# Managing alarms
<a name="Manage-CloudWatch-Alarm"></a>

**Topics**
+ [Edit or delete a CloudWatch alarm](Edit-CloudWatch-Alarm.md)
+ [Hide Auto Scaling alarms](hide-autoscaling-alarms.md)
+ [Alarms and tagging](CloudWatch_alarms_and_tagging.md)
+ [Viewing and managing muted alarms](viewing-managing-muted-alarms.md)

# Edit or delete a CloudWatch alarm
<a name="Edit-CloudWatch-Alarm"></a>

You can edit or delete an existing alarm.

You can't change the name of an existing alarm. You can copy an alarm and give the new alarm a different name. To copy an alarm, select the check box next to the alarm name in the alarm list and choose **Action**, **Copy**.

**To edit an alarm**

1. Open the CloudWatch console at [https://console.aws.amazon.com/cloudwatch/](https://console.aws.amazon.com/cloudwatch/).

1. In the navigation pane, choose **Alarms**, **All Alarms**.

1. Choose the name of the alarm.

1. To add or remove tags, choose the **Tags** tab and then choose **Manage tags**.

1. To edit other parts of the alarm, choose **Actions**, **Edit**.

   The **Specify metric and conditions** page appears, showing a graph and other information about the metric and statistic that you selected.

1. To change the metric, choose **Edit**, choose the **All metrics** tab, and do one of the following:
   + Choose the service namespace that contains the metric that you want. Continue choosing options as they appear to narrow the choices. When a list of metrics appears, select the check box next to the metric that you want.
   + In the search box, enter the name of a metric, dimension, or resource ID and press Enter. Then choose one of the results and continue until a list of metrics appears. Select the check box next to the metric that you want. 

   Choose **Select metric**.

1. To change other aspects of the alarm, choose the appropriate options. To change how many data points must be breaching for the alarm to go into `ALARM` state or to change how missing data is treated, choose **Additional configuration**.

1. Choose **Next**.

1. Under **Notification**, **Auto Scaling action**, and **EC2 action**, optionally edit the actions taken when the alarm is triggered. Then choose **Next**.

1. Optionally change the alarm description.

   You can't change the name of an existing alarm. You can copy an alarm and give the new alarm a different name. To copy an alarm, select the check box next to the alarm name in the alarm list and choose **Action**, **Copy**.

1. Choose **Next**.

1. Under **Preview and create**, confirm that the information and conditions are what you want, then choose **Update alarm**.

**To update an email notification list that was created using the Amazon SNS console**

1. Open the Amazon SNS console at [https://console.aws.amazon.com/sns/v3/home](https://console.aws.amazon.com/sns/v3/home).

1. In the navigation pane, choose **Topics** and then select the ARN for your notification list (topic).

1. Do one of the following:
   + To add an email address, choose **Create subscription**. For **Protocol**, choose **Email**. For **Endpoint**, enter the email address of the new recipient. Choose **Create subscription**.
   + To remove an email address, choose the **Subscription ID**. Choose **Other subscription actions**, **Delete subscriptions**.

1. Choose **Publish to topic**.

**To delete an alarm**

1. Open the CloudWatch console at [https://console.aws.amazon.com/cloudwatch/](https://console.aws.amazon.com/cloudwatch/).

1. In the navigation pane, choose **Alarms**.

1. Select the check box to the left of the name of the alarm, and choose **Actions**, **Delete**.

1. Choose **Delete**.

# Hide Auto Scaling alarms
<a name="hide-autoscaling-alarms"></a>

When you view your alarms in the AWS Management Console, you can hide the alarms related to both Amazon EC2 Auto Scaling and Application Auto Scaling. This feature is available only in the AWS Management Console.

**To temporarily hide Auto Scaling alarms**

1. Open the CloudWatch console at [https://console.aws.amazon.com/cloudwatch/](https://console.aws.amazon.com/cloudwatch/).

