AZ-204 Monitor, troubleshoot, and optimize Azure solutions Practice Test 2 — 15 Questions

Question 1

You are developing a .NET application that uses the Azure.Monitor.OpenTelemetry.AspNetCore library to send telemetry to Application Insights. You need to ensure that custom trace spans include the correlation ID from an incoming HTTP header 'X-Correlation-ID' so that you can filter traces by this ID in the Application Insights portal. What should you do?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Add the correlation ID as an attribute to the Activity using 'activity.SetTag("correlationId", correlationId)' and ensure the OpenTelemetry exporter is configured to include it as a custom dimension.. The Azure Monitor OpenTelemetry exporter automatically maps Activity tags (attributes) to Application Insights customDimensions. Therefore, adding the correlation ID as a tag on the Activity ensures it becomes a filterable custom property. Other approaches either rely on the classic SDK or use mechanisms not intended for telemetry enrichment.

Answer

Add the correlation ID as a custom property on the Activity using 'activity.SetTag("correlationId", correlationId)' and configure the Application Insights SDK to map it.

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Implement an ITelemetryInitializer that reads the HTTP header and adds it to the telemetry item's Properties collection.

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Use the 'Activity.Current.AddBaggage("correlationId", correlationId)' method to add the correlation ID as baggage, which is automatically propagated and stored as a custom dimension.

Question 2

You are developing a .NET 6 console application that uses the Azure.Monitor.Query library to query Application Insights logs. You need to authenticate the application to Azure Monitor using the Azure Identity library. The application will run as an Azure AD service principal. You want to follow the principle of least privilege. Which two actions should you perform? (Choose two.)

Accepted Answer

Register the application in Azure AD and create a client secret for authentication.. To authenticate a service principal to Azure Monitor, you must first register an application in Microsoft Entra ID and create a credential (client secret or certificate). Then, you assign the least-privilege role 'Monitoring Reader' at the Application Insights resource scope. This allows the application to query logs while adhering to least privilege. Other roles are either too broad or not scoped correctly.

Answer

Use the 'DefaultAzureCredential' class from Azure.Identity to authenticate the Azure Monitor Query client.

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Assign the 'Contributor' role to the service principal at the subscription scope.

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Assign the 'Log Analytics Reader' role to the service principal at the Log Analytics workspace scope.

Question 3

An e-commerce application emits a high volume of telemetry data to Azure Application Insights. You need to reduce the cost of data ingestion while preserving statistical accuracy for performance metrics. Which sampling technique should you use?

Accepted Answer

Adaptive sampling. Adaptive sampling is the correct choice because it automatically adjusts the sampling rate based on the volume of telemetry data, ensuring that during low-traffic periods all data is retained for statistical accuracy, while during high-traffic periods it reduces the rate to control costs. This technique is specifically designed for high-volume scenarios like e-commerce telemetry, where preserving statistical accuracy for performance metrics (e.g., request durations, failure rates) is critical, and it avoids the manual tuning required by fixed-rate sampling.

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Fixed-rate sampling with a 1% rate

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Ingestion sampling

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Head-based sampling

Question 4

You need to monitor the real-time CPU utilization of an Azure virtual machine. Which Azure Monitor feature is designed for this purpose?

Accepted Answer

Metrics. Azure Monitor Metrics is the correct feature because it collects and stores numeric time-series data from Azure resources, including CPU utilization, at near-real-time intervals (typically every 1 minute for Azure VMs). Metrics are lightweight, low-latency, and designed for real-time monitoring and alerting, making them ideal for tracking CPU usage without the overhead of log ingestion.

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Logs

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Alerts

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Workbooks

Question 5

You have an Azure App Service web app that experiences intermittent slowness. You enable Application Insights and notice that the "Failed Requests" metric is low, but "Server Response Time" is high for a subset of requests. You want to identify the specific code path causing the delay. Which feature should you use?

Accepted Answer

Profiler.. C is correct because the Application Insights Profiler captures detailed call stacks and execution timing for slow requests, allowing you to pinpoint the exact code path causing high server response time. Unlike other features, Profiler is specifically designed for performance troubleshooting by tracing request execution at the code level.

Answer

Live Metrics.

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Snapshot Debugger.

Answer

Availability tests.

Question 6

An Azure Function processes events from Event Hubs. You need to monitor the number of events that were successfully processed and those that were dropped due to processing errors. Which approach should you use?

Accepted Answer

Custom metrics in Application Insights.. Custom metrics in Application Insights allow you to track business-specific counters like successfully processed events and dropped events directly from your Azure Function code. By using the `TelemetryClient.TrackMetric()` API within the function's event processing logic, you can increment counters for success and failure scenarios, giving you precise, real-time monitoring of processing outcomes. This approach is more granular than built-in metrics because it reflects your application's custom error handling, not just infrastructure-level throughput.

Answer

Event Hubs metrics.

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Stream Analytics job.

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Log Analytics query on function logs.

Question 7

Your e-commerce application sends telemetry to Application Insights. You need to reduce ingestion costs while preserving the ability to detect trends in performance metrics. Which sampling type should you configure?

Accepted Answer

Adaptive sampling. Adaptive sampling is the correct choice because it automatically adjusts the volume of telemetry data collected based on the application's activity level, ensuring that performance trends are preserved while reducing ingestion costs. Unlike fixed-rate sampling, adaptive sampling dynamically increases or decreases the sampling rate to maintain a target volume, making it ideal for e-commerce applications with variable traffic patterns.

