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- Configuration File Options
Configuration File Options¶
Overview¶
You can control mongod and mongos instances at runtime using a configuration file. The configuration file contains settings that are functionally equivalent to the mongod and mongos command-line arguments but are easier to manage, especially on large-scale deployments. Configuration files allow commenting to describe the reasoning behind a server’s settings.
If you installed from a package and have started MongoDB using your system’s control script, you are already using a configuration file.
Configuration File¶
Important
Changed in version 2.6: MongoDB introduces a YAML-based configuration file format. The 2.4 configuration file format remains for backward compatibility.
File Format¶
The configuration file is in YAML format. For example, the following contains various mongod configuration settings in YAML format:
Note
YAML does not accept tabs; use spaces instead.
systemLog:
destination: file
path: "/var/log/mongodb/mongodb.log"
logAppend: true
storage:
journal:
enabled: true
processManagement:
fork: true
net:
bindIp: 127.0.0.1
port: 27017
setParameter:
enableLocalhostAuthBypass: false
...
Specifying the Configuration File¶
To start mongod or mongos using a config file, specify the config file with the --config option or the -f option.
For example, the following specifies a config file for a mongod:
mongod --config /etc/mongodb.conf
The following specifies a config file for a mongos using the -f alias:
mongos -f /etc/mongodb.conf
Settings¶
Core Options¶
- systemLog¶
- systemLog.verbosity¶
Type: integer
Default: 0
Changed in version 3.0.
Specify the default log message verbosity level for components. The verbosity level determines the amount of Informational and Debug messages MongoDB outputs.
The verbosity level can range from 0 to 5:
- 0 is the MongoDB’s default log verbosity level, to include Informational messages.
- 1 to 5 increases the verbosity level to include Debug messages.
To use a different verbosity level for a named component, use the component’s verbosity setting. For example, use the systemLog.component.accessControl.verbosity to set the verbosity level specifically for ACCESS components.
See the systemLog.component.<name>.verbosity settings for specific component verbosity settings.
For various ways to set the log verbosity level, see Configure Log Verbosity Levels.
- systemLog.component.accessControl.verbosity¶
Type: integer
Default: 0
New in version 3.0.
Specify 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
New in version 3.0.
Specify 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
New in version 3.0.
Specify 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.geo.verbosity¶
Type: integer
Default: 0
New in version 3.0.
Specify 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
New in version 3.0.
Specify 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
New in version 3.0.
Specify 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
New in version 3.0.
Specify 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
New in version 3.0.
Specify 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.sharding.verbosity¶
Type: integer
Default: 0
New in version 3.0.
Specify 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
New in version 3.0.
Specify the log message verbosity level for components related to storage. See STORAGE components.
The systemLog.component.storage.verbosity level applies to journaling components as well if systemLog.component.storage.journal.verbosity is unset.
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
New in version 3.0.
Specify 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 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.write.verbosity¶
Type: integer
Default: 0
New in version 3.0.
Specify 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.
- systemLog.quiet¶
Type: boolean
Runs the mongos or mongod in a quiet mode that attempts to limit the amount of output.
This option is not recommended for production systems as it may make tracking problems during particular connections much more difficult.
- systemLog.traceAllExceptions¶
Type: boolean
Prints verbose information for debugging. Used for additional logging in support-related troubleshooting.
- systemLog.syslogFacility¶
Type: 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.
- systemLog.path¶
Type: string
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 overwrites the log file when the process restarts. To instead append to the log file, set the --logappend option.
- systemLog.logAppend¶
Type: boolean
Default: False
Appends new entries to the end of the log file rather than overwriting the content of the log when the mongos or mongod instance restarts.
- systemLog.logRotate¶
Type: string
Default: rename
New in version 3.0.0: Specifies the logRotate behavior.
Specify either rename or reopen.
rename renames the log file.
reopen closes and reopens the log file following the typical Linux/Unix log rotate behavior. Use reopen when using the Linux/Unix logrotate utility to avoid log loss.
If you specify reopen, systemLog.logAppend must be true.
