OPTIONS

mongotop

Synopsis

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

See also

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.

Required Access

In order to connect to a mongod that enforces authorization with the --auth option, you must use the --username and --password options, and the connecting user must have the serverStatus and top privileges.

The most appropriate built-in role that has these privileges is clusterMonitor.

Options

mongotop
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 the 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.

--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:

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

You can always connect directly to a single MongoDB instance by specifying the host and port number directly.

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>]).

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.

--ipv6

Enables IPv6 support and allows the mongotop to connect to the MongoDB instance using an IPv6 network. All MongoDB programs and processes disable IPv6 support by default.

--ssl

New in version 2.6.

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

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

--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.

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

Warning

If the mongo shell or any other tool that connects to mongos or mongod is run without --sslCAFile, it will not attempt to validate server certificates. This results in 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 against which server certificates should be validated in cases where intrusion is a possibility.

--sslPEMKeyFile <filename>

New in version 2.6.

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.

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

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

--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 SSL Certificate Passphrase.

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

--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.

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

--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.

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

--sslAllowInvalidHostnames

New in version 3.0.

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

Changed in version 3.0: Most MongoDB distributions now include support for SSL. See Configure mongod and mongos for SSL for more information about SSL and MongoDB.

--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 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.

--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.

If you do not specify an argument for --password, mongotop will prompt interactively for a password on the console.

--authenticationDatabase <dbname>

New in version 2.4.

Specifies the database that holds the user’s credentials.

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

--authenticationMechanism <name>

Default: SCRAM-SHA-1

New in version 2.4.

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 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.
--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. These data are useful for measuring concurrent operations and lock percentage.

--locks returns an error when called against a mongod instance that does not report 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

mongotop returns time values specified in milliseconds (ms.)

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.

Changed in version 2.2: If you use the mongotop --locks, the ns field does not appear in the mongotop output.

mongotop.db

New in version 2.2.

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.

Use

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.

mongotop 15

This command produces the following output:

                     ns    total    read    write          2014-12-19T15:32:01-05:00
     admin.system.roles      0ms     0ms      0ms
   admin.system.version      0ms     0ms      0ms
               local.me      0ms     0ms      0ms
         local.oplog.rs      0ms     0ms      0ms
 local.replset.minvalid      0ms     0ms      0ms
      local.startup_log      0ms     0ms      0ms
   local.system.indexes      0ms     0ms      0ms
local.system.namespaces      0ms     0ms      0ms
   local.system.replset      0ms     0ms      0ms

                     ns    total    read    write          2014-12-19T15:47:01-05:00
     admin.system.roles      0ms     0ms      0ms
   admin.system.version      0ms     0ms      0ms
               local.me      0ms     0ms      0ms
         local.oplog.rs      0ms     0ms      0ms
 local.replset.minvalid      0ms     0ms      0ms
      local.startup_log      0ms     0ms      0ms
   local.system.indexes      0ms     0ms      0ms
local.system.namespaces      0ms     0ms      0ms
   local.system.replset      0ms     0ms      0ms

The output varies depending on your MongoDB setup. For example, local.system.indexes and local.system.namespaces only appear for mongod instances using the MMAPv1 storage engine.

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

mongotop 300

To report the use of per-database locks, use --locks, which produces the following output:

$ mongotop --locks
connected to: 127.0.0.1

                  db       total        read       write          2012-08-13T16:33:34
               local         0ms         0ms         0ms
               admin         0ms         0ms         0ms
                   .         0ms         0ms         0ms

Changed in version 3.0.0: When called against a mongod that does not report lock usage, --locks will return a Failed: Server does not support reporting locking information error.

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