mongod (original) (raw)
mongod
is the primary daemon process for the MongoDB system. It handles data requests, manages data access, and performs background management operations.
This document provides a complete overview of all command line options for mongod
. These command line options are primarily useful for testing: In common operation, use the configuration file options to control the behavior of your database.
See also:
Note
MongoDB disables support for TLS 1.0 encryption on systems where TLS 1.1+ is available.
Deployments hosted in the following environments use mongod
:
- MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
Note
MongoDB Atlas manages the mongod
for all MongoDB Atlas deployments.
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
mongod includes a Full Time Diagnostic Data Capture mechanism to assist MongoDB engineers with troubleshooting deployments. If this thread fails, it terminates the originating process. To avoid the most common failures, confirm that the user running the process has permissions to create the FTDC
diagnostic.data
directory. Formongod
the directory is withinstorage.dbPath. Formongos
it is parallel to systemLog.path.
Changed in version 6.1:
- MongoDB always enables journaling. As a result, MongoDB removes the
storage.journal.enabled
option and the corresponding--journal
and--nojournal
command-line options.
Changed in version 5.2:
- MongoDB removes the
--cpu
command-line option.
Changed in version 5.0:
- MongoDB removes the
--serviceExecutor
command-line option and the correspondingnet.serviceExecutor
configuration option.
--help, -h
Returns information on the options and use of mongod
.
--version
Returns the mongod
release number.
--config <filename>, -f <filename>
Specifies a configuration file for runtime configuration options. The configuration file is the preferred method for runtime configuration ofmongod
. The options are equivalent to the command-line configuration options. See Self-Managed Configuration File Options for more information.
Ensure the configuration file uses ASCII encoding. The mongod
instance does not support configuration files with non-ASCII encoding, including UTF-8.
--configExpand <none|rest|exec>
Default: none
Enables using Expansion Directivesin configuration files. Expansion directives allow you to set externally sourced values for configuration file options.
--configExpand supports the following expansion directives:
Value | Description |
---|---|
none | Default. mongod does not expand expansion directives.mongod fails to start if any configuration file settings use expansion directives. |
rest | mongod expands __rest expansion directives when parsing the configuration file. |
exec | mongod expands __exec expansion directives when parsing the configuration file. |
You can specify multiple expansion directives as a comma-separated list, for example: rest, exec
. If the configuration file contains expansion directives not specified to --configExpand, the mongod
returns an error and terminates.
See Externally Sourced Configuration File Values for Self-Managed Deployments for configuration files for more information on expansion directives.
--verbose, -v
Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the -v
form by including the option multiple times, for example: -vvvvv
.
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.
--quiet
Runs mongod
in a quiet mode that attempts to limit the amount of output.
This option suppresses:
- output from database commands
- replication activity
- connection accepted events
- connection closed events
--port <port>
Default:
- 27017 if
mongod
is not a shard member or a config server member - 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.
The --port
option accepts a range of values between 0
and 65535
. Setting the port to 0
configures mongod
to use an arbitrary port assigned by the operating system.
--bind_ip <hostnames|ipaddresses|Unix domain socket paths>
Default: localhost
The hostnames and/or IP addresses and/or full Unix domain socket paths on which mongod
should listen for client connections. You may attach 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 --bind_ip, you must start mongod
with--ipv6 to enable IPv6 support. Specifying an IPv6 address to --bind_ip does not enable IPv6 support.
If specifying alink-local IPv6 address(fe80::/10
), you must append thezone indexto that address (i.e. fe80::<address>%<adapter-name>
).
Example
localhost,fe80::a00:27ff:fee0:1fcf%enp0s3
Important
To avoid configuration updates due to IP address changes, use DNS hostnames instead of IP addresses. It is particularly important to use a DNS hostname instead of an IP address when configuring replica set members or sharded cluster members.
Use hostnames instead of IP addresses to configure clusters across a split network horizon. Starting in MongoDB 5.0, nodes that are only configured with an IP address fail startup validation and do not start.
Warning
For more information about IP Binding, refer to theIP Binding in Self-Managed Deployments 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 an asterisk "*"
(enclose the asterisk in quotes to avoid filename pattern expansion). Alternatively, use the net.bindIpAll setting.
Note
--bind_ip
and--bind_ip_all
are mutually exclusive. Specifying both options causesmongod
to throw an error and terminate.- The command-line option
--bind
overrides the configuration file setting net.bindIp.
--bind_ip_all
If specified, the mongod
instance binds to all IPv4 addresses (i.e. 0.0.0.0
). If mongod
starts with--ipv6, --bind_ip_all also binds to all IPv6 addresses (i.e. ::
).
mongod
only supports IPv6 if started with --ipv6. Specifying--bind_ip_all alone does not enable IPv6 support.
Warning
For more information about IP Binding, refer to theIP Binding in Self-Managed Deployments documentation.
Alternatively, you can set the --bind_ip
option to ::,0.0.0.0
or to an asterisk "*"
(enclose the asterisk in quotes to avoid filename pattern expansion).
Note
--bind_ip
and --bind_ip_all
are mutually exclusive. That is, you can specify one or the other, but not both.
--clusterIpSourceAllowlist <string>
New in version 5.0.
A list of IP addresses/CIDR (Classless Inter-Domain Routing) ranges against which themongod
validates authentication requests from other members of the replica set and, if part of a sharded cluster, the mongosinstances. 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 themongod
or mongos.
--clusterIpSourceAllowlist has no effect on a mongod
started withoutauthentication.
--clusterIpSourceAllowlist accepts multiple comma-separated IPv4/6 addresses or Classless Inter-Domain Routing (CIDR) ranges:
mongod --clusterIpSourceAllowlist 192.0.2.0/24,127.0.0.1,::1
Important
Ensure --clusterIpSourceAllowlist 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.