See also
- systemLog.destination¶
Type: string
Specify either file or syslog. If you specify file you must also specify systemLog.path. If you do not specify systemLog.destination, MongoDB will send all log output to standard output.
- systemLog.timeStampFormat¶
Type: string
Default: iso8601-local
The time format for timestamps in log messages. Specify one of the following values:
Value Description ctime Displays timestamps as Wed Dec 31 18:17:54.811. 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+0500
- processManagement¶
- processManagement.pidFilePath¶
Type: string
Specifies a file location to hold the process ID of the mongos or mongod process where mongos or mongod will write its PID. This is useful for tracking the mongos or mongod process in combination with the --fork option. Without a specified processManagement.pidFilePath option, the process creates no PID file.
- processManagement.fork¶
Type: boolean
Default: False
Enables a daemon mode that runs the mongos or mongod process in the background. By default mongos or mongod does not run as a daemon: typically you will run mongos or mongod as a daemon, either by using processManagement.fork or by using a controlling process that handles the daemonization process (e.g. as with upstart and systemd).
- net¶
- net.port¶
Type: integer
Default: 27017
Specifies the TCP port on which the MongoDB instance listens for client connections.
- net.bindIp¶
Type: string
Default: All interfaces.
Changed in version 2.6.0: The deb and rpm packages include a default configuration file that sets net.bindIp to 127.0.0.1.
Specifies the IP address that mongos or mongod binds to in order to listen for connections from applications. You may attach mongos or mongod to any interface. When attaching mongos or mongod to a publicly accessible interface, ensure that you have implemented proper authentication and firewall restrictions to protect the integrity of your database.
To bind to multiple IP addresses, enter a list of comma separated values.
- net.maxIncomingConnections¶
Type: integer
Default: 65536
The maximum number of simultaneous connections that mongos or mongod will accept. This setting has no effect if it is higher than your operating system’s configured maximum connection tracking threshold.
Changed in version 2.6: MongoDB removed the upward limit on the maxIncomingConnections setting.
This is particularly useful for a mongos if you have a client that creates a number of connections but allows them to timeout rather than close the connections. When you set this option, ensure the value is slightly higher than the size of the connection pool or the total number of connections, to prevent erroneous connection spikes from propagating to the members of a sharded cluster.
- net.wireObjectCheck¶
Type: boolean
Default: True
Forces the mongod or mongos instance to validate all requests from clients upon receipt to prevent clients from inserting malformed or invalid BSON into a MongoDB database.
For objects with a high degree of sub-document nesting, net.wireObjectCheck can have a small impact on performance.
- net.unixDomainSocket¶
- net.unixDomainSocket.enabled¶
Type: boolean
Default: False
Disables listening on the UNIX domain socket. The mongos or mongod process always listens on the UNIX socket unless one of the following is true:
- net.unixDomainSocket.enabled is set
- bindIp is not set
- bindIp does not specify 127.0.0.1
- net.unixDomainSocket.pathPrefix¶
Type: string
Default: /tmp
The path for the UNIX socket. 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:
- --nounixsocket is set
- bindIp is not set
- bindIp does not specify 127.0.0.1
- net.ipv6¶
Type: boolean
Default: False
Enables IPv6 support and allows the mongos or mongod to connect to the MongoDB instance using an IPv6 network. All MongoDB programs and processes disable IPv6 support by default.
- net.http¶
Warning
Ensure that the HTTP status interface, the REST API, and the JSON API are all disabled in production environments to prevent potential data exposure and vulnerability to attackers.
- net.http.enabled¶
Type: boolean
Default: False
New in version 2.6.
Enables the HTTP interface. Enabling the interface can increase network exposure.
Leave the HTTP interface disabled for production deployments. If you do enable this interface, you should only allow trusted clients to access this port. See Firewalls.
Note
While MongoDB Enterprise does support Kerberos authentication, Kerberos is not supported in HTTP status interface in any version of MongoDB.
Changed in version 3.0.
