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Synopsis
The mongostat
utility provides a quick overview of the
status of a currently running mongod
or
mongos
instance. Use mongostat
to help
identify system bottlenecks.
mongostat
is functionally
similar to the UNIX/Linux file system utility vmstat
, but provides
data regarding mongod
and mongos
instances.
Run mongostat
from the system command line, not the mongo
shell.
Versioning
Starting with MongoDB 4.4, mongostat
is now released separately
from the MongoDB Server and uses its own versioning, with an initial
version of 100.0.0
. Previously, mongostat
was released
alongside the MongoDB Server and used matching versioning.
For documentation on the MongoDB 4.2 or earlier versions of
mongostat
, reference the MongoDB Server Documentation for that version of the tool:
Note
Quick links to older documentation
This documentation is for version 100.8.0
of mongostat
.
Compatibility
MongoDB Server Compatibility
mongostat
version 100.8.0
supports the following versions
of the MongoDB Server:
MongoDB 6.0
MongoDB 5.0
MongoDB 4.4
MongoDB 4.2
While mongostat
may work on earlier versions of MongoDB server,
any such compatibility is not guaranteed.
Platform Support
mongostat
version 100.8.0
is supported on the following
platforms:
x86_64 | ARM64 | PPC64LE | s390x | |
---|---|---|---|---|
Amazon Linux 2023 | ✓ | ✓ | ||
Amazon 2 | ✓ | |||
Amazon 2013.03+ | ✓ | |||
Debian 10 | ✓ | |||
Debian 9 | ✓ | |||
Debian 8 | ✓ | |||
RHEL / CentOS 9 | ✓ | ✓ | ||
RHEL / CentOS 8 | ✓ | ✓ | ||
RHEL / CentOS 7 | ✓ | ✓ | ✓ | |
RHEL / CentOS 6 | ✓ | |||
SUSE 15 | ✓ | |||
SUSE 12 | ✓ | |||
Ubuntu 20.04 | ✓ | ✓ | ||
Ubuntu 18.04 | ✓ | ✓ | ||
Ubuntu 16.04 | ✓ | ✓ | ✓ | |
Windows 8 and later | ✓ | |||
Windows Server 2012 and later | ✓ | |||
macOS 11 and later | ✓ | ✓ | ||
macOS 10.12 - 10.15 | ✓ |
Installation
The mongostat
tool is part of the MongoDB Database Tools package:
➤ Follow the Database Tools Installation Guide to install mongostat
.
Syntax
The mongostat
command has the following form:
mongostat <options> <connection-string> <polling interval in seconds>
Run mongostat
from the system command line, not the mongo
shell.
Required Access
In order to connect to a mongod
that enforces authorization
with the --auth
option, specify the
--username
and --password
options, and the connecting user must have the
serverStatus
privilege action on the cluster resources.
The built-in role clusterMonitor
provides this privilege as
well as other privileges. To create a role with just the privilege to
run mongostat
, see Create a Role to Run mongostat.
Behavior
FIPS
mongostat
automatically creates FIPS-compliant
connections to a mongod
/mongos
that is
configured to use FIPS mode.
Options
--help
Returns information on the options and use of
mongostat
.
--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.
--config=<filename>
New in version 100.3.0.
Specifies the full path to a YAML configuration file containing sensitive values for the following options to
mongostat
:This is the recommended way to specify a password to
mongostat
, aside from specifying it through a password prompt.The configuration file takes the following form:
password: <password> uri: mongodb://mongodb0.example.com:27017 sslPEMKeyPassword: <password> Specifying a password to the
password:
field and providing a connection string in theuri:
field which contains a conflicting password will result in an error.Be sure to secure this file with appropriate filesystem permissions.
Note
If you specify a configuration file with
--config
and also use the--password
,--uri
or--sslPEMKeyPassword
option tomongostat
, each command line option overrides its corresponding option in the configuration file.
--uri=<connectionString>
Specifies the resolvable URI connection string of the MongoDB deployment, enclosed in quotes:
--uri="mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database][?options]]" Starting with version
100.0
ofmongostat
, the connection string may alternatively be provided as a positional parameter, without using the--uri
option:mongostat mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database][?options]] As a positional parameter, the connection string may be specified at any point on the command line, as long as it begins with either
mongodb://
ormongodb+srv://
. For example:mongostat --username joe --password secret1 mongodb://mongodb0.example.com:27017 --ssl Only one connection string can be provided. Attempting to include more than one, whether using the
--uri
option or as a positional argument, will result in an error.For information on the components of the connection string, see the Connection String URI Format documentation.
