AZ-204 Monitor, troubleshoot, and optimize Azure solutions Practice Test 3 — 15 Questions

Question 1

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. 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.

Answer

The Application Insights SDK is not installed in the application

Answer

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

Answer

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

Question 2

You are monitoring an Azure Web App with Application Insights. You notice a sudden spike in failed requests. You need to quickly identify which specific URL path is causing the most failures. Which blade in the Application Insights portal should you use?

Accepted Answer

Failures blade. The Failures blade in Application Insights is specifically designed to analyze failed requests, including HTTP 4xx and 5xx errors, and provides a breakdown by URL path, response code, and failure count. This allows you to quickly identify the specific URL path causing the most failures, which directly addresses the need to pinpoint the problematic endpoint.

Answer

Application Map

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Performance blade

Answer

Live Metrics Stream

Question 3

You are monitoring an Azure Web App with Application Insights. You notice that the dependency duration for a SQL database call has significantly increased. You need to identify the specific SQL query that is causing the slowness. Which Application Insights feature should you use?

Accepted Answer

Performance blade and drill into Dependencies. The Performance blade in Application Insights allows you to drill into specific operations, including dependencies. By selecting the SQL dependency with increased duration, you can view the 'Dependencies' tab to see the exact SQL query text, duration, and other details. This directly identifies the slow query without needing to instrument code changes.

Answer

Application Map

Answer

Live Metrics Stream

Answer

Smart Detection

Question 4

You are running an Azure App Service web app on the Basic tier. Users report slow initial responses due to cold starts. You need to keep the app warm without upgrading the hosting plan. Which feature should you enable?

Accepted Answer

Enable 'Always On' in the App Service configuration.. The 'Always On' feature prevents the App Service from being unloaded after periods of inactivity, eliminating cold starts by keeping the application loaded in memory. This is available on the Basic tier and above, so it solves the problem without requiring a plan upgrade.

Answer

Upgrade to a Premium plan to get pre-warmed instances.

Answer

Implement an auto-scaling rule to maintain a minimum instance count.

Answer

Reduce the web app's idle timeout via application code.

Question 5

You are monitoring an Azure App Service with Application Insights. You need to create a custom dashboard that shows the number of requests over time and the average server response time. Which Application Insights feature should you use to create this dashboard?

Accepted Answer

Metrics Explorer. Metrics Explorer is the correct feature because it allows you to create custom charts and dashboards by selecting specific metrics like 'Requests' and 'Server response time' from your Application Insights resource. You can aggregate these metrics over time and pin them to an Azure dashboard for monitoring. Live Metrics Stream shows real-time data but cannot be used for historical charting or dashboard pinning, while Analytics (Logs) requires Kusto queries for custom visualizations and is not optimized for simple metric dashboards.

Answer

Live Metrics Stream

Answer

Analytics (Logs)

Answer

Availability Tests

Question 6

You are monitoring an ASP.NET Core web API with Application Insights. You want to view the SQL queries being executed, including the command text and duration, in the Application Insights portal. Which actions must you take? (Select all that apply.) (Choose 2.)

Accepted Answer

Install the `Microsoft.ApplicationInsights.DependencyCollector` NuGet package.. The `Microsoft.ApplicationInsights.DependencyCollector` NuGet package is required to automatically collect dependency telemetry, including SQL Server calls. Without this package, Application Insights will not capture SQL dependency data at all. Option C is correct because even with the dependency collector installed, SQL command text is not collected by default for security reasons; you must explicitly set `EnableSqlCommandTextInstrumentation` to `true` in the `DependencyTrackingTelemetryModule` configuration to view the actual SQL queries and their duration in the portal.

Answer

Install the `Microsoft.ApplicationInsights.Profiler.AspNetCore` NuGet package.

Answer

Enable adaptive sampling to ensure all SQL queries are collected.

Question 7

You are using Application Insights to monitor a web application. You need to create an alert that triggers when the server response time exceeds 5 seconds for more than 10% of requests in a 5-minute window. Which type of Azure Monitor alert should you create?

Accepted Answer

Log alert. A log alert is correct because the condition involves querying Application Insights trace data to calculate the percentage of requests with a server response time exceeding 5 seconds within a 5-minute window. Log alerts run a Kusto query against the `requests` table, allowing aggregation and threshold evaluation (e.g., >10% of requests), which is not possible with simple metric thresholds.

Answer

Metric alert

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Activity log alert

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Application Insights smart detection alert

Question 8

You are monitoring an Azure web application with Application Insights. You notice a sudden increase in the number of failed requests. You want to be notified automatically when such anomalies occur, without manually setting static thresholds. Which Application Insights feature should you use?

Accepted Answer

Enable Smart Detection for failure anomalies.. Smart Detection for failure anomalies in Application Insights uses machine learning to automatically detect unusual patterns in failed request rates without requiring manual threshold configuration. This feature is specifically designed to notify you of anomalies based on historical behavior, making it the correct choice for the scenario described.

Answer

Create a metric alert on the 'failed requests' metric with a static threshold.

Answer

Use Log Analytics to run a query every 5 minutes and trigger an action.

Answer

Create an availability test that periodically pings the application.

Question 9

You are using Application Insights to monitor an ASP.NET Core web API. Users report that a specific endpoint is slow, but you cannot reproduce the issue in development. You need to identify which line of code is causing the delay in production. Which Application Insights feature should you use?