Neither the HTTP status interface nor the REST API support the SCRAM-SHA-1 challenge-response user authentication mechanism introduced in version 3.0.
- net.http.JSONPEnabled¶
Type: boolean
Default: False
Permits JSONP access via an HTTP interface. Enabling the interface can increase network exposure. The net.http.JSONPEnabled option enables the HTTP interface, even if the HTTP interface option is disabled.
The net.http.JSONPEnabled option is available only for mongod.
- net.http.RESTInterfaceEnabled¶
Type: boolean
Default: False
Enables the simple REST API. Enabling the REST API enables the HTTP interface, even if the HTTP interface option is disabled, and as a result can increase network exposure.
The net.http.RESTInterfaceEnabled option is available only for mongod.
- net.ssl¶
- net.ssl.sslOnNormalPorts¶
Type: boolean
Deprecated since version 2.6.
Enables SSL for mongos or mongod.
With net.ssl.sslOnNormalPorts, a mongos or mongod requires SSL encryption for all connections on the default MongoDB port, or the port specified by --port. By default, --sslOnNormalPorts is disabled.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.mode¶
Type: string
New in version 2.6.
Enables SSL or mixed SSL used for all network connections. The argument to the net.ssl.mode option can be one of the following:
Value Description disabled The server does not use SSL. allowSSL Connections between servers do not use SSL. For incoming connections, the server accepts both SSL and non-SSL. preferSSL Connections between servers use SSL. For incoming connections, the server accepts both SSL and non-SSL. requireSSL The server uses and accepts only SSL encrypted connections. The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.PEMKeyFile¶
Type: string
New in version 2.2.
Specifies the .pem file that contains both the SSL certificate and key. Specify the file name of the .pem file using relative or absolute paths.
When SSL is enabled, you must specify net.ssl.PEMKeyFile.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.PEMKeyPassword¶
Type: string
New in version 2.2.
Specifies the password to de-crypt the certificate-key file (i.e. --sslPEMKeyFile). Use the net.ssl.PEMKeyPassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod will redact the password from all logging and reporting output.
Changed in version 2.6: If the private key in the PEM file is encrypted and you do not specify the net.ssl.PEMKeyPassword option, the mongos or mongod will prompt for a passphrase. See SSL Certificate Passphrase.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.clusterFile¶
Type: string
New in version 2.6.
Specifies the .pem file that contains the x.509 certificate-key file for membership authentication for the cluster or replica set.
If net.ssl.clusterFile does not specify the .pem file for internal cluster authentication, the cluster uses the .pem file specified in the PEMKeyFile option.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.clusterPassword¶
Type: string
New in version 2.6.
Specifies the password to de-crypt the x.509 certificate-key file specified with --sslClusterFile. Use the net.ssl.clusterPassword option only if the certificate-key file is encrypted. In all cases, the mongos or mongod will redact the password from all logging and reporting output.
If the x.509 key file is encrypted and you do not specify the net.ssl.clusterPassword option, the mongos or mongod will prompt for a passphrase. See SSL Certificate Passphrase.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.CAFile¶
Type: string
New in version 2.4.
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.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
Warning
If the --sslCAFile option and its target file are not specified, x.509 client and member authentication will not function. mongod, and mongos in sharded systems, will not be able to verify the certificates of processes connecting to it against the trusted certificate authority (CA) that issued them, breaking the certificate chain.
As of version 2.6.4, mongod will not start with x.509 authentication enabled if the CA file is not specified.
- net.ssl.CRLFile¶
Type: string
New in version 2.4.
Specifies the .pem file that contains the Certificate Revocation List. Specify the file name of the .pem file using relative or absolute paths.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.allowConnectionsWithoutCertificates¶
Type: boolean
New in version 2.4.
Changed in version 3.0.0: net.ssl.weakCertificateValidation became net.ssl.allowConnectionsWithoutCertificates. For compatibility, MongoDB processes continue to accept net.ssl.weakCertificateValidation, but all users should update their configuration files.
Disables the requirement for SSL certificate validation that --sslCAFile enables. With the net.ssl.allowConnectionsWithoutCertificates option, the mongos or mongod will accept connections when the client does not present a certificate when establishing the connection.
