AZ-204 Monitor, troubleshoot, and optimize Azure solutions — Timed 40 Questions

Question 1

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 2

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 3

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.

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Live Metrics.

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Snapshot Debugger.

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Availability tests.

Question 4

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.

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Event Hubs metrics.

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Stream Analytics job.

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Log Analytics query on function logs.

Question 5

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.

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Fixed-rate sampling

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Ingestion sampling

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Head-based sampling

Question 6

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%.

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Log Analytics Workspace

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Application Insights

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Azure Monitor for VMs

Question 7

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.

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Metrics Explorer

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Live Metrics Stream

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Smart Detection

Question 8

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 is the correct feature because it captures memory dumps (snapshots) of a production web app at the point of an exception or high memory usage without restarting the app. It is specifically designed for debugging memory leaks and high CPU/memory issues in Azure App Service, providing a periodic snapshot of the process heap.

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Application Insights Profiler

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Diagnostic Settings

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Auto-healing

Question 9

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.

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SQL

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PowerShell

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Azure CLI

Question 10

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.

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Application Insights Profiler

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Snapshot Debugger

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Diagnostic settings

Question 11

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.

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Azure Monitor

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Log Analytics

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Azure Advisor

Question 12

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.

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Application Insights Profiler

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Live Metrics Stream

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SQL Insights

Question 13

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.

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Live Metrics Stream

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Performance blade

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Application Map

Question 14

Your Azure web app is running in a production environment. Users report that the app is slow. You need to identify the root cause without impacting production traffic. Which approach should you use?

Accepted Answer

Enable Application Insights Profiler. Application Insights Profiler provides detailed, per-request performance traces that pinpoint which code paths are consuming the most time, enabling root cause analysis of slow responses without altering production traffic. Unlike sampling or logs, Profiler captures execution data on-demand or automatically with minimal overhead, making it ideal for diagnosing latency issues in a live environment.

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Enable Application Insights sampling at 100%

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Run a load test in a staging slot

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Review server logs in the web app

Question 15

You are using Application Insights to monitor a web app. You want to automatically analyze and alert on sudden increases in request failure rates, without manually setting static thresholds. Which Application Insights feature should you use?

Accepted Answer

Smart Detection. Smart Detection in Application Insights automatically analyzes telemetry from your web app to detect anomalies, such as sudden increases in request failure rates, without requiring manual static thresholds. It uses machine learning models to adapt to your app's normal behavior and alert on deviations, making it ideal for dynamic monitoring scenarios.

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Application Insights Profiler

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Live Metrics Stream

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Continuous Export

Question 16

You are monitoring an Azure App Service using Application Insights. You notice that HTTP 500 errors are increasing, but the standard server response time metric remains normal. You suspect that the errors are occurring in an external API call made by the application. How can you identify the dependency that is failing?

Accepted Answer

Configure Application Insights dependency tracking and view the Dependency Metrics blade.. Option C is correct because Application Insights dependency tracking automatically monitors HTTP calls, SQL queries, and other external dependencies made by your application. By viewing the Dependency Metrics blade, you can see failure rates, durations, and dependency names, allowing you to identify which external API call is failing without modifying code.

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Enable snapshot debugging for the application.

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Use Application Insights Profiler to capture code-level traces.

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Set up a custom event telemetry for each external call.

Question 17

You are monitoring an Azure Function app that processes messages from an Event Hub. You want to be alerted if the function is failing to process messages (e.g., exceptions) and automatically restart the function host. Which Azure service should you use?

Accepted Answer

Azure Monitor alerts with a metric alert on exception count.. Azure Monitor metric alerts on exception count can trigger when the function app throws exceptions during message processing. By configuring an alert rule that fires on the 'Exceptions' metric, you can then set up an action group that includes an auto-remediation step, such as restarting the function app host via a webhook or Azure Automation runbook. This directly addresses the requirement to be alerted and automatically restart the host.

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Application Insights availability tests.

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Azure Service Health alerts.

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Azure Advisor recommendations.

Question 18

You are monitoring an Azure App Service using Application Insights. You notice that the server response time is high for certain requests. You need to drill down to see which external dependencies (like databases or APIs) are causing the delay. Which Application Insights feature should you use?

Accepted Answer

Profiler. Profiler (C) is correct because it provides a detailed, code-level view of request processing, including the time spent on each external dependency call (e.g., SQL queries, HTTP calls to APIs). It captures execution traces that break down the total server response time into individual dependency durations, allowing you to pinpoint which external service is causing the delay.

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Live Metrics

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Application Map

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Snapshot Debugger

Question 19

You are monitoring an Azure Web App using Application Insights. You need to track the duration and status code of an external API call made by the app. Which Application Insights feature should you use?

Accepted Answer

Dependency tracking feature. Dependency tracking in Application Insights is specifically designed to monitor calls made by your application to external services, such as APIs, databases, or HTTP endpoints. It automatically captures the duration, success/failure status, and response code of outbound HTTP requests, making it the correct choice for tracking an external API call's duration and status code.

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Built-in request telemetry (server-side requests)

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Custom events (TrackEvent)

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Page view tracking

Question 20

You have enabled Application Insights on your Azure Web App. You notice that some server-side exceptions are not appearing in the Application Insights portal. What is the most likely reason?

Accepted Answer

The exceptions are being caught and handled in code without being re-thrown or explicitly logged. Option D is correct because Application Insights only captures exceptions that are unhandled or explicitly logged via the SDK. If an exception is caught in a try-catch block and not re-thrown or logged using `TelemetryClient.TrackException()`, it will not appear in the portal. This is a common oversight when developers handle exceptions silently without instrumentation.

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The Application Insights SDK is not installed in the application

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The developer forgot to set the Instrumentation Key in the application configuration

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The web app is running on a Free tier App Service plan