This video provides a quick walkthrough Log Alerts for Application Insights. Application Insights is an extensible Application Performance Management (APM) service for web developers on multiple platforms. Customers use Application Insights to monitor live web applications, detect performance anomalies, diagnose issues and to understand usage patterns.
This video shows how you can now monitor even log files by setting up a to run at specified intervals and trigger alerts based on the result. For example, let's say you deployed a new fix for a specific exception and want to make sure it doesn't surface again. You can now setup an alert to trigger if that exception appears in your Application Insights trace file. You can learn more about log alerts in Microsoft Azure Documentation for Log Alerts.