This is the new *Amazon CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [Amazon CloudFormation User Guide](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::CloudWatch::Alarm Metric
<a name="aws-properties-cloudwatch-alarm-metric"></a>

The `Metric` property type represents a specific metric. `Metric` is a property of the [MetricStat](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/aws-properties-cloudwatch-alarm-metricstat.html) property type.

## Syntax
<a name="aws-properties-cloudwatch-alarm-metric-syntax"></a>

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

### JSON
<a name="aws-properties-cloudwatch-alarm-metric-syntax.json"></a>

```
{
  "[Dimensions](#cfn-cloudwatch-alarm-metric-dimensions)" : [ Dimension, ... ],
  "[MetricName](#cfn-cloudwatch-alarm-metric-metricname)" : String,
  "[Namespace](#cfn-cloudwatch-alarm-metric-namespace)" : String
}
```

### YAML
<a name="aws-properties-cloudwatch-alarm-metric-syntax.yaml"></a>

```
  [Dimensions](#cfn-cloudwatch-alarm-metric-dimensions): 
    - Dimension
  [MetricName](#cfn-cloudwatch-alarm-metric-metricname): String
  [Namespace](#cfn-cloudwatch-alarm-metric-namespace): String
```

## Properties
<a name="aws-properties-cloudwatch-alarm-metric-properties"></a>

`Dimensions`  <a name="cfn-cloudwatch-alarm-metric-dimensions"></a>
The metric dimensions that you want to be used for the metric that the alarm will watch.  
*Required*: No  
*Type*: Array of [Dimension](aws-properties-cloudwatch-alarm-dimension.md)  
*Maximum*: `30`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`MetricName`  <a name="cfn-cloudwatch-alarm-metric-metricname"></a>
The name of the metric that you want the alarm to watch. This is a required field.  
*Required*: No  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `255`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Namespace`  <a name="cfn-cloudwatch-alarm-metric-namespace"></a>
The namespace of the metric that the alarm will watch.  
*Required*: No  
*Type*: String  
*Pattern*: `[^:].*`  
*Minimum*: `1`  
*Maximum*: `255`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)