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mongotop

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macOS Sierra and Go 1.6 Incompatibility

Users running on macOS Sierra require the 3.2.10 or newer version of mongotop.

Description

mongotop provides a method to track the amount of time a MongoDB instance mongod spends reading and writing data. mongotop provides statistics on a per-collection level. By default, mongotop returns values every second.

Run mongotop from the system command line, not the mongo shell.

Syntax

Default

copy 
mongotop [frequency]

You can run mongotop without any command-line options to connect to the mongod instance running on the localhost port 27017. By default, mongotop returns values every second.

copy 
mongotop

To have mongotop report every 30 seconds, specify the time:

copy 
mongotop 30

When connected to a mongod instance, the program reports first on the connection and then reports on the statistics at the configured frequency.

copy 
2019-04-29T15:35:27.785-0400 connected to: 127.0.0.1

             ns    total      read      write    <timestamp>
<db.collection>    81802ms     0ms    81802ms
...

Command Line Options

copy 
mongotop [options] [frequency]

You can run mongotop with various command-line options.

For example, to connect mongotop to a mongod instance running on a remote host mongodb0.example.com and report every 30 seconds:

  • You can include the desired frequency of reporting (in this example, 30 seconds) and the --uri option to specify the host and port:

    copy 
    mongotop 30 --uri mongodb://mongodb0.example.com:27017 [additional options]

    If the mongod instance requires authentication, you can specify the user, password, and authentication database as part of the URI connection string:

    copy 
    mongotop 30 --uri mongodb://user:password@mongodb0.example.com:27017/?authSource=admin [additional options]

    The user running mongotop must have the serverStatus and top privileges.

    For more information on the URI connection string, see --uri.

  • Alternatively, you can use the --host and --port options to specify the host and port:

    copy 
    mongotop 30 --host mongodb0.example.com --port 27017 [additional options]

    If the mongod instance requires authentication, you can specify the user -u, password -p, and the authentication database --authenticationDatabase.

    copy 
    mongotop 30 --host mongodb0.example.com --port 27017 -u user -p password --authenticationDatabase admin [additional options]

    The user running mongotop must have the serverStatus and top privileges.

For more information on the options available, see Options.

When connected to a mongod instance, the program reports first on the connection and then reports on the statistics at the configured frequency.

copy 
2019-04-29T15:35:27.785-0400 connected to: 127.0.0.1

             ns    total      read      write    <timestamp>
<db.collection>    81802ms     0ms    81802ms
...

Required Access

In order to connect to a mongod that enforces authorization, the connecting user must have the serverStatus and top privileges.

The built-in role clusterMonitor provides these privileges.

Options

mongotop
--help

Returns information on the options and use of mongotop.

--verbose, -v

Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the -v form by including the option multiple times, (e.g. -vvvvv.)

--quiet

Runs mongotop in a quiet mode that attempts to limit the amount of output.

This option suppresses:

  • output from database commands
  • replication activity
  • connection accepted events
  • connection closed events
--version

Returns the mongotop release number.

--uri <connectionString>

New in version 3.4.6.

Specify a resolvable URI connection string to connect to the MongoDB deployment.

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--uri "mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database][?options]]"

For more information on the components of the connection string, see the Connection String URI Format documentation.

Important

The following command-line options cannot be used in conjunction with --uri option:

Instead, specify these options as part of your --uri connection string.

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

Default: localhost:27017

Specifies a resolvable hostname for the mongod to which to connect. By default, the mongotop attempts to connect to a MongoDB instance running on the localhost on port number 27017.

To connect to a replica set, specify the replSetName and a seed list of set members, as in the following:

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

When specifying the replica set list format, mongotop always connects to the primary.

You can also connect to any single member of the replica set by specifying the host and port of only that member:

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--host <hostname1><:port>

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

Note

You cannot specify both --host and --uri.

If connected to a replica set where the primary is not reachable, mongotop returns an error message.

--port <port>

Default: 27017

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

Note

You cannot specify both --port and --uri.

--ipv6

Removed in version 3.0.

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

--ssl

New in version 2.6.

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

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

--sslCAFile <filename>

New in version 2.6.

Specifies the .pem file that contains the root certificate chain from the Certificate Authority. Specify the file name of the .pem file using relative or absolute paths.

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

If using x.509 authentication, --sslCAFile or ssl.CAFile must be specified.

Warning

Version 3.2 and earlier: For TLS/SSL connections (--ssl) to mongod and mongos, if the mongotop runs without the --sslCAFile, mongotop will not attempt to validate the server certificates. This creates a vulnerability to expired mongod and mongos certificates as well as to foreign processes posing as valid mongod or mongos instances. Ensure that you always specify the CA file to validate the server certificates in cases where intrusion is a possibility.

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

--sslPEMKeyFile <filename>

New in version 2.6.

Specifies the .pem file that contains both the TLS/SSL certificate and key. Specify the file name of the .pem file using relative or absolute paths.

This option is required when using the --ssl option to connect to a mongod or mongos that has CAFile enabled without allowConnectionsWithoutCertificates.

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

--sslPEMKeyPassword <value>

New in version 2.6.

Specifies the password to de-crypt the certificate-key file (i.e. --sslPEMKeyFile). Use the --sslPEMKeyPassword option only if the certificate-key file is encrypted. In all cases, the mongotop will redact the password from all logging and reporting output.

If the private key in the PEM file is encrypted and you do not specify the --sslPEMKeyPassword option, the mongotop will prompt for a passphrase. See TLS/SSL Certificate Passphrase.

