Application Insights for apps in Azure - Mini Project: Build & Apply

Application Insights for apps

📖 Scenario: You are working on a cloud application hosted in Azure. You want to monitor its performance and usage by setting up Application Insights. This will help you see how your app is doing and find any problems quickly.

🎯 Goal: Set up Application Insights for an Azure web app by creating the resource, configuring the instrumentation key, and enabling monitoring.

📋 What You'll Learn

Create an Application Insights resource with the exact name MyAppInsights

Create a variable called instrumentation_key to hold the instrumentation key from the resource

Configure the Azure web app to use the instrumentation_key

Enable Application Insights monitoring on the Azure web app

💡 Why This Matters

🌍 Real World

Application Insights helps developers and operators monitor live applications to detect issues and understand usage patterns.

💼 Career

Knowing how to set up and configure Application Insights is a key skill for cloud engineers and developers working with Azure apps.

1

Create Application Insights resource

Create an Application Insights resource in Azure with the exact name MyAppInsights using Azure CLI command az monitor app-insights component create.

Azure

# Your code here to create Application Insights resource named MyAppInsights

Hint

Use az monitor app-insights component create with --app MyAppInsights to create the resource.

2

Get instrumentation key

Create a variable called instrumentation_key and assign it the instrumentation key value from the Application Insights resource MyAppInsights using Azure CLI.

Azure

az monitor app-insights component create --app MyAppInsights --location eastus --resource-group MyResourceGroup --application-type web
# Your code here to get instrumentation key and assign to variable instrumentation_key

Hint

Use az monitor app-insights component show with --query instrumentationKey to get the key.

3

Configure web app with instrumentation key

Use Azure CLI to set the application setting APPINSIGHTS_INSTRUMENTATIONKEY on the Azure web app named MyWebApp in resource group MyResourceGroup to the value of the variable instrumentation_key.

Azure

az monitor app-insights component create --app MyAppInsights --location eastus --resource-group MyResourceGroup --application-type web
instrumentation_key=$(az monitor app-insights component show --app MyAppInsights --resource-group MyResourceGroup --query instrumentationKey -o tsv)
# Your code here to set APPINSIGHTS_INSTRUMENTATIONKEY on MyWebApp

Hint

Use az webapp config appsettings set to add the instrumentation key setting.

4

Enable Application Insights monitoring

Enable Application Insights monitoring on the Azure web app MyWebApp in resource group MyResourceGroup by linking it to the Application Insights resource MyAppInsights using Azure CLI.

Azure

az monitor app-insights component create --app MyAppInsights --location eastus --resource-group MyResourceGroup --application-type web
instrumentation_key=$(az monitor app-insights component show --app MyAppInsights --resource-group MyResourceGroup --query instrumentationKey -o tsv)
az webapp config appsettings set --name MyWebApp --resource-group MyResourceGroup --settings APPINSIGHTS_INSTRUMENTATIONKEY=$instrumentation_key
# Your code here to enable Application Insights monitoring on MyWebApp

Hint

Use az webapp update to finalize enabling monitoring if needed.

Practice

1. What is the main purpose of Azure Application Insights?

easy

A. To monitor the health and usage of applications

B. To create virtual machines in Azure

C. To store large amounts of data

D. To manage user identities and access

Solution

1. Step 1: Understand Application Insights role

   Application Insights is designed to monitor apps by collecting data about their performance and usage.

2. Step 2: Compare with other Azure services

   Other options like virtual machines, data storage, or identity management are handled by different Azure services.

3. Final Answer:

   To monitor the health and usage of applications -> Option A

4. Quick Check:

   Monitoring apps = To monitor the health and usage of applications [OK]

Hint: Think monitoring and diagnostics for apps [OK]

Common Mistakes:

• Confusing Application Insights with storage services
• Mixing it up with Azure Active Directory
• Assuming it creates or manages infrastructure

2. Which of the following is the correct way to enable Application Insights in an Azure Web App?

easy

A. Create a virtual machine and install Application Insights manually

B. Add Application Insights SDK and configure instrumentation key

C. Enable Azure Monitor logs only

D. Use Azure Blob Storage to store telemetry data

Solution

1. Step 1: Identify how to enable Application Insights

   Enabling Application Insights requires adding its SDK to the app and setting the instrumentation key for telemetry.