If the client presents a certificate and the mongos or mongod has net.ssl.allowConnectionsWithoutCertificates enabled, the mongos or mongod will validate the certificate using the root certificate chain specified by --sslCAFile and reject clients with invalid certificates.
Use the net.ssl.allowConnectionsWithoutCertificates option if you have a mixed deployment that includes clients that do not or cannot present certificates to the mongos or mongod.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.allowInvalidCertificates¶
Type: boolean
New in version 2.6.
Bypasses the validation checks for SSL certificates on other servers in the cluster and allows the use of invalid certificates. When using the allowInvalidCertificates setting, MongoDB logs as a warning the use of the invalid certificate.
The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
- net.ssl.allowInvalidHostnames¶
New in version 3.0.
Disables the validation of the hostnames in SSL certificates. Allows mongod to connect to MongoDB instances if the hostname their certificates do not match the specified hostname.
- net.ssl.FIPSMode¶
Type: boolean
New in version 2.4.
Directs the mongos or mongod to use the FIPS mode of the installed OpenSSL library. Your system must have a FIPS compliant OpenSSL library to use the net.ssl.FIPSMode option.
Note
FIPS-compatible SSL is available only in MongoDB Enterprise. See Configure MongoDB for FIPS for more information.
- setParameter¶
Specifies MongoDB parameter or parameters described in MongoDB Server Parameters
To set parameters in the YAML configuration file, use the following format for the specification:
setParameter: <parameter1>: <value1> <parameter2>: <value2>
For example, to specify the enableLocalhostAuthBypass in the configuration file:
setParameter: enableLocalhostAuthBypass: false
- security¶
- security.keyFile¶
Type: string
Specifies the path to a key file that stores the shared secret that MongoDB instances use to authenticate to each other in a sharded cluster or replica set. keyFile implies security.authorization. See Authentication Between MongoDB Instances for more information.
- security.clusterAuthMode¶
Type: string
Default: keyFile
New in version 2.6.
The authentication mode used for cluster authentication. If you use internal x.509 authentication, specify so here. This option can have one of the following values:
Value Description keyFile Use a keyfile for authentication. Accept only keyfiles. sendKeyFile For rolling upgrade purposes. Send a keyfile for authentication but can accept both keyfiles and x.509 certificates. sendX509 For rolling upgrade purposes. Send the x.509 certificate for authentication but can accept both keyfiles and x.509 certificates. x509 Recommended. Send the x.509 certificate for authentication and accept only x.509 certificates. The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see Configure mongod and mongos for SSL.
Type: string
Default: disabled
Enables Role-Based Access Control (RBAC) to govern each user’s access to database resources and operations.
Set this option to one of the following:
Value Description enabled A user can access only the database resources and actions for which they have been granted privileges. disabled A user can access any database and perform any action. See Authorization for more information.
The security.authorization option is available only for mongod.
- security.sasl¶
- security.sasl.hostName¶
Type: string
A fully qualified server domain name for the purpose of configuring SASL and Kerberos authentication. The SASL hostname overrides the hostname only for the configuration of SASL and Kerberos.
For mongo shell and other MongoDB tools to connect to the new hostName, see the gssapiHostName option in the mongo shell and other tools.
- security.sasl.serviceName¶
Type: string
Registered name of the service using SASL. This option allows you to override the default Kerberos service name component of the Kerberos principal name, on a per-instance basis. If unspecified, the default value is mongodb.
MongoDB permits setting this option only at startup. The setParameter can not change this setting.
This option is available only in MongoDB Enterprise.
Important
Ensure that your driver supports alternate service names. For mongo shell and other MongoDB tools to connect to the new serviceName, see the gssapiServiceName option.
- security.sasl.saslauthdSocketPath¶
Type: string
The path to the UNIX domain socket file for saslauthd.
- security.javascriptEnabled¶
Type: boolean
Default: True
Enables or disables the JavaScript execution engine. When disabled, $where, mapReduce, group and any other operation that requires a mongod instance to execute JavaScript.
