Enable Application Logging and Diagnostics for Azure App Service

Azure App Service generates multiple categories of diagnostic data - HTTP request logs, application-level output, console messages, and platform events - but none of these are captured or retained by default. Without deliberate configuration, errors vanish after they scroll past the console buffer, and performance issues go undetected until users complain.

In this lab, you will enable application logging on a pre-provisioned App Service web app, configure diagnostic settings to send logs to a Log Analytics workspace, observe log output in real-time using the Log Stream feature, and write KQL queries against the AppServiceHTTPLogs table to identify 5xx errors and slow requests.

Objectives

Upon completing this intermediate level lab, you will be able to:

• Enable application logging (filesystem) on an Azure App Service web app
• Configure diagnostic settings to route HTTP logs, console logs, and application logs to a Log Analytics workspace
• Stream application logs in real-time using the Azure portal Log Stream feature
• Write KQL queries against the AppServiceHTTPLogs table to identify and analyze 5xx server errors
• Query Log Analytics to find slow requests using response time percentile analysis
• Correlate HTTP logs with console logs to troubleshoot application issues

Who is this lab for?

This lab is designed for:

• Cloud engineers preparing for the AZ-104 or AZ-204 certification who need hands-on experience with App Service monitoring
• Administrators learning to configure diagnostic logging and troubleshoot web application issues