mongostat (1) Linux Manual Page

NAME

mongostat – MongoDB Use Statistics

SYNOPSIS

The mongostat utility provides a quick overview of the status of a currently running mongod or mongos instance. mongostat is functionally similar to the UNIX/Linux file system utility vmstat, but provides data regarding mongod and mongos instances.

SEE ALSO: For more information about monitoring MongoDB, see http://docs.mongodb.org/manual/administration/monitoring.

For more background on various other MongoDB status outputs see:

•

http://docs.mongodb.org/manual/reference/command/serverStatus

•

http://docs.mongodb.org/manual/reference/command/replSetGetStatus

•

http://docs.mongodb.org/manual/reference/command/dbStats

•

http://docs.mongodb.org/manual/reference/command/collStats

For an additional utility that provides MongoDB metrics see mongotop.

mongostat connects to the mongod instance running on the local host interface on TCP port 27017; however, mongostat can connect to any accessible remote mongod instance.

OPTIONS

mongostat

mongostat

–help, -h

Returns information on mongostat options and usage.

–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.)

–version

Returns the mongostat release number.

–host <hostname><:port>, -h

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

To connect to a replica set, specify the replica set seed name and the seed list of set members. Use the following format:

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

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

–port <port>

Specifies the port number when the MongoDB instance is not running on the standard port of 27017. You may also specify the port number using the –host option.

–ipv6

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

–ssl

New in version 2.6.

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

The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see http://docs.mongodb.org/manual/tutorial/configure-ssl.

–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.

The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see http://docs.mongodb.org/manual/tutorial/configure-ssl.

–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 sslCAFile enabled without sslWeakCertificateValidation.

The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see http://docs.mongodb.org/manual/tutorial/configure-ssl.

–sslPEMKeyPassword <value>

New in version 2.6.

Specifies the password to de-crypt the certificate-key file (i.e. –sslPEMKeyFile). Use –sslPEMKeyPassword only if the certificate-key file is encrypted. In all cases, mongostat 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 –sslPEMKeyPassword, mongostat will prompt for a passphrase. See ssl-certificate-password.

The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see http://docs.mongodb.org/manual/tutorial/configure-ssl.

–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.

The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see http://docs.mongodb.org/manual/tutorial/configure-ssl.

–sslAllowInvalidCertificates

New in version 2.6.

Bypasses the validation checks for server certificates and allows the use of invalid certificates. When using the sslAllowInvalidCertificates 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 http://docs.mongodb.org/manual/tutorial/configure-ssl.

–sslFIPSMode

New in version 2.6.

Directs mongostat to use the FIPS mode of the installed OpenSSL library. Your system must have a FIPS compliant OpenSSL library to use –sslFIPSMode.

The default distribution of MongoDB does not contain support for SSL. For more information on MongoDB and SSL, see http://docs.mongodb.org/manual/tutorial/configure-ssl.

–username <username>, -u

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

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

–authenticationDatabase <dbname>

New in version 2.4.

Specifies the database that holds the user’s credentials. If you do not specify an authentication database, mongostat assumes that the database specified as the argument to the –db option holds the user’s credentials.

–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 MongoDB Enterprise, mongostat also includes support for GSSAPI to handle Kerberos authentication. See http://docs.mongodb.org/manual/tutorial/control-access-to-mongodb-with-kerberos-authentication for more information about Kerberos authentication.

–noheaders

Disables the output of column or field names.

–rowcount <number>, -n

Controls the number of rows to output. Use in conjunction with the sleeptime argument to control the duration of a mongostat operation.

Unless –rowcount is specified, mongostat will return an infinite number of rows (e.g. value of 0.)

–http

Configures mongostat to collect data using the HTTP interface rather than a raw database connection.

–discover

Discovers and reports on statistics from all members of a replica set or sharded cluster. When connected to any member of a replica set, –discover all non-hidden members of the replica set. When connected to a mongos, mongostat will return data from all shards in the cluster. If a replica set provides a shard in the sharded cluster, mongostat will report on non-hidden members of that replica set.

