An alert is a feature which enables you to be notified when an anomaly occurs. There are plenty of different possibilities when it comes to setting up an alert, starting with an ARM template:
{ "name": "[variables('myFirstAlertName')]", "type": "Microsoft.Insights/alertrules", "apiVersion": "2014-04-01", "location": "[parameters('appLocation')]", "dependsOn": [ "[resourceId('Microsoft.Insights/components', parameters('myApplicationName'))]" ], "tags": { "[concat('hidden-link:', resourceId('Microsoft.Insights/components', parameters('myApplicationName')))]": "Resource" }, "properties": { "name": "[variables('responseAlertName')]", "description": "response time alert", "isEnabled": true, "condition": { "$type": "Microsoft.WindowsAzure.Management.Monitoring.Alerts.Models.ThresholdRuleCondition, ...