--ipv6
Enables IPv6 support. mongod
disables IPv6 support by default.
Setting --ipv6 does not direct the mongod
to listen on any local IPv6 addresses or interfaces. To configure the mongod
to listen on an IPv6 interface, you must either:
- Configure --bind_ip with one or more IPv6 addresses or hostnames that resolve to IPv6 addresses, or
- Set --bind_ip_all to
true
.
--listenBacklog <number>
Default: Target system SOMAXCONN
constant
The maximum number of connections that can exist in the listen queue.
Warning
Consult your local system's documentation to understand the limitations and configuration requirements before using this parameter.
Important
To prevent undefined behavior, specify a value for this parameter between 1
and the local system SOMAXCONN
constant.
The default value for the listenBacklog
parameter is set at compile time to the target system SOMAXCONN
constant.SOMAXCONN
is the maximum valid value that is documented for the backlog parameter to the listen system call.
Some systems may interpret SOMAXCONN
symbolically, and others numerically. The actual listen backlog applied in practice may differ from any numeric interpretation of the SOMAXCONN
constant or argument to --listenBacklog
, and may also be constrained by system settings like net.core.somaxconn
on Linux.
Passing a value for the listenBacklog
parameter that exceeds theSOMAXCONN
constant for the local system is, by the letter of the standards, undefined behavior. Higher values may be silently integer truncated, may be ignored, may cause unexpected resource consumption, or have other adverse consequences.
On systems with workloads that exhibit connection spikes, for which it is empirically known that the local system can honor higher values for the backlog parameter than the SOMAXCONN
constant, setting the listenBacklog
parameter to a higher value may reduce operation latency as observed by the client by reducing the number of connections which are forced into a backoff state.
--maxConns <number>
The maximum number of simultaneous connections that mongod
accepts. 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.
--logpath <path>
Sends all diagnostic logging information to a log file instead of to standard output or to the host's syslog system. MongoDB creates the log file at the path you specify.
By default, MongoDB moves any existing log file rather than overwriting it. To instead append to the log file, set the --logappend option.
--syslog
Sends all logging output to the host's syslog system rather than to standard output or to a log file (--logpath).
The --syslog option is not supported on Windows.
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 --logpath option for production systems to ensure accurate timestamps.
MongoDB includes the component in its log messages to syslog
.
... ACCESS [repl writer worker 5] Unsupported modification to roles collection ...
--syslogFacility <string>
Default: user
Specifies 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 enable the --syslog option.
--logappend
Appends new entries to the end of the existing log file when the mongod
instance restarts. Without this option, mongod
backs up the existing log and create a new file.
--logRotate <string>
Default: rename
Determines the behavior for the logRotate command when rotating the server log and/or the audit log. Specify eitherrename
or reopen
:
rename
renames the log file.reopen
closes and reopens the log file following the typical Linux/Unix log rotate behavior. Usereopen
when using the Linux/Unix logrotate utility to avoid log loss.
If you specifyreopen
, you must also use --logappend.
--timeStampFormat <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
--timeStampFormat no longer supports ctime
. An example of ctime
formatted date is: Wed Dec 31 18:17:54.811
.
--traceExceptions
For internal diagnostic use only.
--pidfilepath <path>
Specifies a file location to store the process ID (PID) of the mongod
process. The user running the mongod
or mongos
process must be able to write to this path. If the --pidfilepath option is not specified, the process does not create a PID file. This option is generally only useful in combination with the --fork option.
Note
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 --pidfilepath option if you are not using one of these init systems. For more information, please see the respectiveInstallation Guide for your operating system.
Note
macOS
On macOS, PID file management is generally handled by brew
. Only use the --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.
--keyFile <file>
Specifies the path to a key file that stores the shared secret that MongoDB instances use to authenticate to each other in asharded cluster or replica set. --keyFile implies--auth. See Self-Managed Internal/Membership Authentication for more information.
Keyfiles for internal membership authentication use YAML format to allow for multiple keys in a keyfile. The YAML format accepts either:
- A single key string (same as in earlier versions)
- A sequence of key strings
The YAML format is compatible with the existing single-key keyfiles that use the text file format.
--setParameter <options>
Specifies one of the MongoDB parameters described inMongoDB Server Parameters for a Self-Managed Deployment. You can specify multiple setParameter
fields.
--nounixsocket
Disables listening on the UNIX domain socket. --nounixsocket applies only to Unix-based systems.
The mongod
process always listens on the UNIX socket unless one of the following is true:
- --nounixsocket is set
- net.bindIp is not set
- net.bindIp does not specify
localhost
or its associated IP address
mongod
installed from official Install MongoDB Community Edition on Debianand Install MongoDB Community Edition on Red Hat or CentOS packages have the bind_ip
configuration set to 127.0.0.1
by default.
--unixSocketPrefix <path>
Default: /tmp
The path for the UNIX socket. --unixSocketPrefix applies only to Unix-based systems.
If this option has no value, themongod
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
--filePermissions <path>
Default: 0700
Sets the permission for the UNIX domain socket file.
--filePermissions applies only to Unix-based systems.
--fork
Enables a daemon mode that runs the mongod
process in the background. The --fork option is not supported on Windows.
By default mongod
does not run as a daemon. You run mongod
as a daemon by using either --fork or a controlling process that handles daemonization, such as upstart
or systemd
.
To use --fork, configure log output for the mongod
with one of the following:
--auth
Enables authorization to control user's access to database resources and operations. When authorization is enabled, MongoDB requires all clients to authenticate themselves first in order to determine the access for the client.
To configure users, use the mongosh client. If no users exist, the localhost interface has access to the database until you create the first user.