- operationProfiling¶
- operationProfiling.slowOpThresholdMs¶
Type: integer
Default: 100
The threshold in milliseconds at which the database profiler considers a query slow. MongoDB records all slow queries to the log, even when the database profiler is off. When the profiler is on, it writes to the system.profile collection. See the profile command for more information on the database profiler.
The operationProfiling.slowOpThresholdMs option is available only for mongod.
- operationProfiling.mode¶
Type: string
Default: off
Changes the level of database profiling, which inserts information about operation performance into standard output or a log file. Specify one of the following levels:
Level Setting off Off. No profiling. slowOp On. Only includes slow operations. all On. Includes all operations. Database profiling can impact database performance. Enable this option only after careful consideration.
The operationProfiling.mode option is available only for mongod.
- storage¶
- storage.dbPath¶
Type: string
Default: /data/db on Linux and OS X, \data\db on Windows
The directory where the mongod instance stores its data.
If you installed MongoDB using a package management system, check the /etc/mongodb.conf file provided by your packages to see the directory is specified.
The storage.dbPath option is available only for mongod.
- storage.indexBuildRetry¶
Type: boolean
Default: True
Selects whether mongod rebuilds incomplete indexes on the next start up. This applies in cases where mongod restarts after it has shut down or stopped in the middle of an index build. In such cases, mongod always removes any incomplete indexes, and then, by default, attempts to rebuild them. To stop mongod from rebuilding indexes, set this option to false.
The storage.indexBuildRetry option is available only for mongod.
- storage.repairPath¶
Type: string
Default: A _tmp directory within the path specified by the dbPath option.
Specifies a working directory that MongoDB will use during the --repair operation. After --repair completes, the data files in dbPath and the storage.repairPath directory is empty.
The storage.repairPath option is available only for mongod.
- storage.journal.enabled¶
Type: boolean
Default: true on 64-bit systems, false on 32-bit systems
Enables the durability journal to ensure data files remain valid and recoverable. This option applies only when you specify the --dbpath option. The mongod enables journaling by default on 64-bit builds of versions after 2.0.
The storage.journal.enabled option is available only for mongod.
- storage.directoryPerDB¶
Type: boolean
Default: False
Stores each database’s files in its own folder in the data directory. When applied to an existing system, the storage.directoryPerDB option alters the storage pattern of the data directory.
Use this option in conjunction with your file system and device configuration so that MongoDB will store data on a number of distinct disk devices to increase write throughput or disk capacity.
Warning
To enable this option for an existing system, migrate the database-specific data files to the new directory structure before enabling storage.directoryPerDB. Database-specific data files begin with the name of an existing database and end with either “ns” or a number. For example, the following data directory includes files for the local and test databases:
journal mongod.lock local.0 local.1 local.ns test.0 test.1 test.ns
After migration, the data directory would have the following structure:
journal mongod.lock local/local.0 local/local.1 local/local.ns test/test.0 test/test.1 test/test.ns
The storage.directoryPerDB option is available only for mongod.
- storage.syncPeriodSecs¶
Type: number
Default: 60
Controls how much time can pass before MongoDB flushes data to the data files via an fsync operation. Do not set this value on production systems. In almost every situation, you should use the default setting.
Warning
If you set storage.syncPeriodSecs to 0, MongoDB will not sync the memory mapped files to disk.
The mongod process writes data very quickly to the journal and lazily to the data files. syncPeriodSecs has no effect on the journal files or journaling.
The serverStatus command reports the background flush thread’s status via the backgroundFlushing field.
The storage.syncPeriodSecs option is available only for mongod.
- storage.engine¶
Default: mmapv1
New in version 3.0.0.
Specifies the storage engine for the mongod database. Valid options include mmapv1 and wiredTiger.
If you attempt to start a mongod with a storage.dbPath that contains data files produced by a storage engine other than the one specified by storage.engine, mongod will refuse to start.
