AZ-204 Developing Solutions for Microsoft Azure Exam

Implement and Utilize Application Insights

Application Insights is Azure Monitor’s application performance monitoring service that helps you monitor and troubleshoot Azure solutions. It gathers telemetry data—including metrics, logs, and traces—from your applications. You can enable monitoring quickly with autoinstrumentation or get deeper insights by using the OpenTelemetry SDK for manual setup. Autoinstrumentation requires no code changes, while manual instrumentation gives you full control over what data you collect. If both methods are used, only the manual settings run to prevent duplicate data.

After you instrument your app, Application Insights automatically captures key telemetry items to help you understand usage and issues. These items include:

• Requests and dependencies to show how your app talks to clients and other services
• Exceptions and traces for detailed error and debug details
• Custom events and metrics for business or application-specific data

These signals give you a clear view of how your app performs and where it might be failing.

Application Insights supports three main metric types, each serving different needs.

• Standard metrics are preaggregated and ideal for fast, real-time alerting.
• Log-based metrics come from custom queries and enable in-depth analysis with all log properties.
• Custom metrics let you define what you want to measure directly in the SDK.

Keep in mind that sampling and filtering can affect the accuracy of log-based metrics, so choose settings that match your diagnostic goals.

To explore and act on your telemetry, use these built-in Azure portal experiences:

• Application Map shows a visual diagram of your app components and their interactions
• Live Metrics provides near-real-time charts for CPU, request rates, and dependencies
• Transaction Search and Logs (Analytics) let you filter and query data using Kusto Query Language (KQL)

You can then build custom visuals and alerts:

• Metrics Explorer and Workbooks for interactive dashboards
• Alerts with static or dynamic thresholds to notify you of issues automatically
• Log queries that group events by identifiers like operation_Id or InvocationId

These tools help you detect, diagnose, and resolve performance and reliability issues quickly.

Conclusion

In this section, you learned how to set up Application Insights to collect metrics, logs, and traces from your Azure applications. You saw the difference between autoinstrumentation and manual SDK configuration, and why it’s important to avoid duplicate data. You explored the three metric types—standard, log-based, and custom—and how sampling and filtering affect them. Finally, you discovered how to use portal tools like Application Map, Live Metrics, and Workbooks, alongside alerts and log queries, to get a complete view of your app’s health and performance.