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

--sslCRLFile <filename>

New in version 2.6.

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

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

--sslAllowInvalidCertificates

New in version 2.6.

Bypasses the validation checks for server certificates and allows the use of invalid certificates. When using the allowInvalidCertificates setting, MongoDB logs as a warning the use of the invalid certificate.

Starting in MongoDB 3.4.16, if you specify --sslAllowInvalidCertificates or ssl.allowInvalidCertificates: true when using x.509 authentication, an invalid certificate is only sufficient to establish a TLS/SSL connection but is insufficient for authentication.

Warning

For TLS/SSL connections to mongod and mongos, avoid using --sslAllowInvalidCertificates if possible and only use --sslAllowInvalidCertificates on systems where intrusion is not possible.

If the mongo shell (and other MongoDB Tools) runs with the --sslAllowInvalidCertificates option, the mongo shell (and other MongoDB Tools) will not attempt to validate the server certificates. This creates a vulnerability to expired mongod and mongos certificates as well as to foreign processes posing as valid mongod or mongos instances.

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

--sslAllowInvalidHostnames

New in version 3.0.

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

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

--sslFIPSMode

New in version 2.6.

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

Note

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

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

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

Note

You cannot specify both --username and --uri.

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

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

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

Note

You cannot specify both --password and --uri.

--authenticationDatabase <dbname>

Specifies the authentication database where the specified --username has been created. See Authentication Database.

Note

You cannot specify both --authenticationDatabase and --uri.

Changed in version 3.0.0: --authenticationDatabase is required for mongod and mongos instances that use Authentication.

--authenticationMechanism <name>

Default: SCRAM-SHA-1

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

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

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

Value Description
SCRAM-SHA-1 RFC 5802 standard Salted Challenge Response Authentication Mechanism using the SHA1 hash function.
MONGODB-CR MongoDB challenge/response authentication.
MONGODB-X509 MongoDB TLS/SSL certificate authentication.
GSSAPI (Kerberos) External authentication using Kerberos. This mechanism is available only in MongoDB Enterprise.
PLAIN (LDAP SASL) External authentication using LDAP. You can also use PLAIN for authenticating in-database users. PLAIN transmits passwords in plain text. This mechanism is available only in MongoDB Enterprise.

Note

You cannot specify both --authenticationMechanism and --uri.

--gssapiServiceName

New in version 2.6.

Specify the name of the service using GSSAPI/Kerberos. Only required if the service does not use the default name of mongodb.

This option is available only in MongoDB Enterprise.

--gssapiHostName

New in version 2.6.

Specify the hostname of a service using GSSAPI/Kerberos. Only required if the hostname of a machine does not match the hostname resolved by DNS.

This option is available only in MongoDB Enterprise.

--locks

Toggles the mode of mongotop to report on use of per-database locks. This data is only available when connected to a MongoDB 2.6 or older instance.

--locks returns an error when called against a mongod 3.0 or newer instance that does not report per-database lock usage.

--rowcount int, -n int

Number of lines of data that mongotop should print. “0 for indefinite”

--json

New in version 3.0.0.

Returns output for mongotop in JSON format.

<sleeptime>

The final argument is the length of time, in seconds, that mongotop waits in between calls. By default mongotop returns data every second.

Fields

When connected to a mongod instance, the program reports first on the connection and then reports on the statistics at the configured frequency. mongotop returns time values specified in milliseconds (ms.)

copy 
2019-04-29T15:35:27.785-0400 connected to: 127.0.0.1

             ns    total      read      write    <timestamp>
<db.collection>    81802ms     0ms    81802ms
...

             ns    total      read      write    <timestamp>
<db.collection>    0ms         0ms        0ms
...

mongotop only reports active namespaces or databases, depending on the --locks option. If you don’t see a database or collection, it has received no recent activity. You can issue a simple operation in the mongo shell to generate activity to affect the output of mongotop.

mongotop.ns

Contains the database namespace, which combines the database name and collection.

If you use the mongotop --locks, the ns field does not appear in the mongotop output.

mongotop.db

Contains the name of the database. The database named . refers to the global lock, rather than a specific database.

This field does not appear unless you have invoked mongotop with the --locks option.

mongotop.total

Provides the total amount of time that this mongod spent operating on this namespace.

mongotop.read

Provides the amount of time that this mongod spent performing read operations on this namespace.

mongotop.write

Provides the amount of time that this mongod spent performing write operations on this namespace.

mongotop.<timestamp>

Provides a time stamp for the returned data.

Examples

By default mongotop connects to the MongoDB instance running on the localhost port 27017. However, mongotop can optionally connect to remote mongod instances. See the mongotop options for more information.

To force mongotop to return less frequently specify a number, in seconds at the end of the command. In this example, mongotop will return every 15 seconds.

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mongotop 15

This command produces the following output:

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2019-04-29T15:35:27.785-0400 connected to: 127.0.0.1

                    ns    total    read    write    2019-04-29T15:35:57-04:00
    admin.system.roles      0ms     0ms      0ms
    admin.system.users      0ms     0ms      0ms
  admin.system.version      0ms     0ms      0ms
config.system.sessions      0ms     0ms      0ms
     local.startup_log      0ms     0ms      0ms
  local.system.replset      0ms     0ms      0ms

To return a mongotop report every 5 minutes, use the following command:

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mongotop 300

Additional Information

For more information about monitoring MongoDB, see Monitoring for MongoDB.

For additional background on various other MongoDB status outputs see:

For an additional utility that provides MongoDB metrics see mongostat.

←   mongostat mongoperf  →

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