Note
Some components in the
connection string
may alternatively be specified using their own explicit command-line options, such as--username
and--password
. Providing a connection string while also using an explicit option and specifying conflicting information will result in an error.Note
If using
mongostat
on Ubuntu 18.04, you may experience acannot unmarshal DNS
error message when using SRV connection strings (in the formmongodb+srv://
) with the--uri
option. If so, use one of the following options instead:the
--uri
option with a non-SRV connection string (in the formmongodb://
)the
--host
option to specify the host to connect to directly
Warning
On some systems, a password provided in a connection string with the
--uri
option may be visible to system status programs such asps
that may be invoked by other users. Consider instead:omitting the password in the connection string to receive an interactive password prompt, or
using the
--config
option to specify a configuration file containing the password.
--host=<hostname><:port>, -h=<hostname><:port>
Default: localhost:27017
Specifies the resolvable hostname of the MongoDB deployment. By default,
mongostat
attempts to connect to a MongoDB instance running on the localhost on port number27017
.To connect to a replica set, you can specify the set member or members to report on, as in the following (see also the
--discover
flag):--host=<hostname1><:port>,<hostname2><:port>,<...> 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>]
).Alternatively, you can also specify the hostname directly in the
URI connection string
. Providing a connection string while also using--host
and specifying conflicting information will result in an error.
--port=<port>
Default: 27017
Specifies the TCP port on which the MongoDB instance listens for client connections.
Alternatively, you can also specify the port directly in the
URI connection string
. Providing a connection string while also using--port
and specifying conflicting information will result in an error.
--ssl
Enables connection to a
mongod
ormongos
that has TLS/SSL support enabled.Alternatively, you can also configure TLS/SSL support directly in the
URI connection string
. Providing a connection string while also using--ssl
and specifying conflicting information will result in an error.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.
--sslCAFile=<filename>
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.Alternatively, you can also specify the
.pem
file directly in theURI connection string
. Providing a connection string while also using--sslCAFile
and specifying conflicting information will result in an error.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.
--sslPEMKeyFile=<filename>
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 amongod
ormongos
that hasCAFile
enabled withoutallowConnectionsWithoutCertificates
.Alternatively, you can also specify the
.pem
file directly in theURI connection string
. Providing a connection string while also using--sslPEMKeyFile
and specifying conflicting information will result in an error.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.
--sslPEMKeyPassword=<value>
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, themongostat
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, themongostat
will prompt for a passphrase. See TLS/SSL Certificate Passphrase.Alternatively, you can also specify the password directly in the
URI connection string
. Providing a connection string while also using--sslPEMKeyPassword
and specifying conflicting information will result in an error.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.
Warning
On some systems, a password provided directly using the
--sslPEMKeyPassword
option may be visible to system status programs such asps
that may be invoked by other users. Consider using the--config
option to specify a configuration file containing the password instead.
--sslCRLFile=<filename>
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
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.Warning
Although available, avoid using the
--sslAllowInvalidCertificates
option if possible. If the use of--sslAllowInvalidCertificates
is necessary, only use the option on systems where intrusion is not possible.Connecting to a
mongod
ormongos
instance without validating server certificates is a potential security risk. If you only need to disable the validation of the hostname in the TLS/SSL certificates, see--sslAllowInvalidHostnames
.Alternatively, you can also disable certificate validation directly in the
URI connection string
. Providing a connection string while also using--sslAllowInvalidCertificates
and specifying conflicting information will result in an error.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.
--sslAllowInvalidHostnames
Disables the validation of the hostnames in TLS/SSL certificates. Allows
mongostat
to connect to MongoDB instances even if the hostname in their certificates do not match the specified hostname.Alternatively, you can also disable hostname validation directly in the
URI connection string
. Providing a connection string while also using--sslAllowInvalidHostnames
and specifying conflicting information will result in an error.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients.
--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.Alternatively, you can also specify the username directly in the
URI connection string
. Providing a connection string while also using--username
and specifying conflicting information will result in an error.If connecting to a MongoDB Atlas cluster using the
MONGODB-AWS
authentication mechanism
, you can specify your AWS access key ID in:this field,
the
connection string
, orthe
AWS_ACCESS_KEY_ID
environment variable.