The mongostat –host option is not required but potentially useful in this case.

Changed in version 2.6: When running with –discover, mongostat now respects :option:–rowcount`.

–all

Configures mongostat to return all optional fields.

<sleeptime>

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

mongostat returns values that reflect the operations over a 1 second period. For values of <sleeptime> greater than 1, mongostat averages data to reflect average operations per second.

FIELDS

mongostat returns values that reflect the operations over a 1 second period. When mongostat <sleeptime> has a value greater than 1, mongostat averages the statistics to reflect average operations per second.

mongostat outputs the following fields:

inserts

The number of objects inserted into the database per second. If followed by an asterisk (e.g. *), the datum refers to a replicated operation.

query

The number of query operations per second.

update

The number of update operations per second.

delete

The number of delete operations per second.

getmore

The number of get more (i.e. cursor batch) operations per second.

command

The number of commands per second. On slave and secondary systems, mongostat presents two values separated by a pipe character (e.g. |), in the form of local|replicated commands.

flushes

The number of fsync operations per second.

mapped

The total amount of data mapped in megabytes. This is the total data size at the time of the last mongostat call.

size

The amount of virtual memory in megabytes used by the process at the time of the last mongostat call.

non-mapped

The total amount of virtual memory excluding all mapped memory at the time of the last mongostat call.

res

The amount of resident memory in megabytes used by the process at the time of the last mongostat call.

faults

Changed in version 2.1.

The number of page faults per second.

Before version 2.1 this value was only provided for MongoDB instances running on Linux hosts.

locked

The percent of time in a global write lock.

Changed in version 2.2: The locked db field replaces the locked % field to more appropriate data regarding the database specific locks in version 2.2.

locked db

New in version 2.2.

The percent of time in the per-database context-specific lock. mongostat will report the database that has spent the most time since the last mongostat call with a write lock.

This value represents the amount of time that the listed database spent in a locked state combined with the time that the mongod spent in the global lock. Because of this, and the sampling method, you may see some values greater than 100%.

idx miss

The percent of index access attempts that required a page fault to load a btree node. This is a sampled value.

qr

The length of the queue of clients waiting to read data from the MongoDB instance.

qw

The length of the queue of clients waiting to write data from the MongoDB instance.

ar

The number of active clients performing read operations.

aw

The number of active clients performing write operations.

netIn

The amount of network traffic, in bytes, received by the MongoDB instance.

This includes traffic from mongostat itself.

netOut

The amount of network traffic, in bytes, sent by the MongoDB instance.

This includes traffic from mongostat itself.

conn

The total number of open connections.

set

The name, if applicable, of the replica set.

repl

The replication status of the member.

Value	Replication Type
M	master
SEC	secondary
REC	recovering
UNK	unknown
SLV	slave

USAGE

In the first example, mongostat will return data every second for 20 seconds. mongostat collects data from the mongod instance running on the localhost interface on port 27017. All of the following invocations produce identical behavior:

mongostat --rowcount 20 1
mongostat --rowcount 20
mongostat -n 20 1
mongostat -n 20

In the next example, mongostat returns data every 5 minutes (or 300 seconds) for as long as the program runs. mongostat collects data from the mongod instance running on the localhost interface on port 27017. Both of the following invocations produce identical behavior.

mongostat --rowcount 0 300
mongostat -n 0 300
mongostat 300

In the following example, mongostat returns data every 5 minutes for an hour (12 times.) mongostat collects data from the mongod instance running on the localhost interface on port 27017. Both of the following invocations produce identical behavior.

mongostat --rowcount 12 300
mongostat -n 12 300

In many cases, using the –discover will help provide a more complete snapshot of the state of an entire group of machines. If a mongos process connected to a sharded cluster is running on port 27017 of the local machine, you can use the following form to return statistics from all members of the cluster:

mongostat --discover

AUTHOR

MongoDB Documentation Project

COPYRIGHT

2011-2014, MongoDB, Inc.

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