---
title: Managing alert definitions
summary: null
url: >-
https://www.fastly.com/documentation/guides/observability/alerts/managing-alert-definitions
---
Alert definitions are configuration rules that determine when alerts are triggered and how notifications are handled. When creating an alert definition, you specify the [alert integrations](https://www.fastly.com/documentation/guides/observability/alerts/managing-alert-integrations) that should be used. Multiple alert definitions can use the same alert integration.
## Limitations and considerations
Keep the following things in mind:
- The maximum number of alert definitions that can exist at any one time per customer is 100. [Contact support](https://support.fastly.com) to discuss raising this limit.
- For observability metrics alerts, by default you can add alerts for [Historic Stats](https://www.fastly.com/documentation/reference/api/metrics-stats/historical-stats/). To add alerts for Origin Inspector and Domain Inspector metrics, you must purchase an [Observability package](https://docs.fastly.com/products/product-observability).
- Permissions to create and update observability metrics alert definitions are available to [superusers and engineers](https://www.fastly.com/documentation/guides/account-info/user-and-account-management/about-user-roles-and-permissions).
- Permissions to create and update audit log alert definitions are restricted to [superusers](https://www.fastly.com/documentation/guides/account-info/user-and-account-management/about-user-roles-and-permissions) only.
## Accessing alert definitions
To view a list of your alert definitions, follow these steps:
1. Log in to the [Fastly control panel](https://manage.fastly.com).
2. Go to **Observability** > **Alerts** > [**Definitions**](https://manage.fastly.com/observability/alerts/definitions). The Alert definitions page appears.
## Creating alert definitions
You can create observability metrics, alert definitions, and audit log alert definitions. The creation process for each starts from the Alert definitions page. Audit log alerts can also be created from the [Audit log](https://manage.fastly.com/account/audit-log) page.
### Observability metrics alert definitions
To create an observability metrics alert definition, start by picking the appropriate alert type and specifying the initial details:
1. Log in to the [Fastly control panel](https://manage.fastly.com).
2. Go to **Observability** > **Alerts** > [**Definitions**](https://manage.fastly.com/observability/alerts/definitions).
3. Click **Add alert definition**.
4. In the **Alert type** area, select **Observability metrics**.
5. Fill out the **Details** area as follows:
- In the **Name** field, enter a name for the alert.
- In the **Description** field, enter a description of what the alert tracks.
6. From the **Scope** controls, select the scope of the alert:
- Choose **All services (aggregated)** to monitor all your services.
- Choose **Single service** to monitor a specific service.
If you selected **Single service**, choose its data source:
1. From the **Service** menu, select a specific service.
2. From the **Data source** menu, select a data pipeline.
- Choose [`Historic Stats`](https://www.fastly.com/documentation/reference/api/metrics-stats/historical-stats/) to select historical stats to monitor.
- Choose [`Origin Inspector`](https://www.fastly.com/documentation/reference/api/metrics-stats/origin-inspector/) to select one or more origins to monitor.
- Choose [`Domain Inspector`](https://www.fastly.com/documentation/reference/api/metrics-stats/domain-inspector/) to select one or more domains to monitor.
After selecting all services or a single service to alert on, select the metric to monitor and the alert type for when that metric is observed:
1. From the **Metric** menu, select the metric to monitor.
2. From the **Alert type** controls, select **Threshold** to trigger the alert when the metric is above or below a threshold value, or **Percentage change** to trigger the alert when the metric increases by, decreases by, or increases or decreases by a percentage.
3. If you selected **Threshold** for the alert type, fill out the following fields:
- From the **Evaluation type** menu, select whether the alert should be triggered when the metric is above or below the threshold.
- In the **Threshold** field, enter the number that the metric must be above or below for the alert to trigger. You can also click and drag the threshold line on the graph to set this field.
- From the **Evaluation period** menu, select the number of minutes during which the observed metric is evaluated every minute to determine if the conditions have been met.
4. If you selected **Percentage change** for the alert type, fill out the following fields:
- From the **Evaluation type** menu, select whether the alert should be triggered when the metric increases by, decreases by, or increases or decreases by a percentage.
- In the **Percent** field, enter the percent that the metric must change for the alert to trigger.
