# AWS::Route53RecoveryControl::SafetyRule GatingRule

A gating rule verifies that a set of gating controls evaluates as true, based on a rule configuration that you specify. If the gating rule evaluates to true, Amazon Route 53 Application Recovery Controller allows a set of routing control state changes to run and complete against the set of target controls.

## Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

### JSON

<pre>
{
    "<a href="#gatingcontrols" title="GatingControls">GatingControls</a>" : <i>[ String, ... ]</i>,
    "<a href="#targetcontrols" title="TargetControls">TargetControls</a>" : <i>[ String, ... ]</i>,
    "<a href="#waitperiodms" title="WaitPeriodMs">WaitPeriodMs</a>" : <i>Integer</i>
}
</pre>

### YAML

<pre>
<a href="#gatingcontrols" title="GatingControls">GatingControls</a>: <i>
      - String</i>
<a href="#targetcontrols" title="TargetControls">TargetControls</a>: <i>
      - String</i>
<a href="#waitperiodms" title="WaitPeriodMs">WaitPeriodMs</a>: <i>Integer</i>
</pre>

## Properties

#### GatingControls

The gating controls for the gating rule. That is, routing controls that are evaluated by the rule configuration that you specify.

_Required_: Yes

_Type_: List of String

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

#### TargetControls

Routing controls that can only be set or unset if the specified RuleConfig evaluates to true for the specified GatingControls. For example, say you have three gating controls, one for each of three AWS Regions. Now you specify AtLeast 2 as your RuleConfig. With these settings, you can only change (set or unset) the routing controls that you have specified as TargetControls if that rule evaluates to true. 
In other words, your ability to change the routing controls that you have specified as TargetControls is gated by the rule that you set for the routing controls in GatingControls.

_Required_: Yes

_Type_: List of String

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

#### WaitPeriodMs

An evaluation period, in milliseconds (ms), during which any request against the target routing controls will fail. This helps prevent "flapping" of state. The wait period is 5000 ms by default, but you can choose a custom value.

_Required_: No

_Type_: Integer

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)