See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials for an example of each.
--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.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=""
.Alternatively, you can also specify the password directly in the
URI connection string
. Providing a connection string while also using--password
and specifying conflicting information will result in an error.If connecting to a MongoDB Atlas cluster using the
MONGODB-AWS
authentication mechanism
, you can specify your AWS secret access key in:this field,
the
connection string
, orthe
AWS_SECRET_ACCESS_KEY
environment variable.
See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials for an example of each.
Warning
On some systems, a password provided directly using the
--password
option may be visible to system status programs such asps
that may be invoked by other users. Consider instead:omitting the
--password
option to receive an interactive password prompt, orusing the
--config
option to specify a configuration file containing the password.
--awsSessionToken=<AWS Session Token>
If connecting to a MongoDB Atlas cluster using the
MONGODB-AWS
authentication mechanism
, and using session tokens in addition to your AWS access key ID and secret access key, you can specify your AWS session token in:this field,
the
AWS_SESSION_TOKEN
authMechanismProperties
parameter to theconnection string
, orthe
AWS_SESSION_TOKEN
environment variable.
See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials for an example of each.
Only valid when using the
MONGODB-AWS
authentication mechanism
.
--authenticationDatabase=<dbname>
Specifies the authentication database where the specified
--username
has been created. See Authentication Database.--authenticationDatabase
is required formongod
andmongos
instances that use Authentication.If using the GSSAPI (Kerberos), PLAIN (LDAP SASL), or
MONGODB-AWS
authentication mechanisms
, you must set--authenticationDatabase
to$external
.Alternatively, you can also specify the authentication database directly in the
URI connection string
. Providing a connection string while also using--authenticationDatabase
and specifying conflicting information will result in an error.
--authenticationMechanism=<name>
Default: SCRAM-SHA-1
Specifies the authentication mechanism the
mongostat
instance uses to authenticate to themongod
ormongos
.Changed in version 100.1.0: Starting in version
100.1.0
,mongostat
adds support for theMONGODB-AWS
authentication mechanism when connecting to a MongoDB Atlas cluster.ValueDescriptionRFC 5802 standard Salted Challenge Response Authentication Mechanism using the SHA-1 hash function.RFC 7677 standard Salted Challenge Response Authentication Mechanism using the SHA-256 hash function.
Requires featureCompatibilityVersion set to
4.0
.MongoDB TLS/SSL certificate authentication.MONGODB-AWS
External authentication using AWS IAM credentials for use in connecting to a MongoDB Atlas cluster. See Connect to a MongoDB Atlas Cluster using AWS IAM Credentials.
New in version 100.1.0.
GSSAPI (Kerberos)External authentication using Kerberos. This mechanism is available only in MongoDB Enterprise.PLAIN (LDAP SASL)External authentication using LDAP. You can also usePLAIN
for authenticating in-database users.PLAIN
transmits passwords in plain text. This mechanism is available only in MongoDB Enterprise.Alternatively, you can also specify the authentication mechanism directly in the
URI connection string
. Providing a connection string while also using--authenticationMechanism
and specifying conflicting information will result in an error.
--gssapiServiceName=<string>
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=<string>
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.
