Skip to main content

📊 Azure Application Insights & Azure Monitor (Interview Guide)


🟢 Azure Monitor

✅ What is it?

  • A unified monitoring service in Azure for metrics, logs, and alerts.
  • Collects data from apps, VMs, containers, databases, storage, networking, etc.
  • Acts as the foundation for observability in Azure.

👉 Think of Azure Monitor as the big umbrella → it collects & stores monitoring data.

✅ Key Components

  • Metrics → numerical time-series data (CPU %, memory, requests/sec).
  • Logs → detailed event & diagnostic data (stored in Log Analytics).
  • Alerts → notifications when thresholds are crossed.
  • Dashboards → visualize metrics/logs.
  • Workbooks → custom interactive reports.

🟢 Azure Application Insights (App Insights)

✅ What is it?

  • An APM (Application Performance Monitoring) service under Azure Monitor.
  • Monitors application performance, failures, requests, dependencies, and usage.
  • Works with .NET, Java, Node.js, Python, and front-end JS apps.

👉 Think of App Insights as the “inside view” of your app, while Azure Monitor is the “outside view” of the entire infrastructure.

✅ Key Features

  • Request tracking → HTTP/API calls, response times.
  • Dependency tracking → DB calls, external services, APIs.
  • Exception logging → auto-capture unhandled errors.
  • Distributed Tracing → track requests across microservices.
  • Live Metrics Stream → see real-time requests & failures.
  • Smart Detection → automatic anomaly alerts.

🟢 How They Work Together

  • Azure Monitor → collects logs & metrics from all Azure resources.
  • Application Insights → specializes in application-level monitoring.
  • App Insights sends data to Azure Monitor Logs (Log Analytics workspace).

🟢 Example: Enable App Insights in .NET

// Program.cs in .NET 6/7+
var builder = WebApplication.CreateBuilder(args);

// Add Application Insights telemetry
builder.Services.AddApplicationInsightsTelemetry();

var app = builder.Build();

app.MapGet("/", () => "Hello Azure Monitor!");
app.Run();

👉 This automatically tracks requests, dependencies, and exceptions.

🟢 Security & Best Practices

  • Don’t log sensitive data (PII, secrets).
  • Use Sampling → reduce telemetry cost by only sending a % of requests.
  • Use Custom Events/Properties for business metrics.
  • Enable Alerts → e.g., notify when request failure > 5%.

🟢 Common Interview Questions

Azure Monitor

  1. What is Azure Monitor?
  2. Difference between Metrics and Logs?
  3. How do you set up alerts?
  4. What is Log Analytics?

Application Insights

  1. What does App Insights monitor?
  2. Difference between App Insights and Log Analytics?
  3. How do you enable App Insights in .NET?
  4. What is Distributed Tracing?
  5. What is Sampling in App Insights?
  6. How do you track custom events in App Insights?

🟢 Pros & Cons

Application Insights

✅ Easy integration with apps.
✅ Powerful APM features (tracing, requests, failures).
✅ Live metrics & smart detection.
❌ Cost grows with high telemetry.
❌ Overhead if not sampled properly.

Azure Monitor

✅ Single pane for infra + app monitoring.
✅ Flexible queries (KQL in Log Analytics).
✅ Alerts, dashboards, automation.
❌ Querying requires KQL learning curve.

✅ Quick Recap

  • Azure Monitor = big umbrella (infra + app monitoring).
  • App Insights = application-level monitoring (APM).
  • Monitor → Metrics, Logs, Alerts.
  • App Insights → Requests, Dependencies, Exceptions, Tracing.
  • Always mention → integration, sampling, alerts, dashboards in interviews.


Comments

Post a Comment