Microsoft Certified: Azure Fundamentals (AZ-900) Practice Exam

To determine how many times your web app has been unavailable during the past month, utilizing the health history feature is the most suitable approach. This feature provides historical data regarding the availability of the web app, including any outages or availability issues experienced over a specific period. By examining this data, you can analyze patterns of availability and gain insights into the operational reliability of your application.

Health advisories, on the other hand, typically inform users about potential issues or expected maintenance that could affect service performance in the future, rather than providing a retrospective view of outages. Health alerts serve to notify users in real-time of issues as they occur but do not provide a comprehensive historical overview. Service issues may report ongoing or recently resolved incidents affecting services but do not consolidate this information into a historical format that spans a specified time frame, such as a month. Thus, health history is the appropriate feature for analyzing past availability data.