[role="xpack"]
[testenv="enterprise"]
[[autoscaling-proactive-storage-decider]]
=== Proactive storage decider

The proactive storage decider (`proactive_storage`) calculates the storage required to contain
the current data set plus an estimated amount of expected additional data.

The proactive storage decider is enabled for all policies governing nodes with the `data_hot` role.

The estimation of expected additional data is based on past indexing that
occurred within the `forecast_window`.
Only indexing into data streams contributes to the estimate.

[[autoscaling-proactive-storage-decider-settings]]
==== Configuration settings

`forecast_window`::
(Optional, <<time-units,time value>>)
The window of time to use for forecasting. Defaults to 30 minutes.

[[autoscaling-proactive-storage-decider-examples]]
==== {api-examples-title}

This example puts an autoscaling policy named `my_autoscaling_policy`, overriding
the proactive decider's `forecast_window` to be 10 minutes.

[source,console]
--------------------------------------------------
PUT /_autoscaling/policy/my_autoscaling_policy
{
  "roles" : [ "data_hot" ],
  "deciders": {
    "proactive_storage": {
      "forecast_window": "10m"
    }
  }
}
--------------------------------------------------
// TEST

The API returns the following result:

[source,console-result]
--------------------------------------------------
{
  "acknowledged": true
}
--------------------------------------------------

//////////////////////////

[source,console]
--------------------------------------------------
DELETE /_autoscaling/policy/my_autoscaling_policy
--------------------------------------------------
// TEST[continued]

//////////////////////////