- From the **Comparison period** menu, select the period during which the observed percentage is evaluated. The first and last minute of the period will be used to calculate the percentage.
- Optionally, from the **Excluded values** menu, select the values that should be disregarded and not used to trigger the alert.
Finally, select the integration that should receive the alert you've defined:
1. In the **Notifications** area, from the **Integrations** menu, select one or more integrations to receive alert notifications. If you haven't created an integration yet, click **create an integration** to set one up.
2. Click **Save Alert**.
The alert appears on the Alert definitions page and begins evaluating immediately.
### Audit log alert definitions
To create an audit log alert definition, follow these steps:
1. Log in to the [Fastly control panel](https://manage.fastly.com).
2. Go to **Observability** > **Alerts** > [**Definitions**](https://manage.fastly.com/observability/alerts/definitions).
3. Click **Add alert definition**.
4. In the **Alert type** area, select **Audit log activity**.
5. Fill out the **Details** area as follows:
- In the **Name** field, enter a name for the alert.
- In the **Description** field, enter a description of what the alert tracks.
6. From the **Audit log activity type** menu, select the activity type to monitor. Options include `Account`, `Next-Gen WAF`, `CDN`, and `Compute`.
7. From the **Event types** menu, select one or more event types to monitor.
8. Depending on which audit log activity type you selected additional controls may appear. Do one of the following:
- For `CDN`, select **Any CDN service** to alert when an event occurs on any CDN service, or **Specific CDN services** to alert only when an event occurs on selected services. If you select **Specific CDN services**, from the **CDN services** menu, select one or more services.
- For `Compute`, select **Any Compute service** to alert when an event occurs on any Compute service, or **Specific Compute services** to alert only when an event occurs on selected services. If you select **Specific Compute services**, from the **Compute services** menu, select one or more services.
- For `Next-Gen WAF`, select **Any workspace** to alert when an event occurs on any workspace, or **Specific workspaces** to alert only when an event occurs on selected workspaces. If you select **Specific workspaces**, from the **Workspaces** menu, select one or more workspaces.
9. In the **Notifications** area, from the **Integrations** menu, select one or more integrations to receive alert notifications. If you haven't created an integration yet, click **create an integration** to set one up.
10. Click **Create audit log alert**. The alert appears on the Alert definitions page and begins evaluating immediately.
> **HINT:** You can also start creating an audit log alert from the [Audit log](https://manage.fastly.com/account/audit-log) page by clicking **Add alert definition**.
## Editing alert definitions
You can edit observability metrics, alert definitions, and audit log alert definitions from the Alert definitions page.
### Editing observability metrics alert definitions
To edit an observability metrics alert definition, follow these steps:
1. Log in to the [Fastly control panel](https://manage.fastly.com).
2. Go to **Observability** > **Alerts** > [**Definitions**](https://manage.fastly.com/observability/alerts/definitions).
3. Click the pencil 
to the right of the alert definition that you want to edit.
4. Update the alert definition fields. For field descriptions, check out [Observability metrics alert definitions](https://www.fastly.com/documentation/guides/observability/alerts/managing-alert-definitions#observability-metrics-alert-definitions) above.
5. Click **Save Alert**. The updated alert definition appears on the Alert definitions page.
You can also edit an observability metrics alert definition from the alert details page. On the [Alerts Overview](https://manage.fastly.com/observability/alerts) page, click a firing or resolved alert to open its details page, then click **Edit alert definition**.
### Editing audit log alert definitions
To edit an audit log alert definition, follow these steps:
1. Log in to the [Fastly control panel](https://manage.fastly.com).
2. Go to **Observability** > **Alerts** > [**Definitions**](https://manage.fastly.com/observability/alerts/definitions).
3. Click the pencil to the right of the alert definition that you want to edit.
4. Update the alert definition fields. For field descriptions, check out [Audit log alert definitions](https://www.fastly.com/documentation/guides/observability/alerts/managing-alert-definitions#audit-log-alert-definitions) above.
5. Click **Save Alert**. The updated alert definition appears on the Alert definitions page.
## Deleting alert definitions
From the [Alert definitions](https://manage.fastly.com/observability/alerts/definitions) page, you can delete alert definitions by clicking the trash 
to the right of the alert definition that you want to delete. The alert definition is removed from the Alert definitions page.