Application Monitoring for Azure App Service and Node.js

Monitoring of your Node.js web applications running on Azure App Services doesn't require any modifications to the code. This article walks you through enabling Azure Monitor Application Insights monitoring and provides preliminary guidance for automating the process for large-scale deployments.

Enable Application Insights

The easiest way to enable application monitoring for Node.js applications running on Azure App Services is through Azure portal. Turning on application monitoring in Azure portal will automatically instrument your application with Application Insights, and doesn't require any code changes.

Autoinstrumentation through Azure portal

For a complete list of supported autoinstrumentation scenarios, see Supported environments, languages, and resource providers.

You can turn on monitoring for your Node.js apps running in Azure App Service just with one click, no code change required. Application Insights for Node.js is integrated with Azure App Service on Linux - both code-based and custom containers, and with App Service on Windows for code-based apps. The integration is in public preview. The integration adds Node.js SDK, which is in GA.

1. Select Application Insights in the Azure control panel for your app service, then select Enable.

   

2. Choose to create a new resource, or select an existing Application Insights resource for this application.

   Note

   When you select OK to create the new resource you will be prompted to Apply monitoring settings. Selecting Continue will link your new Application Insights resource to your app service, doing so will also trigger a restart of your app service.

   

3. Once you've specified which resource to use, you're all set to go.

   

Configuration

The Node.js agent can be configured using JSON. Set the APPLICATIONINSIGHTS_CONFIGURATION_CONTENT environment variable to the JSON string or set the APPLICATIONINSIGHTS_CONFIGURATION_FILE environment variable to the file path containing the JSON.

"samplingPercentage": 80,
"enableAutoCollectExternalLoggers": true,
"enableAutoCollectExceptions": true,
"enableAutoCollectHeartbeat": true,
"enableSendLiveMetrics": true,
...
    

The full set of configurations is available, you just need to use a valid json file.

Enable client-side monitoring

To enable client-side monitoring for your Node.js application, you need to manually add the client-side JavaScript SDK to your application.

Automate monitoring

In order to enable telemetry collection with Application Insights, only the following Application settings need to be set:

Application settings definitions

App setting name	Definition	Value
ApplicationInsightsAgent_EXTENSION_VERSION	Main extension, which controls runtime monitoring.	~2 in Windows or ~3 in Linux.
XDT_MicrosoftApplicationInsights_NodeJS	Flag to control if Node.js agent is included.	0 or 1 (only applicable in Windows).

App Service application settings with Azure Resource Manager

Application settings for Azure App Service can be managed and configured with Azure Resource Manager templates. You can use this method when you deploy new App Service resources with Resource Manager automation or modify the settings of existing resources.

The basic structure of the application settings JSON for an App Service resource:

      "resources": [
        {
          "name": "appsettings",
          "type": "config",
          "apiVersion": "2015-08-01",
          "dependsOn": [
            "[resourceId('Microsoft.Web/sites', variables('webSiteName'))]"
          ],
          "tags": {
            "displayName": "Application Insights Settings"
          },
          "properties": {
            "key1": "value1",
            "key2": "value2"
          }
        }
      ]

For an example of a Resource Manager template with application settings configured for Application Insights, this template can be helpful. Specifically, see the section that starts on line 238.

Automate the creation of an Application Insights resource and link to your newly created App Service resource

To create a Resource Manager template with the default Application Insights settings, begin the process as if you were going to create a new web app with Application Insights enabled.

1. Create a new App Service resource with your desired web app information. Enable Application Insights on the Monitoring tab.

2. Select Review + create. Then select Download a template for automation.

   

   This option generates the latest Resource Manager template with all required settings configured.

   

In the following sample, replace all instances of AppMonitoredSite with your site name:

