[[configuration-metricbeat]]
== Specify which modules to run

Metricbeat provides a couple different ways to enable modules and metricsets:

* <<enable-modules-d-configs>>
* <<enable-modules-config-file>>

include::../../libbeat/docs/shared-note-file-permissions.asciidoc[]

[float]
[[enable-modules-d-configs]]
=== Enable module configs in the `modules.d` directory

The `modules.d` directory contains default configurations for all the modules
available in Metricbeat. You can enable or disable specific module
configurations  under `modules.d` by running the <<modules-command,`modules
enable` or `modules disable`>> commands.

For example, to enable the `apache` and `mysql` configs in the `modules.d`
directory, you use:

[source,shell]
----
./metricbeat modules enable apache mysql
----

Then when you run Metricbeat, it loads the corresponding module configurations
specified in the `modules.d` directory (for example, `modules.d/apache.yml` and
`modules.d/mysql.yml`).

To see a list of enabled and disabled modules, run:

[source,shell]
----
./metricbeat modules list
----

You can change the default module configurations by modifying the `.yml` files
in the `modules.d` directory. 

The following example shows a basic configuration for the Apache module:

[source,yaml]
----
- module: apache
  metricsets: ["status"]
  hosts: ["http://127.0.0.1/"]
  period: 10s
  fields:
    dc: west
  tags: ["tag"]
  processors:
  ....
----


See <<config-combos>> for additional configuration examples.

[float]
[[enable-modules-config-file]]
=== Enable module configs in the +{beatname_lc}.yml+ file


When possible, you should use the config files in the `modules.d` directory.

However, enabling modules directly in the config file is a practical approach if
you have upgraded from a previous version of {beatname_uc} and don't want to
move your module configs to the `modules.d` directory. You can continue to
configure modules in the +{beatname_lc}.yml+ file, but you won't be able to use
the `modules` command to enable and disable configurations because the command
requires the `modules.d` layout.

To enable specific modules and metricsets in the +{beatname_lc}.yml+ config
file, you can add entries to the +{beatname_lc}.modules+ list. Each entry in the
list begins with a dash (-) and is followed by settings for that module. 

The following example shows a configuration where the apache and mysql modules
are enabled:

[source,yaml]
------------------------------------------------------------------------------
metricbeat.modules:

#---------------------------- Apache Status Module ---------------------------
- module: apache
  metricsets: ["status"]
  period: 1s
  hosts: ["http://127.0.0.1/"]

#---------------------------- MySQL Status Module ----------------------------
- module: mysql
  metricsets: ["status"]
  period: 2s
  hosts: ["root@tcp(127.0.0.1:3306)/"]
------------------------------------------------------------------------------

In the following example, the Redis host is crawled for `stats` information
every second because this is critical data, but the full list of Apache
metricsets is only fetched every 30 seconds because the metrics are less
critical.

[source,yaml]
----
metricbeat.modules:
- module: redis
  metricsets: ["info"]
  hosts: ["host1"]
  period: 1s
- module: apache
  metricsets: ["info"]
  hosts: ["host1"]
  period: 30s
----

[float]
[[config-combos]]
== Configuration combinations

You can specify a module configuration that uses different combinations of
metricsets, periods, and hosts. 

For a module with multiple metricsets defined, it's possible to define the
module twice and specify a different period to use for each metricset. For the
following example, the `set1` metricset will be fetched every 10 seconds, while
the `set2` metricset will be fetched every 2 minutes:

[source,yaml]
----
- module: example
  metricsets: ["set1"]
  hosts: ["host1"]
  period: 10s
- module: example
  metricsets: ["set2"]
  hosts: ["host1"]
  period: 2m
----


[float]
=== Standard config options

You can specify the following options for any Metricbeat module. Some modules
require additional configuration settings. See the <<metricbeat-modules>>
section for more information.

[float]
==== `module`

The name of the module to run. For documentation about each module, see the
<<metricbeat-modules>> section.

[float]
==== `metricsets`

A list of metricsets to execute. Make sure that you only list metricsets that
are available in the module. It is not possible to reference metricsets from
other modules. For a list of available metricsets, see the documentation for the
module.

[float]
==== `enabled`

A Boolean value that specifies whether the module is enabled. If you use the
default config file, `metricbeat.yml`, the System module is enabled (set to
`enabled: true`) by default. If the `enabled` option is missing from the
configuration block, the module is enabled by default.

[float]
[[metricset-period]]
==== `period`

How often the metricsets are executed. If a system is not reachable, Metricbeat
returns an error for each period. This setting is required.

[float]
==== `hosts`

A list of hosts to fetch information from. For some metricsets, such as the
System module, this setting is optional.

[float]
==== `fields`

A dictionary of fields that will be sent with the metricset event. This setting
is optional.

[float]
==== `tags`

A list of tags that will be sent with the metricset event. This setting is
optional.

[float]
==== `processors`

A list of processors to apply to the data generated by the metricset.

See <<filtering-and-enhancing-data>> for information about specifying
processors in your config.