See Security for more information.
--noauth
Disables authentication. Currently the default. Exists for future compatibility and clarity.
--transitionToAuth
Allows the mongod
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--keyFile.
For example, if using keyfiles forinternal authentication, the mongod
creates an authenticated connection with any mongod
or mongosin the deployment using a matching keyfile. If the security mechanisms do not match, the mongod
utilizes a non-authenticated connection instead.
A mongod
running with --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.
--sysinfo
Returns diagnostic system information and then exits. The information provides the page size, the number of physical pages, and the number of available physical pages.
--noscripting
Disables the scripting engine.
--notablescan
Forbids operations that require a collection scan. See notablescan for additional information.
--shutdown
The --shutdown option cleanly and safely terminates the mongod
process. When invoking mongod
with this option you must set the--dbpath option either directly or by way of theconfiguration file and the--config option.
The --shutdown option is available only on Linux systems.
For additional ways to shut down, see also Stop mongod Processes.
--redactClientLogData
Available in MongoDB Enterprise only.
A mongod
running with --redactClientLogData redacts any message accompanying a given log event before logging. This prevents the mongod
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 --redactClientLogData in conjunction withEncryption at Rest andTLS/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
logs events such as those related to CRUD operations, sharding metadata, etc. It is possible that the mongod
may expose PII as a part of these logging operations. A mongod
running with --redactClientLogData removes any message accompanying these events before being output to the log, effectively removing the PII.
Diagnostics on a mongod
running with --redactClientLogData may be more difficult due to the lack of data related to a log event. See theprocess logging manual page for an example of the effect of --redactClientLogData on log output.
On a running mongod
, use setParameter with theredactClientLogData parameter to configure this setting.
--networkMessageCompressors <string>
Default: snappy,zstd,zlib
Specifies the default compressor(s) to use for communication between this mongod
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:
Note
Both mongod
and mongos instances default tosnappy,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 mongosh specifies the following network compressors zlib,snappy
and the mongod specifiessnappy,zlib
, messages between mongosh andmongod uses zlib
.
If the parties do not share at least one common compressor, messages between the parties are uncompressed. For example, ifmongosh specifies the network compressorzlib
and mongod specifies snappy
, messages between mongosh and mongod are not compressed.
--timeZoneInfo <path>
The full path from which to load the time zone database. If this option is not provided, then MongoDB uses 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 time zone database release cycle differs from the MongoDB release cycle. The most recent release of the time zone database is available on our download site.
wget https://downloads.mongodb.org/olson_tz_db/timezonedb-latest.zip
unzip timezonedb-latest.zip
mongod --timeZoneInfo timezonedb-2017b/
Warning
MongoDB uses the third party timelib library to provide accurate conversions between timezones. Due to a recent update, timelib
could create inaccurate time zone conversions in older versions of MongoDB.
To explicitly link to the time zone database in versions of MongoDB prior to 5.0, download the time zone database. and use the timeZoneInfo parameter.
See also:
--outputConfig
Outputs the mongod
instance's configuration options, formatted in YAML, to stdout
and exits the mongod
instance. For configuration options that uses Externally Sourced Configuration File Values for Self-Managed Deployments,--outputConfig returns the resolved value for those options.
Warning
This may include any configured passwords or secrets previously obfuscated through the external source.
For usage examples, see:
- Output the Configuration File with Resolved Expansion Directive Values
- Convert Self-Managed Command-Line Options to YAML
Note
Starting in MongoDB 8.0, LDAP authentication and authorization is deprecated. LDAP is available and will continue to operate without changes throughout the lifetime of MongoDB 8. LDAP will be removed in a future major release.
For details, see LDAP Deprecation.
--ldapServers <host1>:<port>,<host2>:<port>,...,<hostN>:<port>
Available in MongoDB Enterprise only.
The LDAP server against which the mongod
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--ldapServers. MongoDB supports following LDAP referrals as defined in RFC 4511 4.1.10. Do not use --ldapServersfor listing every LDAP server in your infrastructure.
This setting can be configured on a running mongod
usingsetParameter.
If unset, mongod
cannot use LDAP authentication or authorization.
--ldapValidateLDAPServerConfig <boolean>
Available in MongoDB Enterprise
A flag that determines if the mongod
instance checks the availability of the LDAP server(s) as part of its startup:
- If
true
, themongod
instance performs the availability check and only continues to start up if the LDAP server is available. - If
false
, themongod
instance skips the availability check; i.e. the instance starts up even if the LDAP server is unavailable.
--ldapQueryUser <string>
Available in MongoDB Enterprise only.
The identity with which mongod
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 username transformation.
- The LDAP server disallows anonymous binds
You must use --ldapQueryUser with --ldapQueryPassword.
If unset, mongod
doesn't attempt to bind to the LDAP server.
This setting can be configured on a running mongod
usingsetParameter.
Note
Windows MongoDB deployments can use --ldapBindWithOSDefaultsinstead of --ldapQueryUser and --ldapQueryPassword. You cannot specify both --ldapQueryUser and --ldapBindWithOSDefaults at the same time.
--ldapQueryPassword <string | array>
Available in MongoDB Enterprise only.
The password used to bind to an LDAP server when using--ldapQueryUser. You must use --ldapQueryPassword with--ldapQueryUser.
If not set, mongod does not attempt to bind to the LDAP server.
You can configure this setting on a running mongod usingsetParameter.
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 --ldapBindWithOSDefaultsinstead of --ldapQueryUser and --ldapQueryPassword. You cannot specify both --ldapQueryPassword and--ldapBindWithOSDefaults at the same time.
--ldapBindWithOSDefaults <bool>
Default: false
Available in MongoDB Enterprise for the Windows platform only.