--humanReadable=<boolean>
Default: true
When
true
,mongostat
formats dates and quantity values for easier reading, as in the following sample output:insert query update delete getmore command dirty used flushes vsize res qrw arw net_in net_out conn time 991 *0 *0 *0 0 2|0 3.4% 4.5% 0 2.90G 297M 0|0 0|0 12.9m 84.2k 2 Oct 6 09:45:37.478 989 *0 *0 *0 0 2|0 3.6% 4.7% 0 2.91G 310M 0|0 0|0 12.9m 84.1k 2 Oct 6 09:45:38.476 988 *0 *0 *0 0 1|0 3.7% 4.8% 0 2.92G 323M 0|0 0|0 12.8m 83.8k 2 Oct 6 09:45:39.481 976 *0 *0 *0 0 2|0 3.9% 5.0% 0 2.94G 335M 0|0 0|0 12.7m 83.7k 2 Oct 6 09:45:40.476 When
false
,mongostat
returns the raw data, as in the following sample output:insert query update delete getmore command dirty used flushes vsize res qrw arw net_in net_out conn time 992 *0 *0 *0 0 2|0 1.3 2.4 0 2941255680 149946368 0|0 0|0 12913607 84271 2 2016-10-06T09:45:25-04:00 989 *0 *0 *0 0 1|0 1.5 2.6 0 2974810112 163577856 0|0 0|0 12873225 84087 2 2016-10-06T09:45:26-04:00 996 *0 *0 *0 0 1|0 1.6 2.8 0 2972712960 177209344 0|0 0|0 12955423 84345 2 2016-10-06T09:45:27-04:00 987 *0 *0 *0 0 1|0 1.8 2.9 0 2989490176 190840832 0|0 0|0 12861852 84008 2 2016-10-06T09:45:28-04:00
-o=<field list>
When output fields are specified with
-o
, only the specified fields are included in themongostat
output.Use dot notation to specify
serverStatus fields
, as inmetrics.document.inserted
.A custom field name can include spaces. If you include a space, do not put additional quotes around the field name. To specify a custom name for a field, use
<field>=<customName>
, as in:mongostat -o='host=H,time=T,version=MongoDB Version' -o
supports the following methods to modify the information returned for a given serverStatus field:.rate()
Use
.rate()
to view the rate per second at which a serverStatus field is changing frommongostat
call to call.View Rate of Change for a Field with
.rate()
illustrates how to usemongostat
with-o
and the.rate()
method.
.diff()
Use
.diff()
to view how much a serverStatus field has changed since the previousmongostat
call. The interval between calls is specified by<sleeptime>
.View Field Changes with
.diff()
illustrates how to usemongostat
with-o
and the.diff()
method.
mongostat
supports specifying either-o
or-O
: you cannot include both options.See Specify
mongostat
Output Fields for an example of-o
.
-O=<field list>
When specified,
mongostat
includes the specifiedserverStatus
fields after the defaultmongostat
output.Use dot notation to specify
serverStatus fields
, as inmetrics.document.inserted
.A custom field name can include spaces. If you include a space, do not put additional quotes around the field name. To specify a custom name for a field, use
<field>=<customName>
, as in:mongostat -O=host=H,time=T mongostat
supports specifying either-O
or-o
: you cannot include both options.See Add Fields to
mongostat
Output for an example of-O
.
--rowcount=<number>, -n=<number>
Controls the number of rows to output. Use in conjunction with the
sleeptime
argument to control the duration of amongostat
operation.Unless
--rowcount
is specified,mongostat
will return an infinite number of rows (e.g. value of0
.)
--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 amongos
,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.When running with
--discover
,mongostat
respects--rowcount
.
--interactive
Display
mongostat
output in an interactive non-scrolling interface rather than the default scrolling output.--interactive
is not available with the--json
option.See: View Statistics in an Interactive Interface for an example of
--interactive
.
<sleeptime>
Default: 1
The final
mongostat
argument is the length of time, in seconds, thatmongostat
waits in between calls. By defaultmongostat
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 secondary systems,
mongostat
presents two values separated by a pipe character (e.g.|
), in the form oflocal|replicated
commands.
flushes
For the WiredTiger Storage Engine,
flushes
refers to the number of WiredTiger checkpoints triggered between each polling interval.
dirty
Only for WiredTiger Storage Engine. The percentage of the WiredTiger cache with dirty bytes, calculated by
wiredTiger.cache.tracked dirty bytes in the cache
/wiredTiger.cache.maximum bytes configured
.
used
Only for WiredTiger Storage Engine. The percentage of the WiredTiger cache that is in use, calculated by
wiredTiger.cache.bytes currently in the cache
/wiredTiger.cache.maximum bytes configured
.
vsize
The amount of virtual memory in megabytes used by the process 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.
locked
The percent of time in a global write lock. Only appears when
mongostat
runs against pre-3.0 versions of MongoDB instances.
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.
Examples
Run mongostat
from the system command line, not the mongo
shell.
Specify mongostat
Collection Period and Frequency
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
. 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. The following invocations produce identical
behavior:
mongostat --rowcount=12 300 mongostat -n=12 300
Add Fields to mongostat
Output
-O
allows you to specify fields from the
serverStatus
output to add to the default
mongostat
output. If you include a space in your
custom filed name, do not put additional quotes around the field name.