Accepted Answer

Enable Application Insights Profiler.. Application Insights Profiler is designed specifically to trace code-level performance issues in production without requiring code changes or reproducing the problem. It captures detailed call stacks and timing for each request, allowing you to identify exactly which line of code is causing the delay. This makes it the correct choice for diagnosing a slow endpoint that cannot be reproduced in development.

Answer

Use the Application Insights Map to visualize dependencies.

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Use the Snapshot Debugger to capture debug snapshots on exceptions.

Answer

Create a custom telemetry event in the slow endpoint to log timing data.

Question 10

You are monitoring an Azure web application with Application Insights. You want to create a custom dashboard that shows the number of requests over time and the average server response time. Which Application Insights feature should you use to create this dashboard?

Accepted Answer

Metrics Explorer. Metrics Explorer in Application Insights is designed for visualizing pre-aggregated metrics like request count and server response time over time. It allows you to create custom charts and pin them to an Azure dashboard, making it the correct choice for this monitoring requirement.

Answer

Log Analytics

Answer

Application Map

Answer

Smart Detection

Question 11

You are using Application Insights to monitor a web application. The business team wants to track how many users click a specific button on the page. You need to send custom telemetry data from the client-side JavaScript. Which Application Insights JavaScript SDK method should you call?

Accepted Answer

appInsights.trackEvent. The correct method is `trackEvent` because it is specifically designed for capturing user interactions, such as button clicks, as custom events in Application Insights. Unlike other methods, `trackEvent` allows you to attach custom properties and measurements, making it ideal for business metrics like click tracking. This method sends the data as a custom event telemetry item, which can be analyzed in the Azure portal under 'Events'.

Answer

appInsights.trackTrace

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appInsights.trackPageView

Answer

appInsights.trackException

Question 12

You are monitoring an e-commerce application with Application Insights. You need to analyze all exceptions that occurred in the last 24 hours, grouped by the exception type. You also need to include the URL where each exception was triggered and the number of times each type occurred. Which Log Analytics Kusto query should you use?

Accepted Answer

exceptions | where timestamp > ago(24h) | join kind=inner requests on operation_Id | extend exceptionType = tostring(innermostType) | summarize Count=count() by exceptionType, url. It uses the `exceptions` table to filter exceptions from the last 24 hours, joins with the `requests` table on `operation_Id` to correlate each exception with the request URL, and then summarizes the count by exception type (extracted from `innermostType`) and URL. This meets all requirements: grouping by exception type, including the URL, and counting occurrences.

Answer

exceptions | where timestamp > ago(24h) | extend exceptionType = tostring(customDimensions.['ExceptionType']) | summarize Count=count() by exceptionType, url = tostring(customDimensions.['Url'])

Answer

requests | where timestamp > ago(24h) and success == false | extend exceptionType = tostring(resultCode) | summarize Count=count() by exceptionType, url

Answer

exceptions | where timestamp > ago(24h) | extend exceptionType = tostring(innermostType) | summarize Count=count() by exceptionType

Question 13

You manage a web application hosted on Azure App Service. You need to monitor the application's availability from multiple geographic locations. The test should check that the homepage loads successfully and returns HTTP 200 within 5 seconds. You want to receive an alert if the test fails from any location. Which type of Application Insights test should you create?

Accepted Answer

URL ping test. The URL ping test is the correct choice because it is a simple, single-URL availability test that checks whether a specific endpoint (the homepage) returns HTTP 200 within a specified timeout (5 seconds). It can be configured to run from multiple geographic locations and trigger an alert on failure, meeting all requirements without the complexity of multi-step or custom code.

Answer

Multi-step web test

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Custom availability test using TrackAvailability

Answer

Continuous export test

Question 14

You are debugging a performance issue in a live web application monitored by Application Insights. You need to see real-time metrics such as request rate, response times, and any exceptions as they occur, without waiting for the usual telemetry pipeline. Which Application Insights feature should you use?

Accepted Answer

Live Metrics Stream. Live Metrics Stream (option B) is the correct feature because it provides real-time, low-latency telemetry directly from the Application Insights SDK, bypassing the usual ingestion pipeline. This allows you to monitor request rate, response times, and exceptions as they occur, which is exactly what the scenario requires for debugging a live performance issue without waiting for data to be processed.

Answer

Application Insights Analytics (Log Analytics)

Answer

Metrics Explorer

Answer

Application Insights Profiler

Question 15

You need to analyze all exceptions that occurred in the last 24 hours from an application monitored by Application Insights. You want to group them by exception type, and for each type show the URL where it occurred and the count. Which Log Analytics Kusto query should you use?

Accepted Answer

exceptions | where timestamp > ago(24h) | summarize count() by type, url. The query filters exceptions from the last 24 hours using `timestamp > ago(24h)`, groups them by `type` (exception type) and `url` (the URL where the exception occurred), and then counts occurrences per group with `summarize count()`. This directly matches the requirement to show, for each exception type, the URL and the count.

Answer

exceptions | where timestamp > ago(24h) | summarize count() by type, cloud_RoleInstance

Answer

exceptions | where timestamp > ago(24h) | summarize count() by type, operation_Name

Answer

exceptions | where timestamp > ago(24h) | summarize count() by type