2. Step 2: Eliminate incorrect options

   Creating VMs or using Blob Storage does not enable Application Insights. Azure Monitor logs are related but separate.

3. Final Answer:

   Add Application Insights SDK and configure instrumentation key -> Option B

4. Quick Check:

   SDK + instrumentation key = Add Application Insights SDK and configure instrumentation key [OK]

Hint: SDK plus key enables monitoring [OK]

Common Mistakes:

• Thinking Application Insights runs on VMs only
• Confusing Azure Monitor logs with Application Insights
• Using storage services for telemetry data

3. Given this snippet in an Azure Function app:

var telemetryClient = new TelemetryClient();
telemetryClient.TrackEvent("OrderPlaced");

What will Application Insights record?

medium

A. An error log with message 'OrderPlaced'

B. A performance metric for function execution time

C. An event named 'OrderPlaced' in the telemetry data

D. No data because TelemetryClient is not initialized

Solution

1. Step 1: Understand TrackEvent method

   TrackEvent sends a custom event named as the string argument to Application Insights.

2. Step 2: Check the code behavior

   The code creates a TelemetryClient and tracks an event called 'OrderPlaced', so this event will be recorded.

3. Final Answer:

   An event named 'OrderPlaced' in the telemetry data -> Option C

4. Quick Check:

   TrackEvent sends event = An event named 'OrderPlaced' in the telemetry data [OK]

Hint: TrackEvent logs custom events [OK]

Common Mistakes:

• Assuming TrackEvent logs errors
• Thinking it measures performance automatically
• Believing TelemetryClient needs extra setup to send events

4. You added Application Insights to your app but see no telemetry data in the Azure portal. What is the most likely cause?

medium

A. Application Insights service is not available in your region

B. Azure subscription is expired

C. You need to restart the Azure portal

D. Instrumentation key is missing or incorrect in app configuration

Solution

1. Step 1: Check telemetry data flow requirements

   Telemetry requires the correct instrumentation key configured in the app to send data to Application Insights.

2. Step 2: Evaluate other options

   Subscription expiry or service region issues would cause broader failures, and restarting the portal does not affect telemetry data.

3. Final Answer:

   Instrumentation key is missing or incorrect in app configuration -> Option D

4. Quick Check:

   Missing key blocks telemetry = Instrumentation key is missing or incorrect in app configuration [OK]

Hint: Check instrumentation key first [OK]

Common Mistakes:

• Restarting portal expecting data to appear
• Assuming regional availability blocks telemetry silently
• Ignoring app configuration settings

5. You want to monitor a multi-service app with Application Insights and correlate requests across services. What should you do?

hard

A. Enable distributed tracing and use the same Application Insights resource for all services

B. Create separate Application Insights resources for each service without linking

C. Use Azure Monitor logs only without Application Insights

D. Send telemetry data manually to a storage account

Solution

1. Step 1: Understand distributed tracing in Application Insights

   Distributed tracing allows tracking requests across multiple services by sharing context and using the same Application Insights resource.

2. Step 2: Compare options for multi-service monitoring

   Using separate resources without linking breaks correlation. Azure Monitor logs alone do not provide this tracing. Manual telemetry to storage lacks correlation features.

3. Final Answer:

   Enable distributed tracing and use the same Application Insights resource for all services -> Option A

4. Quick Check:

   Distributed tracing + shared resource = Enable distributed tracing and use the same Application Insights resource for all services [OK]

Hint: Use distributed tracing with shared resource [OK]

Common Mistakes:

• Splitting telemetry into unlinked resources
• Ignoring distributed tracing setup
• Relying only on logs without correlation