The following example adds fields to the default
mongostat
output:
mongostat -O='host,version,network.numRequests=network requests'
The mongostat
output resembles:
insert query update delete getmore command dirty used flushes vsize res qrw arw net_in net_out conn time host version network requests *0 *0 *0 *0 0 2|0 0.0% 0.0% 0 2.51G 19.0M 0|0 0|0 158b 39.4k 2 Oct 11 12:14:45.878 localhost:37017 3.3.14 91 *0 *0 *0 *0 0 1|0 0.0% 0.0% 0 2.51G 19.0M 0|0 0|0 157b 39.3k 2 Oct 11 12:14:46.879 localhost:37017 3.3.14 95 *0 *0 *0 *0 0 1|0 0.0% 0.0% 0 2.51G 19.0M 0|0 0|0 157b 39.2k 2 Oct 11 12:14:47.884 localhost:37017 3.3.14 99
The following fields are added to the default output:
The network.numRequests
field has a custom field name,
"network requests".
Specify mongostat
Output Fields
-o
specifies the columns
mongostat
includes in its output. You can specify any
serverStatus
field as a mongostat
output
column.
The following example uses custom fields for mongostat
:
mongostat --port 27500 -o='host,opcounters.insert.rate()=Insert Rate,opcounters.query.rate()=Query Rate,opcounters.command.rate()=Command Rate,wiredTiger.cache.pages requested from the cache=Pages Req,metrics.document.inserted=inserted rate'
The mongostat
output resembles:
host Insert Rate Query Rate Command Rate Pages Req Inserted Rate localhost:27500 180 1 8 2999446 9638 localhost:27500 40 3 12 2999601 9678 localhost:27500 181 2 9 3000207 9859 localhost:27500 39 2 12 3000362 9899 localhost:27500 181 2 11 3000969 10080 localhost:27500 39 2 10 3001124 10120
The counters and corresponding custom field names are:
Counter | Custom Field Name |
---|---|
opcounters.insert.rate | Insert Rate |
opcounters.query.rate | Query Rate |
opcounters.command.rate | Command Rate |
wiredTiger.cache.pages requested from the cache | Pages Req |
metrics.document.inserted | Inserted Rate |
View Rate of Change for a Field with .rate()

.rate()
enables you to view the rate per second at which a
numerical field has changed from one mongostat
call to the
next. For example, you can view the rate at which documents have been
inserted during an insert operation. .rate()
can therefore
help you view the performance of your mongod
instance.
The following example reports on the rate of change of the
metrics.document.inserted
serverStatus
field. The
invocation uses -o
's ability to specify the name of an column
to label metrics.document.inserted.rate()
as "inserted rate" and
metrics.document.inserted
as "inserted":
mongostat -o='host,mem,bits,metrics.document.inserted.rate()=inserted rate,metrics.document.inserted=inserted' --rowcount=5
The output would then resemble:
host mem.bits inserted rate inserted localhost:37017 64 501 3455 localhost:37017 64 967 13128 localhost:37017 64 972 22851 localhost:37017 64 214 25000 localhost:37017 64 0 25000
View Field Changes with .diff()

.diff()
returns the difference between the current
serverStatus
field value and the value from the previous
mongostat
call. The following example returns statistics on
the number of documents being inserted into a collection: inserted
diff
is the difference in the
metrics.document.inserted
field between subsequent
calls, while inserted
is the value of
metrics.document.inserted
:
mongostat -o='host,mem.bits,metrics.document.inserted.diff()=inserted diff,metrics.document.inserted=inserted' --rowcount=5
The output would then resemble:
host mem.bits inserted diff inserted localhost:27017 64 0 25359 localhost:27017 64 94 25453 localhost:27017 64 938 26391 localhost:27017 64 964 27355 localhost:27017 64 978 28333
View Statistics for a Replica Set or Sharded Cluster
In many cases, using the --discover
option
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
View Statistics in an Interactive Interface
Use the --interactive
option to
view statistics in a non-scrolling ncurses -style
interactive output. The --interactive
option lets you highlight specific
hosts, columns, or fields to view. When combined with --discover
,
--interactive
displays statistics for all members of a
replica set or sharded cluster, as in the following example:
mongostat --discover --interactive
The output for a sharded cluster would then resemble:
