Monitor Azure Functions

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Alerts

Azure Monitor alerts proactively notify you when specific conditions are found in your monitoring data. Alerts allow you to identify and address issues in your system before your customers notice them. For more information, see Azure Monitor alerts.

There are many sources of common alerts for Azure resources. For examples of common alerts for Azure resources, see Sample log alert queries. The Azure Monitor Baseline Alerts (AMBA) site provides key alert metrics, dashboards, and guidelines for Azure Landing Zone (ALZ) scenarios.

The common alert schema standardizes the consumption of Azure Monitor alert notifications. For more information, see Common alert schema.

Types of alerts

You can alert on any metric or log data source in the Azure Monitor data platform. There are many different types of alerts depending on the services you're monitoring and the monitoring data you're collecting. Different types of alerts have various benefits and drawbacks. For more information, see Choose the right monitoring alert type.

The following list describes the types of Azure Monitor alerts you can create:

  • Metric alerts evaluate resource metrics at regular intervals. Metrics can be platform metrics, custom metrics, logs from Azure Monitor converted to metrics, or Application Insights metrics. Metric alerts can also apply multiple conditions and dynamic thresholds.
  • Log alerts allow users to use a Log Analytics query to evaluate resource logs at a predefined frequency.
  • Activity log alerts trigger when a new activity log event occurs that matches defined conditions. Resource Health alerts and Service Health alerts are activity log alerts that report on your service and resource health.

Some Azure services also support smart detection alerts, Prometheus alerts, or recommended alert rules.

For some services, you can monitor at scale by applying the same metric alert rule to multiple resources of the same type that exist in the same Azure region. Individual notifications are sent for each monitored resource. For supported Azure services and clouds, see Monitor multiple resources with one alert rule.

Insights

Some services in Azure have a built-in monitoring dashboard in the Azure portal that provides a starting point for monitoring your service. These dashboards are called insights, and you can find them in the Insights Hub of Azure Monitor in the Azure portal.

Application Insights

Azure Functions offers built-in integration with Application Insights to monitor functions executions. For detailed information about how to integrate, configure, and use Application Insights to monitor Azure Functions, see the following articles:

Resource types

Azure uses the concept of resource types and IDs to identify everything in a subscription. Azure Monitor similarly organizes core monitoring data into metrics and logs based on resource types, also called namespaces. Different metrics and logs are available for different resource types. Your service might be associated with more than one resource type.

Resource types are also part of the resource IDs for every resource running in Azure. For example, one resource type for a virtual machine is Microsoft.Compute/virtualMachines. For a list of services and their associated resource types, see Resource providers.

For more information about the resource types for Azure Functions, see Azure Functions monitoring data reference.

Data storage

For Azure Monitor:

  • Metrics data is stored in the Azure Monitor metrics database.
  • Log data is stored in the Azure Monitor logs store. Log Analytics is a tool in the Azure portal that can query this store.
  • The Azure activity log is a separate store with its own interface in the Azure portal.
  • You can optionally route metric and activity log data to the Azure Monitor logs database store so you can query the data and correlate it with other log data using Log Analytics.

For detailed information on how Azure Monitor stores data, see Azure Monitor data platform.

Azure Monitor platform metrics

Azure Monitor provides platform metrics for most services. These metrics are:

  • Individually defined for each namespace.
  • Stored in the Azure Monitor time-series metrics database.
  • Lightweight and capable of supporting near real-time alerting.
  • Used to track the performance of a resource over time.

Collection: Azure Monitor collects platform metrics automatically. No configuration is required.

Routing: You can also usually route platform metrics to Azure Monitor logs / Log Analytics so you can query them with other log data. For more information, see the Metrics diagnostic setting. For how to configure diagnostic settings for a service, see Create diagnostic settings in Azure Monitor.

For a list of all metrics it's possible to gather for all resources in Azure Monitor, see Supported metrics in Azure Monitor. For a list of available metrics for Azure Functions, see Azure Functions monitoring data reference.

Note

App Service metrics (Microsoft.Web/sites) aren't available when your function app runs on Linux in a Consumption plan.

Resource Logs aren't collected and stored until you create a diagnostic setting and route them to one or more locations.

Azure Functions integrates with Azure Monitor Logs to monitor functions. For detailed instructions on how to set up diagnostic settings to configure and route resource logs, see Create diagnostic settings in Azure Monitor.

Screenshot of adding a diagnostic setting for Azure Functions.

For the available resource log categories, their associated Log Analytics tables, and the logs schemas for Azure Functions, see Azure Functions monitoring data reference.

Azure Monitor resource logs

Resource logs provide insight into operations that were done by an Azure resource. Logs are generated automatically, but you must route them to Azure Monitor logs to save or query them. Logs are organized by category. A given namespace might have multiple resource log categories.

Collection: Resource logs aren't collected and stored until you create a diagnostic setting and route the logs to one or more locations. When you create a diagnostic setting, you specify which categories of logs to collect. There are multiple ways to create and maintain diagnostic settings, including the Azure portal, programmatically, and though Azure Policy.