- storage.mmapv1¶
- storage.mmapv1.preallocDataFiles¶
Type: boolean
Default: True
Deprecated since version 2.6.
Disables the preallocation of data files. Currently the default. Exists for future compatibility and clarity.
The storage.mmapv1.preallocDataFiles option is available only for mongod.
- storage.mmapv1.nsSize¶
Type: integer
Default: 16
Specifies the default size for namespace files, which are files that end in .ns. Each collection and index counts as a namespace.
Use this setting to control size for newly created namespace files. This option has no impact on existing files. The maximum size for a namespace file is 2047 megabytes. The default value of 16 megabytes provides for approximately 24,000 namespaces.
The storage.mmapv1.nsSize option is available only for mongod.
- storage.mmapv1.quota¶
- storage.mmapv1.quota.enforced¶
Type: Boolean
Default: false
Enables a maximum limit for the number data files each database can have. When running with the storage.mmapv1.quota.enforced option, MongoDB has a maximum of 8 data files per database. Adjust the quota with storage.quota.maxFilesPerDB.
The storage.mmapv1.quota.enforced option is available only for mongod.
- storage.mmapv1.quota.maxFilesPerDB¶
Type: integer
Default: 8
Modifies the limit on the number of data files per database. storage.mmapv1.quota.maxFilesPerDB option requires that you set storage.quota.enforced.
The storage.mmapv1.quota.maxFilesPerDB option is available only for mongod.
- storage.mmapv1.smallFiles¶
Type: boolean
Default: False
Sets MongoDB to use a smaller default file size. The storage.mmapv1.smallFiles option reduces the initial size for data files and limits the maximum size to 512 megabytes. storage.mmapv1.smallFiles also reduces the size of each journal file from 1 gigabyte to 128 megabytes. Use storage.mmapv1.smallFiles if you have a large number of databases that each holds a small quantity of data.
The storage.mmapv1.smallFiles option can lead the mongod instance to create a large number of files, which can affect performance for larger databases.
The storage.mmapv1.smallFiles option is available only for mongod.
- storage.mmapv1.journal¶
- storage.mmapv1.journal.debugFlags¶
Type: integer
Provides functionality for testing. Not for general use, and will affect data file integrity in the case of abnormal system shutdown.
The storage.mmapv1.journal.debugFlags option is available only for mongod.
- storage.mmapv1.journal.commitIntervalMs¶
Type: number
Default: 100 or 30
The maximum amount of time the mongod process allows between journal operations. Values can range from 2 to 300 milliseconds. Lower values increase the durability of the journal, at the expense of disk performance.
The default journal commit interval is 100 milliseconds if a single block device (e.g. physical volume, RAID device, or LVM volume) contains both the journal and the data files.
If the journal is on a different block device than the data files the default journal commit interval is 30 milliseconds.
To force mongod to commit to the journal more frequently, you can specify j:true. When a write operation with j:true is pending, mongod will reduce commitIntervalMs to a third of the set value.
The storage.mmapv1.journal.commitIntervalMs option is available only for mongod.
- storage.wiredTiger¶
- storage.wiredTiger.engineConfig¶
- storage.wiredTiger.engineConfig.cacheSizeGB¶
Default: the maximum of half of physical RAM or 1 gigabyte
New in version 3.0.0.
Defines the maximum size of the cache that WiredTiger will use for all data. Ensure that storage.wiredTiger.engineConfig.cacheSizeGB is sufficient to hold the entire working set for the mongod instance.
- storage.wiredTiger.engineConfig.directoryForIndexes¶
Type: boolean
Default: false
New in version 3.0.0.
When you start mongod with storage.wiredTiger.engineConfig.directoryForIndexes, mongod stores indexes and collections in separate directories.
- storage.wiredTiger.engineConfig.statisticsLogDelaySecs¶
Default: 0
New in version 3.0.0.
When 0 WiredTiger will not log statistics. Otherwise WiredTiger will log statistics to a file in the dbPath on the interval defined by storage.wiredTiger.engineConfig.statisticsLogDelaySecs.