Allows mongod
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 --ldapBindWithOSDefaults to replace --ldapQueryUser and--ldapQueryPassword.
--ldapBindMethod <string>
Default: simple
Available in MongoDB Enterprise only.
The method mongod
uses to authenticate to an LDAP server. Use with --ldapQueryUser and --ldapQueryPassword to connect to the LDAP server.
--ldapBindMethod supports the following values:
simple
-mongod
uses simple authentication.sasl
-mongod
uses SASL protocol for authentication
If you specify sasl
, you can configure the available SASL mechanisms using --ldapBindSaslMechanisms. mongod
defaults to using DIGEST-MD5
mechanism.
--ldapBindSaslMechanisms <string>
Default: DIGEST-MD5
Available in MongoDB Enterprise only.
A comma-separated list of SASL mechanisms mongod
can use when authenticating to the LDAP server. The mongod
and the LDAP server must agree on at least one mechanism. The mongod
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
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 withKerberos Authentication on Self-Managed Deployments, verify the following for themongod
host machine:
Linux
- The
KRB5_CLIENT_KTNAME
environment variable resolves to the name of the client Linux Keytab Filesfor the host machine. For more on Kerberos environment variables, please defer to theKerberos documentation. - The client keytab includes aUser Principal for the
mongod
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 aTicket-Granting-Ticketwhen the user logs onto the system. Set --ldapBindWithOSDefaults totrue
to allow mongod
to use the generated credentials when connecting to the Active Directory server and execute queries.
Set --ldapBindMethod to sasl
to use this option.
Note
For a complete list of SASL mechanisms see theIANA 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.
--ldapTransportSecurity <string>
Default: tls
Available in MongoDB Enterprise only.
By default, mongod
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 thelibldap
dependency. See the documentation for TLS Options
in theldap.conf OpenLDAP documentationfor 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 --ldapTransportSecurity to none
to disable TLS/SSL between mongod
and the LDAP server.
Warning
Setting --ldapTransportSecurity to none
transmits plaintext information and possibly credentials between mongod
and the LDAP server.
--ldapTimeoutMS <int>
Default: 10000
Available in MongoDB Enterprise only.
The amount of time in milliseconds mongod
should wait for an LDAP server to respond to a request.
Increasing the value of --ldapTimeoutMS 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 --ldapTimeoutMS reduces the time MongoDB waits for a response from the LDAP server.
This setting can be configured on a running mongod
usingsetParameter.
--ldapRetryCount <int>
New in version 6.1.
Default: 0
Available in MongoDB Enterprise only.
Number of operation retries by the server LDAP manager after a network error.
--ldapUserToDNMapping <string>
Available in MongoDB Enterprise only.
Maps the username provided to mongod
for authentication to a LDAP Distinguished Name (DN). You may need to use --ldapUserToDNMapping 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, such as x.509 or kerberos, to a full LDAP DN for authorization.
--ldapUserToDNMapping 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 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 executes the query against the LDAP server to retrieve the LDAP DN for the authenticated user. mongod requires exactly one returned result for the transformation to be successful, or mongod 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
orldapQuery
. You cannot specify both in the same document.
When performing authentication or authorization, mongod
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
applies the transformation and uses the output for authenticating the user. mongod
does not check the remaining documents in the array.
If the given document does not match the provided authentication name, mongod
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
returns an error.
mongod
also returns an error if one of the transformations cannot be evaluated due to networking or authentication failures to the LDAP server.mongod
rejects the connection request and does not check the remaining documents in the array.
Starting in MongoDB 5.0, --ldapUserToDNMappingaccepts an empty string ""
or empty array [ ]
in place of a mapping documnent. If providing an empty string or empty array to--ldapUserToDNMapping, MongoDB maps the authenticated username as the LDAP DN. In earlier versions, providing an empty mapping document causes mapping to fail.
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 --ldapUserToDNMapping 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 stringalice
. 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
executes this query against the LDAP server, returning the result"cn=bob,ou=dba,dc=example,dc=com"
.
If --ldapUserToDNMapping is unset, mongod
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
using thesetParameter database command.
--ldapAuthzQueryTemplate <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 --ldapServers.
In the URL, you can use the following substituion tokens:
Substitution Token | Description |
---|---|
{USER} | Substitutes the authenticated username, or thetransformedusername if a username mapping 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 the DNs which this entity is 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 theadmin
database exactly matches the DN, mongod
grants the user the roles and privileges assigned to that role. See thedb.createRole() method for more information on creating roles.
Example
This LDAP query returns any groups listed in the LDAP user object'smemberOf
attribute.
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 thesetParameter 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.
--storageEngine string
Default: wiredTiger
Specifies the storage engine for the mongod
database. Available values include:
If you attempt to start a mongod
with a--dbpath that contains data files produced by a storage engine other than the one specified by--storageEngine, mongod
doesn't start.
--dbpath <path>
Default: /data/db
on Linux and macOS, \data\db
on Windows
The directory where the mongod
instance stores its data.
If using the defaultConfiguration Fileincluded with a package manager installation of MongoDB, the corresponding storage.dbPath setting uses a different default.
The files in --dbpath must correspond to the storage engine specified in --storageEngine. If the data files do not correspond to --storageEngine, mongod
doesn't start.
--directoryperdb
Uses a separate directory to store data for each database. The directories are under the --dbpath directory, and each subdirectory name corresponds to the database name.
Not available for mongod instances that use thein-memory storage engine.
Starting in MongoDB 5.0, dropping the final collection in a database (or dropping the database itself) when --directoryperdb is enabled deletes the newly empty subdirectory for that database.