Routing: The suggested default is to route resource logs to Azure Monitor Logs so you can query them with other log data. Other locations such as Azure Storage, Azure Event Hubs, and certain Microsoft monitoring partners are also available. For more information, see Azure resource logs and Resource log destinations.

For detailed information about collecting, storing, and routing resource logs, see Diagnostic settings in Azure Monitor.

For a list of all available resource log categories in Azure Monitor, see Supported resource logs in Azure Monitor.

All resource logs in Azure Monitor have the same header fields, followed by service-specific fields. The common schema is outlined in Azure Monitor resource log schema.

Other logs

Azure Functions also offers the ability to collect more than Azure Monitor resource logs. To view a near real time stream of application log files generated by your function running in Azure, you can connect to Application Insights and use Live Metrics Stream. Or, you can use the App Service platform built-in log streaming to view a stream of application log files. For more information, see Enable streaming execution logs in Azure Functions.

Analyze monitoring data

There are many tools for analyzing monitoring data.

Azure Monitor tools

Azure Monitor supports the following basic tools:

Tools that allow more complex visualization include:

  • Dashboards that let you combine different kinds of data into a single pane in the Azure portal.
  • Workbooks, customizable reports that you can create in the Azure portal. Workbooks can include text, metrics, and log queries.
  • Grafana, an open platform tool that excels in operational dashboards. You can use Grafana to create dashboards that include data from multiple sources other than Azure Monitor.
  • Power BI, a business analytics service that provides interactive visualizations across various data sources. You can configure Power BI to automatically import log data from Azure Monitor to take advantage of these visualizations.

Azure Monitor export tools

You can get data out of Azure Monitor into other tools by using the following methods:

To get started with the REST API for Azure Monitor, see Azure monitoring REST API walkthrough.

Analyze metrics for Azure Functions

The following examples use Azure Monitor metrics to help estimate the cost of running your function app on a Consumption plan. To learn more about estimating Consumption plan costs, see Estimating Consumption plan costs.

Use Azure Monitor metrics explorer to view cost-related data for your Consumption plan function apps in a graphical format.

  1. In the Azure portal, navigate to your function app.

  2. In the left panel, scroll down to Monitoring and choose Metrics.

  3. From Metric, choose Function Execution Count and Sum for Aggregation. This adds the sum of the execution counts during chosen period to the chart.

    Define a functions app metric to add to the chart

  4. Select Add metric and repeat steps 2-4 to add Function Execution Units to the chart.

The resulting chart contains the totals for both execution metrics in the chosen time range, which in this case is two hours.

Graph of function execution counts and execution units

As the number of execution units is so much greater than the execution count, the chart just shows execution units.

This chart shows a total of 1.11 billion Function Execution Units consumed in a two-hour period, measured in MB-milliseconds. To convert to GB-seconds, divide by 1024000. In this example, the function app consumed 1110000000 / 1024000 = 1083.98 GB-seconds. You can take this value and multiply by the current price of execution time on the Functions pricing page, which gives you the cost of these two hours, assuming you've already used any free grants of execution time.

Analyze logs for Azure Functions

Azure Functions writes all logs to the FunctionAppLogs table under LogManagement in the Log Analytics workspace where you send the data. You can use Kusto queries to query the data.

Screenshot of the Query window for Azure Functions in a Log Analytics workspace.

For a list of the tables used by Azure Monitor Logs and queryable by Log Analytics, see Monitoring Azure Functions data reference

The following sample queries can help you monitor all your functions app logs:


FunctionAppLogs
| order by TimeGenerated desc


FunctionAppLogs
| project TimeGenerated, HostInstanceId, Message, _ResourceId
| order by TimeGenerated desc

The following sample query can help you monitor a specific functions app's logs:

FunctionAppLogs
| where FunctionName == "<Function name>" 
| order by TimeGenerated desc

The following sample query can help you monitor exceptions on all your functions app logs:


FunctionAppLogs
| where ExceptionDetails != ""  
| order by TimeGenerated asc

The following sample query can help you monitor exceptions on a specific functions app's logs:

FunctionAppLogs
| where ExceptionDetails != ""  
| where FunctionName == "<Function name>" 
| order by TimeGenerated desc

Alerts

Azure Monitor alerts proactively notify you when important conditions are found in your monitoring data. They allow you to identify and address issues in your system before your customers notice them. You can set alerts on metrics, logs, and the activity log. Different types of alerts have benefits and drawbacks.

Azure Functions alert rules

The following table lists common and recommended alert rules for Azure Functions. These are just recommended alerts. You can set alerts for any metric, log entry, or activity log entry listed in the Monitoring data reference for Azure Functions.

Alert type Condition Description
Metric Average connections When number of connections exceed a set value
Metric HTTP 404 When HTTP 404 responses exceed a set value
Metric HTTP Server Errors When HTTP 5xx errors exceed a set value
Activity Log Create or update function app When app is created or updated
Activity Log Delete function app When app is deleted
Activity Log Restart function app When app is restarted
Activity Log Stop function app When app is stopped

Related content

For more information about monitoring Azure Functions, see the following articles: