NAME¶
mongostat - MongoDB
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
/administration/monitoring.
For more 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 "
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¶
- --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
- Returns the version of the mongostat utility.
- --host <hostname><:port>
- Specifies a resolvable hostname for the mongod from
which you want to export data. By default mongostat attempts to
connect to a MongoDB instance 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 mongostat --host command.
- --ipv6
- Enables IPv6 support that 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 2.4: MongoDB added support for SSL
connections to mongod instances in mongostat.
- Note
- SSL support in mongostat is not compiled into the default
distribution of MongoDB. See /administration/ssl for more
information on SSL and MongoDB.
Additionally, mongostat does not support connections to mongod
instances that require client certificate validation.
Allows
mongostat to connect to
mongod instance over an SSL
connection.
- --username <username>, -u
<username>
- Specifies a username to authenticate to the MongoDB
instance, if your database requires authentication. Use in conjunction
with the mongostat --password option to supply a password.
- --password <password>, -p
<password>
- Specifies a password to authenticate to the MongoDB
instance. Use in conjunction with the mongostat --username option
to supply a username.
If you specify a --username without the --password option,
mongostat 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, mongostat 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,
mongostat also includes support for GSSAPI to handle
Kerberos authentication.
See /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 <number>
- 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
- With this option mongostat 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.
- --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.
- 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 node.
|
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¶
2011-2013, 10gen, Inc.