Azure Functions monitoring data reference

Article
08/21/2024

This reference applies to the use of Azure Monitor for monitoring function apps hosted in Azure Functions. See Monitoring function app with Azure Monitor for details on using Azure Monitor to collect and analyze monitoring data from your function apps.

See Monitor Azure Functions for details on the data you can collect for Azure Functions and how to use it.

See Monitor executions in Azure Functions for details on using Application Insights to collect and analyze log data from individual functions in your function app.

Azure Functions specific metrics

There are two metrics that are of specific interest to function apps:

Hosting plans that allow your apps to scale dynamically support extra Functions-specific metrics:

Consumption plan
Flex Consumption plan

These metrics are used specifically when estimating Consumption plan costs.

Metric	Description
FunctionExecutionCount	Function execution count indicates the number of times your function app executed. This value correlates to the number of times a function runs in your app. This metric isn't currently supported for Premium and Dedicated (App Service) plans running on Linux.
FunctionExecutionUnits	Function execution units are a combination of execution time and your memory usage. Memory data isn't a metric currently available through Azure Monitor. However, if you want to optimize the memory usage of your app, can use the performance counter data collected by Application Insights. This metric isn't currently supported for Premium and Dedicated (App Service) plans running on Linux.

These metrics are used to estimate the costs associated with on demand and always ready meters used for billing in a [Flex Consumption plan]:

Metric	Description	Meter calculation
OnDemandFunctionExecutionCount	Total number of function executions in on demand instances.	`OnDemandFunctionExecutionCount / 10` is the On Demand Total Executions meter, for which the unit of measurement is in tens.
AlwaysReadyFunctionExecutionCount	Total number of function executions in always ready instances.	`AlwaysReadyFunctionExecutionCount / 10` is the Always Ready Total Executions meter, for which the unit of measurement is in tens.
OnDemandFunctionExecutionUnits	Total MB-millseconds from on demand instances while actively executing functions.	`OnDemandFunctionExecutionUnits / 1,024,000` is the On Demand Execution Time meter, in GB-seconds.
AlwaysReadyFunctionExecutionUnits	Total MB-millseconds from always ready instances while actively executing functions.	`AlwaysReadyFunctionExecutionUnits / 1,024,000` is the Always Ready Execution Time meter, in GB-seconds.
AlwaysReadyUnits	The total MB-millseconds of always ready instances assigned to the app, whether or not functions are actively executing.	`AlwaysReadyUnits / 1,024,000` is the Always Ready Baseline meter, in GB-seconds.

In this table, all execution units are calculated by multipling the fixed instance memory size, such as 2,048 MB or 4,096 MB, by total execution times, in milliseconds.

Supported metrics for Microsoft.Web/sites

The following table lists the metrics available for the Microsoft.Web/sites resource type. Most of these metrics apply to both function app and web apps, which both run on App Service.

Note

These metrics aren't available when your function app runs on Linux in a Consumption plan.

Table headings

Metric - The metric display name as it appears in the Azure portal.
Name in Rest API - Metric name as referred to in the REST API.
Unit - Unit of measure.
Aggregation - The default aggregation type. Valid values: Average, Minimum, Maximum, Total, Count.
Dimensions - Dimensions available for the metric.
Time Grains - Intervals at which the metric is sampled. For example, PT1M indicates that the metric is sampled every minute, PT30M every 30 minutes, PT1H every hour, and so on.
DS Export- Whether the metric is exportable to Azure Monitor Logs via Diagnostic Settings. For information on exporting metrics, see Create diagnostic settings in Azure Monitor.

Metric dimensions

For information about what metric dimensions are, see Multi-dimensional metrics.

Azure Functions doesn't have any metrics that contain dimensions.

Resource logs

This section lists the types of resource logs you can collect for this service. The section pulls from the list of all resource logs category types supported in Azure Monitor.

Supported resource logs for Microsoft.Web/sites

The log specific to Azure Functions is FunctionAppLogs.

For more information, see the App Service monitoring data reference.

Azure Monitor Logs tables

This section refers to all of the Azure Monitor Logs tables relevant to this service, which are available for query by Log Analytics using Kusto queries.

This service uses the listed tables to store resource log data. The following columns are relevant.

App Services

Microsoft.Web/sites

FunctionAppLogs

Activity log

The linked table lists the operations that may be recorded in the activity log for this service. This is a subset of all the possible resource provider operations in the activity log.

For more information on the schema of activity log entries, see Activity Log schema.

The following table lists operations related to Azure Functions that might be created in the activity log.

Operation	Description
Microsoft.web/sites/functions/listkeys/action	Return the keys for the function.
Microsoft.Web/sites/host/listkeys/action	Return the host keys for the function app.
Microsoft.Web/sites/host/sync/action	Sync triggers operation.
Microsoft.Web/sites/start/action	Function app started.
Microsoft.Web/sites/stop/action	Function app stopped.
Microsoft.Web/sites/write	Change a function app setting, such as runtime version or enable remote debugging.

You may also find logged operations that relate to the underlying App Service behaviors. For a more complete list, see Microsoft.Web resource provider operations.

See Monitor Azure Functions for a description of monitoring Azure Functions.
See Monitor Azure resources with Azure Monitor for details on monitoring Azure resources.