active state.

When security.kmip.activateKeys is true and you have existing keys on a KMIP server, the key must be activated first or the mongod node fails to start.

If the key being used by the mongod transitions into a non-active state, the mongod node shuts down unless kmipActivateKeys is false. To ensure you have an active key, rotate the KMIP master key by using security.kmip.rotateMasterKey.

security.kmip.keyStatePollingSeconds

Type: int

Default: 900 seconds

New in version 5.3.

Frequency in seconds at which mongod polls the KMIP server for active keys.

To disable disable polling, set the value to -1.

security.sasl Options

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.

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 mongosh 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

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

security.ldap.servers

Type: string

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

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 does 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 useOSDefaults instead of queryUser and queryPassword. You cannot specify both queryUser and useOSDefaults at the same time.

security.ldap.bind.queryPassword

Type: string or array

Available in MongoDB Enterprise only.

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

If not set, mongod or mongos does not attempt to bind to the LDAP server.

You can configure this setting on a running mongod or mongos using setParameter.

The ldapQueryPassword setParameter command accepts either a string or an array of strings. If ldapQueryPassword is set to an array, MongoDB tries each password in order until one succeeds. Use a password array to roll over the LDAP account password without downtime.

Note

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

security.ldap.bind.useOSDefaults

Type: boolean

Default: false

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

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

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 on Self-Managed Deployments, 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

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, through 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

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

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 (for example, 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:

{
  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 through 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 through 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.

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.

Starting in MongoDB 5.0, userToDNMapping accepts an empty string "" or empty array [ ] in place of a mapping document. If providing an empty string or empty array to userToDNMapping, MongoDB maps the authenticated username as the LDAP DN. Previously, providing an empty mapping document would cause mapping to fail.

Example

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

Important

You must pass the array to userToDNMapping as a string.

"[
   {
      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

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.

Note

For better performance, consider placing the LDAP groups used for MongoDB authorization into their own Organizational Unit (OU).

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.

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

[ 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.

"{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.

LDAP Parameters

setParameter.ldapUserCacheInvalidationInterval

Type: int

Default: 30

For use with mongod servers using LDAP Authorization on Self-Managed Deployments.

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.

setParameter:
   ldapUserCacheInvalidationInterval: <int>

storage.wiredTiger Options

storage:
   wiredTiger:
      engineConfig:
         cacheSizeGB: <number>
         journalCompressor: <string>
         directoryForIndexes: <boolean>
         maxCacheOverflowFileSizeGB: <number>
      collectionConfig:
         blockCompressor: <string>
      indexConfig:
         prefixCompression: <boolean>

storage.wiredTiger.engineConfig.cacheSizeGB

Type: float

Defines the maximum size of the internal cache that WiredTiger uses 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.

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 uses 1.5GB of RAM (0.5 * (4 GB - 1 GB) = 1.5 GB). Conversely, on a system with a total of 1.25 GB of RAM WiredTiger allocates 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.

With 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 uses the available free memory for filesystem cache, which allows the compressed MongoDB data files to stay in memory. In addition, the operating system uses 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 (for example, 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

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.zstdCompressionLevel

Type: integer

Default: 6

Specifies the level of compression applied when using the zstd compressor.

Values can range from 1 to 22.

The higher the specified value for zstdCompressionLevel the higher the compression which is applied.

Only applicable when blockCompressor is set to zstd.

Available starting in MongoDB 5.0

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

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 uses the specified compressor. Existing collections 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 uses prefix compression. Existing indexes are not affected.

storage.inmemory Options

storage:
   inMemory:
      engineConfig:
         inMemorySizeGB: <number>

storage.inMemory.engineConfig.inMemorySizeGB

Type: float

Default: 50% of physical RAM less 1 GB

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.

Note

Enterprise Feature

Available in MongoDB Enterprise only.