Deploying Web Apps with Azure App Services: A Complete Beginner's Guide

📘 Chapter 5: Monitoring, Logging, and Cost Management

🔍 Overview

Managing a web app on Azure goes beyond just deployment. Once your app is live, it's crucial to track its performance, diagnose issues, understand usage trends, and control costs. Azure App Services offers a comprehensive toolset for real-time monitoring, robust logging, and detailed cost management.

In this chapter, we explore how to:

• Enable and analyze logs
• Use Application Insights
• Set up alerts and diagnostics
• Track billing and resource usage
• Optimize app performance and budget

🧠 1. Overview of Monitoring Tools in Azure App Services

Azure offers a suite of tools for observability:

🔧 2. Enabling Diagnostic Logging

Diagnostic logs provide real-time insight into app behavior.

✅ Enable Application Logs

bash

az webapp log config \

  --name mywebapp \

  --resource-group MyResourceGroup \

  --application-logging true \

  --level information

✅ Enable Web Server Logs (Filesystem)

bash

az webapp log config \

  --name mywebapp \

  --resource-group MyResourceGroup \

  --web-server-logging filesystem \

  --retention 7

📁 Log Types

📈 3. Integrating Application Insights

Application Insights offers deep telemetry, real-time alerts, and distributed tracing.

✅ Step 1: Create Application Insights

bash

az monitor app-insights component create \

  --app MyInsights \

  --location eastus \

  --resource-group MyResourceGroup \

  --application-type web

✅ Step 2: Link with App

bash

az webapp config appsettings set \

  --resource-group MyResourceGroup \

  --name mywebapp \

  --settings APPINSIGHTS_INSTRUMENTATIONKEY=<YOUR-KEY>

✅ Common Metrics Tracked

🔍 Query with Kusto (Log Analytics)

kusto

requests

| where timestamp > ago(1h)

| summarize count() by resultCode

🔔 4. Setting Up Alerts

Set alerts when your app exceeds thresholds or fails:

✅ Example: Alert on high CPU

1. Go to Azure Portal → Monitor → Alerts
2. Create a rule
3. Target your App Service
4. Set condition: CPU Usage > 80% for 5 minutes
5. Choose action: Email, Webhook, Azure Function

📋 Alert Use Cases

🔍 5. Log Streaming and Real-Time Debugging

For live log visibility:

bash

az webapp log tail \

  --name mywebapp \

  --resource-group MyResourceGroup

This command streams logs to your terminal in real time.

📊 6. Cost Management and Optimization

✅ View Cost Breakdown

Navigate to:
Azure Portal → Cost Management + Billing → Cost Analysis

Track:

• Per-app cost
• Per-resource group
• Forecasts & anomalies

✅ CLI Cost Breakdown via Cost Management APIs

bash

az consumption usage list \

  --start-date 2024-04-01 \

  --end-date 2024-04-22

📋 Common Cost Triggers in App Services

🧠 Budget Alerts

Set budgets with alert thresholds:

bash

az consumption budget create \

  --amount 50 \

  --name MyAppBudget \

  --resource-group MyResourceGroup \

  --time-grain monthly \

  --time-period start=2024-04-01 end=2024-12-31 \

  --notification-key email \

  --threshold 0.8 \

  --contact-emails user@example.com

🧪 7. Optimization Best Practices

• Enable GZIP Compression
• Turn on Always On for background tasks
• Use deployment slots to separate staging/prod
• Minimize cold starts with appropriate plan tier
• Reduce logs verbosity in production

🧩 Summary Table – Monitoring & Cost Management Tools