To change the --directoryperdb option for existing deployments:
- For standalone instances:
- Use mongodump on the existing
mongod
instance to generate a backup. - Stop the
mongod
instance. - Add the --directoryperdb value andconfigure a new data directory
- Restart the
mongod
instance. - Use mongorestore to populate the new data directory.
- Use mongodump on the existing
- For replica sets:
- Stop a secondary member.
- Add the --directoryperdb value andconfigure a new data directory to that secondary member.
- Restart that secondary.
- Use initial sync to populate the new data directory.
- Update remaining secondaries in the same fashion.
- Step down the primary, and update the stepped-down member in the same fashion.
--syncdelay <value>
Default: 60
Controls how much time can pass before MongoDB flushes data to the data files.
Do not set this value on production systems. In almost every situation, you should use the default setting.
The mongod
process writes data very quickly to the journal and lazily to the data files. --syncdelay has no effect onjournaling, but if --syncdelay is set to0
the journal eventually consumes all available disk space.
Not available for mongod instances that use thein-memory storage engine.
To provide durable data, WiredTigeruses checkpoints. For more details, see Journaling and the WiredTiger Storage Engine.
--upgrade
Upgrades the on-disk data format of the files specified by the--dbpath to the latest version, if needed.
This option only affects the operation of the mongod
if the data files are in an old format.
In most cases you should not set this value, so you can exercise the most control over your upgrade process. See the MongoDB release notes for more information about the upgrade process.
--repair
Runs a repair routine on all databases for a mongod
instance.
Starting in MongoDB 5.0:
- The repair operation validates the collections to find any inconsistencies and fixes them if possible, which avoids rebuilding the indexes.
- If a collection's data file is salvaged or if the collection has inconsistencies that the validate step is unable to fix, then all indexes are rebuilt.
Tip
If you are running with journaling enabled, there is almost never any need to run repair since the server can use the journal files to restore the data files to a clean state automatically. However, you may need to run repair in cases where you need to recover from a disk-level data corruption.
Warning
- Only use mongod --repair if you have no other options. The operation removes and does not save any corrupt data during the repair process.
- Avoid running --repair against a replica set member:
- To repair a replica set member, if you have an intact copy of your data available (e.g. a recent backup or an intact member of the replica set), restore from that intact copy instead. To learn more, see Resync a Member of a Self-Managed Replica Set.
- If you choose to run mongod --repair against a replica set member and the operation modifies the data or the metadata, you must still perform a full resync in order for the member to rejoin the replica set.
- Before using --repair, make a backup copy of the dbpath directory.
- If repair fails to complete for any reason, you must restart the instance using the --repair option.
--journalCommitInterval <value>
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. A write that includes or impliesj:true
causes an immediate sync of the journal. For details and additional conditions that affect the frequency of the sync, seeJournaling Process.
Not available for mongod instances that use thein-memory storage engine.
--wiredTigerCacheSizeGB <float>
Defines the maximum size of the internal cache that WiredTiger uses for all data. The memory consumed by an index build (seemaxIndexBuildMemoryUsageMegabytes) 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 --wiredTigerCacheSizeGB 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 mongodinstances.
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 --wiredTigerCacheSizeGB 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. SeememLimitMB.
--wiredTigerJournalCompressor <compressor>
Default: snappy
Specifies the type of compression to use to compress WiredTiger journal data.
Available compressors are:
--wiredTigerDirectoryForIndexes
When you start mongod
with --wiredTigerDirectoryForIndexes, mongod
stores indexes and collections in separate subdirectories under the data (i.e. --dbpath) directory. Specifically, mongod
stores the indexes in a subdirectory namedindex
and the collection data in a subdirectory namedcollection
.
By using a symbolic link, you can specify a different location for the indexes. Specifically, when mongod
instance is notrunning, move the index
subdirectory to the destination and create a symbolic link named index
under the data directory to the new destination.
--wiredTigerCollectionBlockCompressor <compressor>
Default: snappy
Specifies the default compression for collection data. You can override this on a per-collection basis when creating collections.
Available compressors are:
--wiredTigerCollectionBlockCompressor affects all collections created. If you change the value of --wiredTigerCollectionBlockCompressor on an existing MongoDB deployment, all new collections use the specified compressor. Existing collections continue to use the compressor specified when they were created, or the default compressor at that time.
--wiredTigerIndexPrefixCompression <boolean>
Default: true
Enables or disables prefix compression for index data.
Specify true
for --wiredTigerIndexPrefixCompression to enable prefix compression for index data, or false
to disable prefix compression for index data.
The --wiredTigerIndexPrefixCompression setting affects all indexes created. If you change the value of --wiredTigerIndexPrefixCompression on an existing MongoDB deployment, all new indexes use prefix compression. Existing indexes are not affected.
--replSet <setname>
Configures replication. Specify a replica set name as an argument to this set. All hosts in the replica set must have the same set name.
If your application connects to more than one replica set, each set must have a distinct name. Some drivers group replica set connections by replica set name.
--oplogSize <value>
The maximum size in megabytes for the oplog. TheoplogSize
setting configures the uncompressed size of the oplog, not the size on disk.
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 --oplogSize option doesn't affect the size of the oplog. To change the minimum oplog retention period after starting the mongod
, usereplSetResizeOplog. replSetResizeOplogenables you to resize the oplog dynamically without restarting themongod
process. To persist the changes made usingreplSetResizeOplog through a restart, update the value of --oplogSize.
See Oplog Size for more information.
--oplogMinRetentionHours <value>
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. SeeClock Synchronization for more information on clock synchronization across cluster members.
To change the minimum oplog retention period after starting themongod
, use replSetResizeOplog.replSetResizeOplog enables you to resize the oplog dynamically without restarting the mongod
process. To persist the changes made using replSetResizeOplogthrough a restart, update the value of--oplogMinRetentionHours.
