Create and configure signals in Azure Monitor health models (preview)

Signals determine the health of entities in Azure Monitor health models. This article explains how to configure and tune signals in the designer.

Signal types

Each entity in a health model can use any of the available signal types described in the following table.

Configure signals in the designer

The Signals tab of the entity editor allows you to create or edit signals and assign them to the entity. If a data source is defined for the entity, then you can configure its details. If not, then you're given an option to enable and configure that type.

When you add a data source to an entity, you must specify the following properties. You can change these properties later.

To modify the data source configuration and save the entity, your user identity needs at least Reader access to the target Azure resource. Otherwise, the UI shows an error: "The associated Azure resource was not found. It might not exist, or you don't have access to it."

Add signal assignment

When you select Add metric/log query/Prometheus signal in the entity editor, you have multiple options.

Signal details

The details required for each signal will vary depending on its type.

ContainerLogV2
| where _ResourceId == '/subscriptions/00000000-0000-0000-0000-000000000000/resourcegroups/my-resource-group/providers/microsoft.containerservice/managedclusters/my-cluster'
| where LogSource == 'stderr'
| summarize value = count()

Query templates

Both Log Analytics and Azure Monitor workspace signals support a predefined set of template strings. Use templates within string literals in your queries. The health model dynamically replaces them when running signal evaluation.

The following table lists all supported template strings.

The following example shows a Log Analytics query that uses a template string:

ContainerLogV2
| where _ResourceId == '{{entity.azureResourceId}}'
| where LogSource == 'stderr'
| summarize value = count()

Use any template in either query type. For example, you can reference {{entity.azureResourceId}} or {{entity.azureMonitorWorkspaceResourceId}} in a log signal query.

Signal definitions are a common use case for query templates. Create a signal definition that uses a query template, and apply it to multiple entities. The signal uses each entity’s context during evaluation, so you don’t need to adjust the query manually.

Azure Resource Health signals

Azure Resource Health signals use Azure platform health information as a signal on an entity. This signal surfaces whether resource availability or platform-reported issues are contributing to the entity's health state, alongside the metric and query signals that you define.

Add an Azure Resource Health signal from the Signals tab of the entity editor, under the entity's Azure resource data source. For more information about the underlying status, see Azure Resource Health overview.

Azure Resource Health isn't supported by every resource type. The setting can be disabled for Azure resources that don't support Resource Health.

Thresholds

Thresholds are numeric values that you compare to the value of the signal to determine its health state. Each signal definition has two thresholds, one for the Degraded state and one for the Unhealthy state. The degraded threshold is optional, but the unhealthy threshold is required.

Specify the operator for each threshold to determine how the signal value is compared. Some signals indicate a degraded or unhealthy state when the value is above the threshold, while others indicate a degraded or unhealthy state when the value is below the threshold.

To define both thresholds for a signal definition ensure that degraded threshold is set to a value that is less than the unhealthy threshold. The degraded state will be set if the signal value is between the degraded and unhealthy thresholds. If the signal value is above the unhealthy threshold, then the entity is set to the unhealthy state. If the signal value is below the degraded threshold, then the entity is set to the healthy state.

Signal definitions

Instead of creating a new signal for each entity, you can define a signal once and reuse it across multiple entities by creating a signal definition. Signal definitions are reusable configurations that define a specific signal and its associated thresholds.

To create a signal definition, select Save as new signal definition when editing a signal instead of Add to entity.

Signal definitions are displayed along with other signals for an entity, but have a unique icon to distinguish them from other signals.

To add a signal definition to another entity, select Signal definitions to choose from the available signal definitions.

Edit signal definitions in the designer as you would edit any other signal. When you edit the signal definition for one entity, the changes will be applied to all entities that use that signal definition. You might use the same metric to measure the health of multiple entities, but different entities might require different thresholds. In this case, create multiple signal definitions with different thresholds.

The Signal definitions view lists all of the signal definitions in the health model. Select any signal definition to view its details, including the entities that use it.

To delete a signal definition, open the signal definitions view, select any signal definitions to delete, and select Delete at the top of the screen. This button is disabled if any of the selected signals are in use by an entity in the health model.

Signal grouping

Organize signals into aggregation groups to control health-state evaluation. Signal groups use aggregation rules to calculate a group health state, which contributes to the health state of the entity.

• All signal types can be added to any group.
• A signal can be a member of multiple groups.
• Ungrouped signals contribute directly to the entity's health state.

Example

The following example contains an entity with four signals of different types and two signal groups.

• Signal 1 is ungrouped and Healthy.
• Group 1 uses Healthy limit aggregation with Absolute values, a degraded threshold of 1, and an unhealthy threshold of 0. Its health state is Degraded.
  • Signal 2 is Degraded.
  • Signal 3 is Healthy.
  • Signal 4 is Unhealthy.
• Group 2 uses Worst of aggregation. Its health state is Healthy.
  • Signal 3 is Healthy and is also a member of Group 1.

Group 1 has one healthy signal out of three. The healthy signal count meets the degraded threshold of 1 but stays above the unhealthy threshold of 0, so the group is degraded. Because Group 1 is degraded, the entity's overall health state is Degraded.

Set up

To configure your first signal group:

1. Go to the entity editor in the designer.
2. Configure data sources.
3. In the Signals section, select Signal grouping.
4. Select Create signal group.
5. Configure Display name and Aggregation type.
6. Select Save.

The new signal group appears in the signal list. You can now add signals to it. To add signals to the group:

1. Select one or more signals. If the entity has no signals, add a signal first. You can select a signal that's already in a group.
2. Select Signal grouping.
3. Select Add selected signals to group, and then select a group from the list.

To remove a signal from a group:

1. Select the signals that you want to remove from a group.
2. Select Signal grouping.
3. Select Remove from group.

Removing a signal from a group doesn't remove it from the entity.

Configuration options

The following table describes the options for configuring a signal group.

Next steps

• Configure a health model using the designer
• Configure alerts in health models
• Analyze health state of the health model and its entities