- storage.wiredTiger.collectionConfig¶
- storage.wiredTiger.collectionConfig.blockCompressor¶
Default: snappy
New in version 3.0.0.
Specifies the default type of compression to use to compress collection data. You can override this on a per-collection basis when creating collections.
Available compressors are:
The storage.wiredTiger.collectionConfig.blockCompressor setting affects all collections created. If you change the value of storage.wiredTiger.collectionConfig.blockCompressor on an existing MongoDB deployment, all new collections will use the specified compressor. Existing collections will continue to use the compressor specified when they were created, or the default compressor at that time.
- storage.wiredTiger.indexConfig¶
- storage.wiredTiger.indexConfig.prefixCompression¶
Default: true
New in version 3.0.0.
Specify true for storage.wiredTiger.indexConfig.prefixCompression to enable prefix compression for index data.
The storage.wiredTiger.indexConfig.prefixCompression setting affects all indexes created. If you change the value of storage.wiredTiger.indexConfig.prefixCompression on an existing MongoDB deployment, all new indexes will use prefix compression. Existing indexes are not affected.
- replication¶
- replication.oplogSizeMB¶
Type: integer
Specifies a maximum size in megabytes for the replication operation log (i.e., the oplog). The mongod process creates an oplog based on the maximum amount of space available. For 64-bit systems, the oplog is typically 5% of available disk space. Once the mongod has created the oplog for the first time, changing the replication.oplogSizeMB option will not affect the size of the oplog.
See Oplog Size for more information.
The replication.oplogSizeMB option is available only for mongod.
- replication.replSetName¶
Type: string
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 should have a distinct name. Some drivers group replica set connections by replica set name.
The replication.replSetName option is available only for mongod.
- replication.secondaryIndexPrefetch¶
Type: string
Default: all
New in version 2.2.
Storage Engine Specific Feature
replication.secondaryIndexPrefetch is only available with the mmapv1 storage engine.
Determines which indexes secondary members of a replica set load into memory before applying operations from the oplog. By default secondaries load all indexes related to an operation into memory before applying operations from the oplog. This option can have one of the following values:
Value Description none Secondaries do not load indexes into memory. all Secondaries load all indexes related to an operation. _id_only Secondaries load no additional indexes into memory beyond the already existing _id index. The replication.secondaryIndexPrefetch option is available only for mongod.
Type: string
Selects the role the mongod instance has in the sharded cluster. Set this option to one of the following:
Value Description configsvr Start this instance as a config server. The instance starts on port 27019 by default. shardsvr Start this instance as a shard. The instance starts on port 27018 by default. The sharding.clusterRole option is available only for mongod.
Type: boolean
New in version 2.4.
Changed in version 2.6: sharding.archiveMovedChunks is now the default behavior of MongoDB.
When true, the sharding.archiveMovedChunks option forces the mongod instances to save all documents migrated from this shard during chunk migrations to the moveChunk directory of the storage.dbPath. MongoDB does not delete data stored in moveChunk.
- auditLog¶
- auditLog.destination¶
Type: string
New in version 2.6.
Enables auditing. The auditLog.destination option can have one of the following values:
Value Description syslog Output the audit events to syslog in JSON format. Not available on Windows. Audit messages have a syslog severity level of info and a facility level of user.
The syslog message limit can result in the truncation of audit messages. The auditing system will neither detect the truncation nor error upon its occurrence.
console Output the audit events to stdout in JSON format. file Output the audit events to the file specified in --auditPath in the format specified in --auditFormat. Note
Available only in MongoDB Enterprise.
- auditLog.format¶
Type: string
New in version 2.6.
Specifies the format of the output file for auditing if --auditDestination is file. The auditLog.format option can have one of the following values:
Value Description JSON Output the audit events in JSON format to the file specified in --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
Available only in MongoDB Enterprise.
- auditLog.path¶
Type: string
New in version 2.6.
Specifies the output file for auditing if --auditDestination has value of file. The auditLog.path option can take either a full path name or a relative path name.
Note
Available only in MongoDB Enterprise.
