Mongodb
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.
For more information about monitoring MongoDB, see /administration/monitoring.
For additional background on various other MongoDB status outputs see:
/reference/server-status
/reference/replica-status
/reference/database-statistics
/reference/collection-statistics
For an additional utility that provides MongoDB metrics see "mongostat."
mongotop
--help
Returns a basic help and usage text.
--verbose, -v
Increases the amount of internal reporting returned on the command line. Increase the verbosity with the -v form by including the option multiple times, (e.g. -vvvvv.)
--version
Print the version of the mongotop utility and exit.
--host <hostname><:port>
Specifies a resolvable hostname for the mongod from which you want to export data. By default mongotop attempts to connect to a MongoDB process running on the localhost port number 27017.
Optionally, specify a port number to connect a MongoDB instance running on a port other than 27017.
To connect to a replica set, you can specify the replica set seed name, and a seed list of set members, in the following format:
<replica_set_name>/<hostname1><:port>,<hostname2:<port>,...
--port <port>
Specifies the port number, if the MongoDB instance is not running on the standard port. (i.e. 27017) You may also specify a port number using the mongotop --host command.
--ipv6
Enables IPv6 support that allows mongotop to connect to the MongoDB instance using an IPv6 network. All MongoDB programs and processes, including mongotop, disable IPv6 support by default.
--username <username>, -u <username>
Specifies a username to authenticate to the MongoDB instance, if your database requires authentication. Use in conjunction with the mongotop option to supply a password.
--password <password>, -p <password>
Specifies a password to authenticate to the MongoDB instance. Use in conjunction with the --username option to supply a username.
If you specify a --username without the --password option, mongotop will prompt for a password interactively.
--authenticationDatabase <dbname>
New in version 2.4.
Specifies the database that holds the user's (e.g --username) credentials.
By default, mongotop assumes that the database specified to the --db argument holds the user's credentials, unless you specify --authenticationDatabase.
See userSource, /reference/privilege-documents and /reference/user-privileges for more information about delegated authentication in MongoDB.
--authenticationMechanism <name>
New in version 2.4.
Specifies the authentication mechanism. By default, the authentication mechanism is MONGODB-CR, which is the MongoDB challenge/response authentication mechanism. In the MongoDB Subscriber Edition, mongotop also includes support for GSSAPI to handle Kerberos authentication.
See /tutorial/control-access-to-mongodb-with-kerberos-authentication for more information about Kerberos authentication.
--locks
New in version 2.2.
Toggles the mode of mongotop to report on use of per-database locks. These data are useful for measuring concurrent operations and lock percentage.
<sleeptime>
The final argument is the length of time, in seconds, that mongotop waits in between calls. By default mongotop returns data every second.
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 --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.
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:
connected to: 127.0.0.1
ns total read write 2012-08-13T15:45:40
test.system.namespaces 0ms 0ms 0ms
local.system.replset 0ms 0ms 0ms
local.system.indexes 0ms 0ms 0ms
admin.system.indexes 0ms 0ms 0ms
admin. 0ms 0ms 0ms
ns total read write 2012-08-13T15:45:55
test.system.namespaces 0ms 0ms 0ms
local.system.replset 0ms 0ms 0ms
local.system.indexes 0ms 0ms 0ms
admin.system.indexes 0ms 0ms 0ms
admin. 0ms 0ms 0ms
To return a mongotop report every 5 minutes, use the following command:
mongotop 300
To report the use of per-database locks, use mongotop --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
MongoDB Documentation Project
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