host insert query update delete getmore command dirty used flushes mapped vsize res faults qrw arw net_in net_out conn set repl time hostname.local:27018 *0 *0 *0 *0 0 1|0 0.0% 0.0% 0 3.25G 25.0M n/a 0|0 1|0 157b 43.9k 19 tic PRI Nov 2 11:44:46.439 hostname.local:27019 *0 *0 *0 *0 0 2|0 0.0% 0.0% 0 3.18G 26.0M n/a 0|0 1|0 322b 44.4k 12 tic SEC Nov 2 11:44:46.439 hostname.local:27020 *0 *0 *0 *0 0 2|0 0.0% 0.0% 0 3.18G 26.0M n/a 0|0 1|0 322b 44.4k 12 tic SEC Nov 2 11:44:46.439 hostname.local:27021 2017 *0 *0 *0 826 1029|0 0.0% 0.0% 0 3.25G 31.0M n/a 0|0 1|0 1.74m 1.60m 20 tac PRI Nov 2 11:44:46.439 hostname.local:27022 *2021 *0 *0 *0 0 2|0 0.0% 0.0% 0 3.19G 32.0M n/a 0|0 1|0 322b 44.6k 12 tac SEC Nov 2 11:44:46.438 hostname.local:27023 *2022 *0 *0 *0 0 3|0 0.0% 0.0% 0 3.19G 33.0M n/a 0|0 1|0 323b 44.7k 12 tac SEC Nov 2 11:44:46.438 localhost:27017 2071 *0 *0 *0 0 2073|0 0 0B 2.43G 9.00M 0 0|0 0|0 249k 130k 4 RTR Nov 2 11:44:47.429 Press '?' to toggle help
Connect to a MongoDB Atlas Cluster using AWS IAM Credentials
New in version 100.1.0.
To connect to a MongoDB Atlas cluster which
has been configured to support authentication via AWS IAM credentials,
provide a connection string
to
mongostat
similar to the following:
mongostat 'mongodb+srv://<aws access key id>:<aws secret access key>@cluster0.example.com/testdb?authSource=$external&authMechanism=MONGODB-AWS' <other options>
Connecting to Atlas using AWS IAM credentials in this manner uses the
MONGODB-AWS
authentication mechanism
and the $external
authSource
, as shown in this example.
If using an AWS session token,
as well, provide it with the AWS_SESSION_TOKEN
authMechanismProperties
value, as follows:
mongostat 'mongodb+srv://<aws access key id>:<aws secret access key>@cluster0.example.com/testdb?authSource=$external&authMechanism=MONGODB-AWS&authMechanismProperties=AWS_SESSION_TOKEN:<aws session token>' <other options>
Note
If the AWS access key ID, secret access key, or session token include the following characters:
: / ? # [ ] @
those characters must be converted using percent encoding.
Alternatively, the AWS access key ID, secret access key, and optionally
session token can each be provided outside of the connection string
using the --username
, --password
, and
--awsSessionToken
options instead, like so:
mongostat 'mongodb+srv://cluster0.example.com/testdb?authSource=$external&authMechanism=MONGODB-AWS' --username <aws access key id> --password <aws secret access key> --awsSessionToken <aws session token> <other options>
When provided as command line parameters, these three options do not require percent encoding.
You may also set these credentials on your platform using standard
AWS IAM environment variables.
mongostat
checks for the following environment variables when you
use the MONGODB-AWS
authentication mechanism
:
AWS_ACCESS_KEY_ID
AWS_SECRET_ACCESS_KEY
AWS_SESSION_TOKEN
If set, these credentials do not need to be specified in the connection string or via their explicit options.
Note
If you chose to use the AWS environment variables to specify these values, you cannot mix and match with the corresponding explicit or connection string options for these credentials. Either use the environment variables for access key ID and secret access key (and session token if used), or specify each of these using the explicit or connection string options instead.
The following example sets these environment variables in the bash
shell:
export AWS_ACCESS_KEY_ID='<aws access key id>' export AWS_SECRET_ACCESS_KEY='<aws secret access key>' export AWS_SESSION_TOKEN='<aws session token>'
Syntax for setting environment variables in other shells will be different. Consult the documentation for your platform for more information.
You can verify that these environment variables have been set with the following command:
env | grep AWS
Once set, the following example connects to a MongoDB Atlas cluster using these environment variables:
mongostat 'mongodb+srv://cluster0.example.com/testdb?authSource=$external&authMechanism=MONGODB-AWS' <other options>
Additional Information
For more information about monitoring MongoDB, see Monitoring for MongoDB.
For more background on other MongoDB status outputs see:
For an additional utility that provides MongoDB metrics see
mongotop
.