--enableMajorityReadConcern
Default: true
Configures support for "majority" read concern.
Starting in MongoDB 5.0,--enableMajorityReadConcern cannot be changed and is always set to true
. In earlier versions of MongoDB,--enableMajorityReadConcern was configurable.
Warning
If you are using a three-member primary-secondary-arbiter (PSA) architecture, consider the following:
- The write concern "majority" can cause performance issues if a secondary is unavailable or lagging. For advice on how to mitigate these issues, seeMitigate Performance Issues with a Self-Managed PSA Replica Set.
- If you are using a global default "majority"and the write concern is less than the size of the majority, your queries may return stale (not fully replicated) data.
--configsvr
Required if starting a config server.
Declares that this mongod
instance serves as the config server of a sharded cluster. When running with this option, clients (i.e. other cluster components) cannot write data to any database other than config
and admin
. The default port for a mongod
with this option is27019
and the default --dbpath directory is/data/configdb
, unless specified.
Important
When starting a MongoDB server with --configsvr
, you must also specify a --replSet.
The use of the deprecated mirrored mongod
instances as config servers (SCCC) is no longer supported.
The replica set config servers (CSRS) must run theWiredTiger storage engine.
The --configsvr option creates a local oplog.
Do not use the --configsvr option with --shardsvr. Config servers cannot be a shard server.
Do not use the --configsvr with theskipShardingConfigurationChecks parameter. That is, if you are temporarily starting the mongod
as a standalone for maintenance operations, include the parameterskipShardingConfigurationChecks and exclude --configsvr. Once maintenance has completed, remove theskipShardingConfigurationChecks parameter and restart with --configsvr.
--shardsvr
Required if starting a shard server.
Configures this mongod
instance as a shard in a sharded cluster. The default port for these instances is27018
.
Important
When starting a MongoDB server with --shardsvr
, you must also specify a --replSet.
Do not use the --shardsvr with theskipShardingConfigurationChecks parameter. That is, if you are temporarily starting the mongod
as a standalone for maintenance operations, include the parameterskipShardingConfigurationChecks and exclude --shardsvr. Once maintenance has completed, remove theskipShardingConfigurationChecks parameter and restart with --shardsvr.
Tip
See:
--tlsMode <mode>
Enables TLS used for all network connections. The argument to the --tlsMode option 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 thetlsUseSystemCA 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, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsCertificateKeyFile <filename>
Specifies the .pem
file that contains both the TLS certificate and key.
On macOS or Windows, you can use the--tlsCertificateSelector option to specify a certificate from the operating system's secure certificate store instead of a PEM key file. --tlsCertificateKeyFile and--tlsCertificateSelector options are mutually exclusive. You can only specify one.
- On Linux/BSD, you must specify --tlsCertificateKeyFilewhen TLS/SSL is enabled.
- On Windows or macOS, you must specify either--tlsCertificateKeyFile or--tlsCertificateSelector when TLS/SSL 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 --tlsCertificateSelector.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsCertificateKeyFilePassword <value>
Specifies the password to decrypt the certificate-key file (i.e.--tlsCertificateKeyFile). Use the--tlsCertificateKeyFilePassword option only if the certificate-key file is encrypted. In all cases, themongod
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 --tlsCertificateKeyFilePassword option, MongoDB prompts 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--tlsCertificateKeyFilePassword option. Alternatively, you can use a certificate from the secure system store (see--tlsCertificateSelector) instead of a 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 --tlsCertificateSelector instead.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--clusterAuthMode <option>
Default: keyFile
The authentication mode used for cluster authentication. If you useinternal 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, you must set thetlsUseSystemCA 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, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsClusterFile <filename>
Specifies 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--tlsClusterCertificateSelector option to specify a certificate from the operating system's secure certificate store instead of a PEM key file. --tlsClusterFile and--tlsClusterCertificateSelector options are mutually exclusive. You can only specify one.
If --tlsClusterFile does not specify the .pem
file for internal cluster authentication or the alternative--tlsClusterCertificateSelector, the cluster uses the.pem
file specified in the --tlsCertificateKeyFileoption or the certificate returned by the--tlsCertificateSelector.
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, seeConfigure mongod and mongos for TLS/SSL andTLS/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 --tlsClusterCertificateSelector.
--tlsCertificateSelector <parameter>=<value>
Note
Available on Windows and macOS as an alternative to--tlsCertificateKeyFile.
Specifies a certificate property in order to select a matching certificate from the operating system's certificate store to use for TLS.
The --tlsCertificateKeyFile and--tlsCertificateSelector options are mutually exclusive. You can only specify one.
--tlsCertificateSelector 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 afingerprint. |
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--tlsCAFile or --tlsClusterCAFile 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.
Note
--tlsClusterCertificateSelector <parameter>=<value>
Note
Available on Windows and macOS as an alternative to--tlsClusterFile.
Specifies a certificate property in order to select a matching certificate from the operating system's certificate store for internal X.509 membership authentication.
--tlsClusterFile and--tlsClusterCertificateSelector options are mutually exclusive. You can only specify one.
--tlsClusterCertificateSelector 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 afingerprint. |
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--tlsCAFile or --tlsClusterCAFile 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.
mongod / mongos logs a warning on connection if the presented X.509 certificate expires within 30
days of the mongod/mongos
host system time.
--tlsClusterPassword <value>
Specifies the password to decrypt the X.509 certificate-key file specified with --tlsClusterFile. Use the--tlsClusterPassword option only if the certificate-key file is encrypted. In all cases, the 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 --tlsClusterPassword option, MongoDB prompts for a passphrase. SeeTLS/SSL Certificate Passphrase.