Answer

Fixed-rate sampling

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Ingestion sampling

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Head-based sampling

Question 8

You need to monitor the CPU utilization of an Azure VM in real-time and set up an alert when it exceeds 90%. Which Azure Monitor feature should you use?

Accepted Answer

Metrics Explorer. Metrics Explorer is the correct Azure Monitor feature for real-time monitoring of CPU utilization on an Azure VM because it provides near real-time metric collection (typically every 1 minute) and supports alerting based on threshold conditions. It allows you to chart performance counters like Percentage CPU and configure metric alerts that trigger when the value exceeds 90%.

Answer

Log Analytics Workspace

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Application Insights

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Azure Monitor for VMs

Question 9

You need to diagnose a slow-performing Azure Function. Application Insights shows that the function's dependency calls to an external API take an unusually long time. Which Application Insights feature should you use to visualize the end-to-end request flow?

Accepted Answer

Application Map. Application Map is the correct feature because it provides a visual representation of the end-to-end request flow across distributed components, including dependency calls to external APIs. It shows the latency and failure rates for each dependency, allowing you to pinpoint where the slowdown occurs in the overall transaction.

Answer

Metrics Explorer

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Live Metrics Stream

Answer

Smart Detection

Question 10

An Azure web app is experiencing high memory usage. You want to collect memory dumps periodically to analyze the issue without restarting the app. Which Azure App Service diagnostic feature should you use?

Accepted Answer

Application Snapshot Debugger. The Application Snapshot Debugger captures memory dumps (snapshots) of a production web app when an exception occurs or when configured to trigger on specific conditions, such as high memory usage, without restarting the app. It is specifically designed for debugging memory leaks and high CPU/memory issues in Azure App Service by providing detailed snapshots of the process state, including the heap, at the point of interest. While not strictly time-based periodic, if the high memory condition occurs repeatedly, the debugger can be configured to capture multiple snapshots over time for analysis.

Answer

Application Insights Profiler

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Diagnostic Settings

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Auto-healing

Question 11

An application uses Azure Application Insights for monitoring. You need to write a query to analyze the number of failed requests and exceptions over the past hour. Which query language should you use?

Accepted Answer

Kusto Query Language (KQL). Azure Application Insights stores telemetry data in a Log Analytics workspace, which is queried using Kusto Query Language (KQL). KQL is the native query language for Azure Data Explorer and is specifically designed for time-series analysis, filtering, and aggregation of log data. To analyze failed requests and exceptions over the past hour, you would use KQL operators like `where`, `summarize`, and `bin` to filter by timestamp and count events.

Answer

SQL

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PowerShell

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Azure CLI

Question 12

Your web app hosted on Azure App Service is experiencing high memory usage. You need to capture a memory dump for analysis without restarting the app. Which diagnostic feature should you use?

Accepted Answer

Azure App Service Diagnostics (Diagnose and solve problems). Azure App Service Diagnostics (Diagnose and solve problems) provides a built-in 'Memory Dump' tool that allows you to capture a full or mini memory dump of your app's process without requiring a restart. This is accessed through the Azure portal under the 'Diagnose and solve problems' blade, specifically via the 'Collect Memory Dump' diagnostic tool, which uses the Windows Debugging Tools to snapshot the w3wp.exe process while the app continues running.

Answer

Application Insights Profiler

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Snapshot Debugger

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Diagnostic settings

Question 13

You need to monitor the performance of an Azure web app. You want to track the average response time and the number of failed requests over the last hour. Which Azure service should you use?

Accepted Answer

Application Insights. Application Insights is the correct choice because it is an extensible Application Performance Management (APM) service designed specifically for monitoring live web applications. It can track metrics like average response time and failed request counts out of the box, and it integrates directly with Azure Web Apps via the Application Insights SDK or auto-instrumentation, providing real-time telemetry without requiring custom logging code.

Answer

Azure Monitor

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Log Analytics

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Azure Advisor

Question 14

You are troubleshooting an Azure Function that intermittently throws exceptions. You have enabled Application Insights. You need to capture the exact line of code that caused the exception, even for exceptions that occur during high load. Which feature should you use?

Accepted Answer

Snapshot Debugger. Snapshot Debugger is the correct choice because it captures a point-in-time snapshot of the call stack and local variables at the exact line where an exception occurs, even under high load. This allows you to see the precise line of code and state that caused the failure, which is essential for diagnosing intermittent exceptions. Application Insights integrates Snapshot Debugger to automatically collect these snapshots for thrown exceptions without requiring manual instrumentation.

Answer

Application Insights Profiler

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Live Metrics Stream

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SQL Insights

Question 15

You are monitoring an Azure Web App with Application Insights. You notice that certain requests have high server response times. You need to identify which specific database queries are causing the delays. Which Application Insights feature should you use?

Accepted Answer

Application Insights Profiler. Application Insights Profiler is the correct feature because it provides detailed, code-level diagnostics for requests with high server response times, including per-operation breakdowns of database query durations. It captures execution traces that show exactly which SQL queries or external calls are contributing to latency, enabling you to pinpoint the specific database queries causing delays.

Answer

Live Metrics Stream

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Performance blade

Answer

Application Map