1. In the navigation pane, choose **Alarms**, **All alarms**, and select **Hide Auto Scaling alarms**.

# Alarms and tagging
<a name="CloudWatch_alarms_and_tagging"></a>

*Tags* are key-value pairs that can help you organize and categorize your resources. You can also use them to scope user permissions by granting a user permission to access or change only resources with certain tag values. For more general information about tagging resources, see [ Tagging your AWS resources](https://docs.aws.amazon.com/tag-editor/latest/userguide/tagging.html)

The following list explains some details about how tagging works with CloudWatch alarms.
+ To be able to set or update tags for a CloudWatch resource, you must be signed on to an account that has the `cloudwatch:TagResource` permission. For example, to create an alarm and set tags for it, you must have the `cloudwatch:TagResource` permission in addition to the `the cloudwatch:PutMetricAlarm ` permission. We recommend that you make sure anyone in your organization who will create or update CloudWatch resources has the `cloudwatch:TagResource` permission.
+ Tags can be used for tag-based authorization control. For example, IAM user or role permissions can include conditions to limit CloudWatch calls to specific resources based on their tags. However, keep in mind the following
  + Tags with names that start with `aws:` can't be used for tag-based authorization control.
  + Composite alarms do not support tag-based authorization control.

# Viewing and managing muted alarms
<a name="viewing-managing-muted-alarms"></a>

 **Viewing muted alarms:** You can easily identify which alarms are currently muted through the CloudWatch console. In both the alarms list view and individual alarm detail pages, a mute icon appears next to alarms whose actions are currently being muted by active mute rules. This visual indicator helps you quickly understand which alarms actions are being currently muted until the mute window expires. 

![\[alt text not found\]](http://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/images/alarm_mute_rules_icon.png)


 **Alarms timeline:** The CloudWatch alarms console provides a comprehensive timeline view that shows when your alarm actions were muted. This timeline displays mute periods alongside alarm state changes, giving you a complete historical view of both alarm behaviour and muting activity. You can use this timeline to analyze the effectiveness of your mute rules and understand how they correlate with your operational activities. 

![\[alt text not found\]](http://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/images/alarm-mutes-timelineview.png)


 **Programmatically checking alarm mute status:** To programmatically determine if an alarm is currently muted, you can use the [ListAlarmMuteRules](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_ListAlarmMuteRules.html) API with the alarm name as a filter criteria. This API returns all active mute rules that are affecting the specified alarm, allowing you to integrate mute status checks into your automation workflows, monitoring dashboards, or operational tools. 

 For example: To check if an alarm named "HighCPUAlarm" is currently muted, call the [ListAlarmMuteRules](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_ListAlarmMuteRules.html) API with the filter parameter set to the alarm name. The response will include all mute rules targeting that alarm, along with their current status (SCHEDULED, ACTIVE, or EXPIRED). 

 **Alarm history:** Whenever alarm actions are muted due to an active mute rule, CloudWatch writes a history entry to the alarm's history log. This provides a complete audit trail of when your alarms were muted, helping you understand the timeline of muting events and correlate them with operational activities. You can view this history through the CloudWatch console or retrieve it programmatically using the [DescribeAlarmHistory](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_DescribeAlarmHistory.html) API. 

**Note**  
 When multiple alarm mute rules are active simultaneously, the most recently created mute rule name is written to the alarm history along with the total number of other active mute rules. 
 The timeline displays mute periods only when an alarm state transitions during an active mute window and actions were prevented from executing. 

**Tip**  
 You can manage alarm mute rules programmatically using the CloudWatch API. For more information, see [PutAlarmMuteRule](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_PutAlarmMuteRule.html), [GetAlarmMuteRule](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_GetAlarmMuteRule.html), [ListAlarmMuteRules](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_ListAlarmMuteRules.html), and [DeleteAlarmMuteRule](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_DeleteAlarmMuteRule.html).