- auditLog.filter¶
Type: string representation of a document
New in version 2.6.
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 the param document. The <expression> is a query condition expression.
To specify an audit filter, enclose the filter document in single quotes to pass the document as a string.
To specify the audit filter in a configuration file, you must use the YAML format of the configuration file.
Note
Available only in MongoDB Enterprise.
- snmp¶
- snmp.subagent¶
Type: boolean
Runs SNMP as a subagent. For more information, see Monitor MongoDB With SNMP on Linux.
The snmp.subagent option is available only for mongod.
- snmp.master¶
Type: boolean
Runs SNMP as a master. For more information, see Monitor MongoDB With SNMP on Linux.
The snmp.master option is available only for mongod.
mongos-only Options¶
- replication.localPingThresholdMs¶
Type: integer
Default: 15
Affects the logic that mongos uses when selecting replica set members to pass read operations from clients. Specify a value in milliseconds. The default value of 15 corresponds to the default value in all of the client drivers.
When mongos receives a request that permits reads to secondary members, the mongos will:
Find the member of the set with the lowest ping time.
Construct a list of replica set members that is within a ping time of 15 milliseconds of the nearest suitable member of the set.
If you specify a value for the replication.localPingThresholdMs option, mongos will construct the list of replica members that are within the latency allowed by this value.
Select a member to read from at random from this list.
The ping time used for a member compared by the replication.localPingThresholdMs setting is a moving average of recent ping times, calculated at most every 10 seconds. As a result, some queries may reach members above the threshold until the mongos recalculates the average.
See the Member Selection section of the read preference documentation for more information.
Type: boolean
Prevents mongos from automatically inserting metadata splits in a sharded collection. If set on all mongos instances, this prevents MongoDB from creating new chunks as the data in a collection grows.
Because any mongos in a cluster can create a split, to totally disable splitting in a cluster you must set sharding.autoSplit on all mongos.
Warning
With sharding.autoSplit enabled, the data in your sharded cluster may become imbalanced over time. Enable with caution.
Type: string
Specifies the configuration database for the sharded cluster. You must specify either 1 or 3 configuration servers, in a comma separated list. Always use 3 config servers in production environments.
All mongos instances must specify the exact same value for sharding.configDB
If your configuration databases reside in more that one data center, order the hosts so that first config sever in the list is the closest to the majority of your mongos instances.
Warning
Never remove a config server from this setting, even if the config server is not available or offline.
Type: integer
Default: 64
Determines the size in megabytes of each chunk in the sharded cluster. A size of 64 megabytes is ideal in most deployments: larger chunk size can lead to uneven data distribution; smaller chunk size can lead to inefficient movement of chunks between nodes.
This option affects chunk size only when you initialize the cluster for the first time. If you later modify the option, the new value has no effect. See the Modify Chunk Size in a Sharded Cluster procedure if you need to change the chunk size on an existing sharded cluster.
Windows Service Options¶
- processManagement.windowsService¶
- processManagement.windowsService.serviceName¶
Type: string
Default: MongoDB
Set the service name of mongos or mongod when running as a Windows Service. Use this name with the net start <name> and net stop <name> operations.
You must use processManagement.windowsService.serviceName in conjunction with either the --install or --remove install option.
- processManagement.windowsService.displayName¶
Type: string
Default: MongoDB
Sets the name listed for MongoDB on the Services administrative application.
- processManagement.windowsService.description¶
Type: string
Default: MongoDB Server
Sets the mongos or mongod service description.
You must use processManagement.windowsService.description in conjunction with the --install option.
For descriptions that contain spaces, you must enclose the description in quotes.
- processManagement.windowsService.serviceUser¶
Type: string
Runs the mongos or mongod service in the context of a certain user. This user must have “Log on as a service” privileges.
You must use processManagement.windowsService.serviceUser in conjunction with the --install option.
- processManagement.windowsService.servicePassword¶
Type: string
Sets the password for <user> for mongos or mongod when running with the --serviceUser option.
You must use processManagement.windowsService.servicePassword in conjunction with the --install option.