{
    "resources": [
        {
            "name": "[parameters('name')]",
            "type": "Microsoft.Web/sites",
            "properties": {
                "siteConfig": {
                    "appSettings": [
                        {
                            "name": "APPINSIGHTS_INSTRUMENTATIONKEY",
                            "value": "[reference('microsoft.insights/components/AppMonitoredSite', '2015-05-01').InstrumentationKey]"
                        },
                        {
                            "name": "APPLICATIONINSIGHTS_CONNECTION_STRING",
                            "value": "[reference('microsoft.insights/components/AppMonitoredSite', '2015-05-01').ConnectionString]"
                        },
                        {
                            "name": "ApplicationInsightsAgent_EXTENSION_VERSION",
                            "value": "~2"
                        }
                    ]
                },
                "name": "[parameters('name')]",
                "serverFarmId": "[concat('/subscriptions/', parameters('subscriptionId'),'/resourcegroups/', parameters('serverFarmResourceGroup'), '/providers/Microsoft.Web/serverfarms/', parameters('hostingPlanName'))]",
                "hostingEnvironment": "[parameters('hostingEnvironment')]"
            },
            "dependsOn": [
                "[concat('Microsoft.Web/serverfarms/', parameters('hostingPlanName'))]",
                "microsoft.insights/components/AppMonitoredSite"
            ],
            "apiVersion": "2016-03-01",
            "location": "[parameters('location')]"
        },
        {
            "apiVersion": "2016-09-01",
            "name": "[parameters('hostingPlanName')]",
            "type": "Microsoft.Web/serverfarms",
            "location": "[parameters('location')]",
            "properties": {
                "name": "[parameters('hostingPlanName')]",
                "workerSizeId": "[parameters('workerSize')]",
                "numberOfWorkers": "1",
                "hostingEnvironment": "[parameters('hostingEnvironment')]"
            },
            "sku": {
                "Tier": "[parameters('sku')]",
                "Name": "[parameters('skuCode')]"
            }
        },
        {
            "apiVersion": "2015-05-01",
            "name": "AppMonitoredSite",
            "type": "microsoft.insights/components",
            "location": "China North 2",
            "properties": {
                "ApplicationId": "[parameters('name')]",
                "Request_Source": "IbizaWebAppExtensionCreate"
            }
        }
    ],
    "parameters": {
        "name": {
            "type": "string"
        },
        "hostingPlanName": {
            "type": "string"
        },
        "hostingEnvironment": {
            "type": "string"
        },
        "location": {
            "type": "string"
        },
        "sku": {
            "type": "string"
        },
        "skuCode": {
            "type": "string"
        },
        "workerSize": {
            "type": "string"
        },
        "serverFarmResourceGroup": {
            "type": "string"
        },
        "subscriptionId": {
            "type": "string"
        }
    },
    "$schema": "https://schema.management.azure.com/schemas/2014-04-01-preview/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0"
}

Enable through PowerShell

To enable the application monitoring through PowerShell, only the underlying application settings must be changed. The following sample enables application monitoring for a website called AppMonitoredSite in the resource group AppMonitoredRG. It configures data to be sent to the 012345678-abcd-ef01-2345-6789abcd instrumentation key.

$app = Get-AzWebApp -ResourceGroupName "AppMonitoredRG" -Name "AppMonitoredSite" -ErrorAction Stop
$newAppSettings = @{} # case-insensitive hash map
$app.SiteConfig.AppSettings | %{$newAppSettings[$_.Name] = $_.Value} # preserve non Application Insights application settings.
$newAppSettings["APPINSIGHTS_INSTRUMENTATIONKEY"] = "012345678-abcd-ef01-2345-6789abcd"; # set the Application Insights instrumentation key
$newAppSettings["APPLICATIONINSIGHTS_CONNECTION_STRING"] = "InstrumentationKey=012345678-abcd-ef01-2345-6789abcd"; # set the Application Insights connection string
$newAppSettings["ApplicationInsightsAgent_EXTENSION_VERSION"] = "~2"; # enable the ApplicationInsightsAgent
$app = Set-AzWebApp -AppSettings $newAppSettings -ResourceGroupName $app.ResourceGroup -Name $app.Name -ErrorAction Stop

Troubleshooting

Below is our step-by-step troubleshooting guide for extension/agent based monitoring for Node.js based applications running on Azure App Services.

What's the difference between standard metrics from Application Insights vs. Azure App Service metrics?

Application Insights collects telemetry for the requests that made it to the application. If the failure occurs in WebApps/WebServer, and the request didn't reach the user application, Application Insights doesn't have any telemetry about it.

The duration for serverresponsetime calculated by Application Insights doesn't necessarily match the server response time observed by Web Apps. This behavior is because Application Insights only counts the duration when the request actually reaches the user application. If the request is stuck or queued in WebServer, the waiting time is included in the Web Apps metrics but not in Application Insights metrics.

Test connectivity between your application host and the ingestion service

Application Insights SDKs and agents send telemetry to get ingested as REST calls to our ingestion endpoints. You can test connectivity from your web server or application host machine to the ingestion service endpoints by using raw REST clients from PowerShell or curl commands. See Troubleshoot missing application telemetry in Azure Monitor Application Insights.

Release notes

For the latest updates and bug fixes, consult the release notes.

Next steps

• Monitor Azure Functions with Application Insights.
• Enable Azure diagnostics to be sent to Application Insights.
• Monitor service health metrics to make sure your service is available and responsive.
• Receive alert notifications whenever operational events happen or metrics cross a threshold.
• Use Application Insights for JavaScript apps and web pages to get client telemetry from the browsers that visit a web page.
• Availability overview