- On macOS, if the private key in the X.509 file is encrypted, you must explicitly specify the--tlsClusterPassword option. Alternatively, you can either use a certificate from the secure system store (see--tlsClusterCertificateSelector) 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 --tlsClusterCertificateSelector instead.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsCAFile <filename>
Specifies the .pem
file that contains the root certificate chain from the Certificate Authority. Specify the file name of the.pem
file using relative or absolute paths.
Important
When starting a mongod instance withTLS/SSL enabled, you must specify a value for the --tlsCAFile flag, thenet.tls.CAFile configuration option, or the tlsUseSystemCAparameter.
--tlsCAFile
, tls.CAFile
, and tlsUseSystemCA
are all mutually exclusive.
Windows/macOS Only
If using --tlsCertificateSelector and/or--tlsClusterCertificateSelector, do not use--tlsCAFile to specify the root and intermediate CA certificates. Store all CA certificates required to validate the full trust chain of the --tlsCertificateSelector and/or--tlsClusterCertificateSelector certificates in the secure certificate store.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsClusterCAFile <filename>
Specifies 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.--tlsClusterCAFile requires that--tlsCAFile is set.
If --tlsClusterCAFile 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--tlsCAFile option.
--tlsClusterCAFile lets you use separate Certificate Authorities to verify the client to server and server to client portions of the TLS handshake.
Windows/macOS Only
If using --tlsCertificateSelector and/or--tlsClusterCertificateSelector, do not use--tlsClusterCAFile to specify the root and intermediate CA certificates. Store all CA certificates required to validate the full trust chain of the--tlsCertificateSelector and/or--tlsClusterCertificateSelector certificates in the secure certificate store.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsCRLFile <filename>
Specifies 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 a CRL file 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--tlsCertificateSelector 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, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsAllowInvalidCertificates
Bypasses 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 --tlsAllowInvalidCertificates setting, MongoDB logs a warning regarding the use of the invalid certificate.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsAllowInvalidHostnames
Disables the validation of the hostnames in TLS certificates, when connecting to other members of the replica set or sharded cluster for inter-process authentication. This allows mongod
to connect to other members if the hostnames in their certificates do not match their configured hostname.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsAllowConnectionsWithoutCertificates
By default, the server bypasses client certificate validation unless the server is configured to use a CA file. If a CA file is provided, the following rules apply:
- For clients that don't provide certificates, mongod ormongos encrypts the TLS/SSL connection, assuming the connection is successfully made.
- For clients that present a certificate,
mongod
performs certificate validation using the root certificate chain specified by--tlsCAFile and reject clients with invalid certificates.
Use the --tlsAllowConnectionsWithoutCertificates option if you have a mixed deployment that includes clients that do not or cannot present certificates to the mongod
.
For more information about TLS and MongoDB, seeConfigure mongod and mongos for TLS/SSL andTLS/SSL Configuration for Clients .
--tlsDisabledProtocols <protocol(s)>
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.
--tlsDisabledProtocols recognizes the following protocols: TLS1_0
, TLS1_1
,TLS1_2
, and TLS1_3
.
- On macOS, you cannot disable
TLS1_1
and leave bothTLS1_0
andTLS1_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 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 the disabled TLS 1.0, specify none
to --tlsDisabledProtocols.
Members of replica sets and sharded clusters must speak at least one protocol in common.
See also:
--tlsFIPSMode
Directs the mongod
to use the FIPS mode of the TLS library. Your system must have a FIPS compliant library to use the --tlsFIPSMode option.
Note
--profile <level>
Default: 0
Configures the database profiler level. The following profiler levels are available:
0
The profiler is off and does not collect any data. This is the default profiler level.
1
The profiler collects data for operations that exceed theslowms
threshold or match a specified filter.
When a filter is set:
- The
slowms
andsampleRate
options are not used for profiling. - The profiler only captures operations that match thefilter.
2
The profiler collects data for all operations.
Warning
Profiling can degrade performance and expose unencrypted query data in 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.
--slowms <integer>
Default: 100
The slow operation time threshold, in milliseconds. Operations that run for longer than this threshold are considered slow.
Slow operations are logged based on workingMillis
, which is the amount of time that MongoDB spends working on that operation. This means that factors such as waiting for locks and flow control do not affect whether an operation exceeds the slow operation threshold.
When logLevel is set to 0
, MongoDB records _slow_operations to the diagnostic log at a rate determined byslowOpSampleRate.
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.
For mongod
instances, --slowms affects the diagnostic log and, if enabled, the profiler.
See also:
--slowOpSampleRate <double>
Default: 1.0
The fraction of slow operations that should be profiled or logged.--slowOpSampleRate accepts values between 0 and 1, inclusive.
--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 --slowOpSampleRate.
For mongod
instances, --slowOpSampleRate affects the diagnostic log and, if enabled, the profiler.
--auditCompressionMode
New in version 5.3.
Specifies the compression mode for audit log encryption. You must also enable audit log encryption using either --auditEncryptionKeyUID or--auditLocalKeyFile.
--auditCompressionMode can be set to one of these values:
Value | Description |
---|---|
zstd | Use the zstd algorithm to compress the audit log. |
none (default) | Do not compress the audit log. |
Note
Available only in MongoDB Enterprise. MongoDB Enterprise and Atlas have different configuration requirements.
--auditDestination
Enables auditing and specifies wheremongod
sends all audit events.
--auditDestination 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 infoand a facility level of user.The syslog message limit can result in the truncation of audit messages. The auditing system neither detects the truncation nor errors upon its occurrence. |
console | Output the audit events to stdout in JSON format. |
file | Output the audit events to the file specified in--auditPath in the format specified in--auditFormat. |
Note
--auditEncryptionKeyUID
New in version 6.0.
Specifies the unique identifier of the Key Management Interoperability Protocol (KMIP) key for audit log encryption.
You cannot use --auditEncryptionKeyUID and--auditLocalKeyFile together.
Note
Available only in MongoDB Enterprise. MongoDB Enterprise and Atlas have different configuration requirements.
--auditFormat
Specifies the format of the output file for auditing if --auditDestination is file
. The--auditFormat option can have one of the following values:
Value | Description |
---|---|
JSON | Output the audit events in JSON format to the file specified in --auditPath. |
BSON | Output the audit events in BSON binary format to the file specified in --auditPath. |
Printing audit events to a file in JSON format degrades server performance more than printing to a file in BSON format.
Note
--auditLocalKeyFile
New in version 5.3.
Specifies the path and file name for a local audit key file foraudit log encryption.
Note
Only use --auditLocalKeyFile for testing because the key is not secured. To secure the key, use--auditEncryptionKeyUID and an external Key Management Interoperability Protocol (KMIP) server.
You cannot use --auditLocalKeyFile and--auditEncryptionKeyUID together.
Note
Available only in MongoDB Enterprise. MongoDB Enterprise and Atlas have different configuration requirements.
--auditPath
Specifies the output file for auditing if--auditDestination has value of file
. The--auditPath option can take either a full path name or a relative path name.
Note
--auditFilter
Specifies 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:
{ <field1>: <expression1>, ... }
The <field>
can be any field in the audit message, including fields returned in theparam 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 aconfiguration file, you must use the YAML format of the configuration file.
Note
--auditSchema
Default: mongo
New in version 8.0.
Specifies the format used for audit logs. You can specify one of the following values for --auditSchema
:
Value | Description |
---|---|
mongo | Logs are written in a format designed by MongoDB.For example log messages, see mongo Schema Audit Messages. |
OCSF | Logs are written in OCSF format. This option provides logs in a standardized format compatible with log processors.For example log messages, see OCSF Schema Audit Messages. |
--inMemorySizeGB <float>
Default: 50% of physical RAM minus 1 GB.
Maximum amount of memory to allocate for the in-memory storage engine data, including indexes, the oplog (if themongod
is part of a replica set), sharded cluster metadata, etc.
Values can range from 256MB to 10TB and can be a float.
By default, the in-memory storage engine uses 50% of physical RAM minus 1 GB.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--enableEncryption
Default: false
Enables encryption for the WiredTiger storage engine. This option must be enabled in order to pass in encryption keys and configurations.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--encryptionCipherMode <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 ModeAvailable 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.
--encryptionKeyFile <string>
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 throws an error.
The keyfile can contain only a single key. The key is either a 16 or 32 character string.
Requires --enableEncryption.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipKeyIdentifier <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--enableEncryption.
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.
--kmipRotateMasterKey <boolean>
Default: false
If true, rotate the master key and re-encrypt the internal keystore.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
See also:
--kmipServerName <string>
Hostname or IP address of the KMIP server to connect to. Requires--enableEncryption.
You can specify multiple KMIP servers as a comma-separated list, for example:server1.example.com,server2.example.com
. On startup, themongod
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.
When connecting to a KMIP server, the mongod
verifies that the specified --kmipServerName 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
fails 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.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipPort <number>
Default: 5696
Port number to use to communicate with the KMIP server. Requires --kmipServerName. Requires--enableEncryption.
If specifying multiple KMIP servers with --kmipServerName, the mongod
uses the port specified with--kmipPort for all provided KMIP servers.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipConnectRetries <number>
Default: 0
How many times to retry the initial connection to the KMIP server. Use together with --kmipConnectTimeoutMS to control how long the mongod
waits for a response between each retry.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipConnectTimeoutMS <number>
Default: 5000
Timeout in milliseconds to wait for a response from the KMIP server. If the --kmipConnectRetries setting is specified, the mongod
waits for the specified interval between retries.
Value must be 1000
or greater.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipClientCertificateSelector <string>
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.
--kmipClientCertificateSelector 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 afingerprint. |
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipClientCertificateFile <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 option, you must also specify the--kmipServerName option.
Important
Enabling encryption using a KMIP server on Windows fails when using--kmipClientCertificateFile
and the KMIP server enforces TLS 1.2.
To enable encryption at rest with KMIP on Windows, you must:
- Import the client certificate into the Windows Certificate Store.
- Use the --kmipClientCertificateSelector option.
Note
On macOS or Windows, you can use a certificate from the operating system's secure store instead of a PEM key file. See --kmipClientCertificateSelector.
Note
Enterprise Feature
Available in MongoDB Enterprise only.
--kmipClientCertificatePassword <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.
--kmipServerCAFile <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 --kmipClientCertificateSelector. When using the secure store, you do not need to, but can, also specify the --kmipServerCAFile.
--kmipActivateKeys <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 --kmipActivateKeys
is true
and you have existing keys on a KMIP server, the key must be activated first or the mongodnode 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 --kmipRotateMasterKey.
--kmipKeyStatePollingSeconds <integer>
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
.
--kmipUseLegacyProtocol <boolean>
Default: false
New in version 7.0: (and 6.0.6)
When true
, mongod
uses KMIP protocol version 1.0 or 1.1 instead of the default version. The default KMIP protocol is version 1.2.
To use audit log encryptionwith KMIP version 1.0 or 1.1, you must specifyauditEncryptKeyWithKMIPGet at startup.
--eseDatabaseKeyRollover
Roll over the encrypted storage engine database keys configured withAES256-GCM
cipher.
When mongod
instance is started with this option, the instance rotates the keys and exits.
Note
Enterprise Feature
Available in MongoDB Enterprise only.