Monitoring App Services

Effective monitoring is crucial for understanding the health, performance, and resource utilization of your application services. This guide outlines the key tools and metrics available for monitoring your app services, helping you to proactively identify and resolve issues.

Key Monitoring Areas

When monitoring app services, focus on these core areas:

• Performance Metrics: Track response times, request rates, error rates, and CPU/memory usage.
• Availability: Ensure your service is accessible and responding to requests.
• Resource Utilization: Monitor disk space, network traffic, and database connections.
• Application Logs: Capture detailed information about application events, warnings, and errors.
• Security Events: Monitor for suspicious activity and potential security breaches.

Tools and Features

Azure Application Insights

Azure Application Insights is a powerful Application Performance Management (APM) service that is integrated with Azure App Service. It provides rich telemetry about your application's performance and usage.

Key features of Application Insights include:

• Live Metrics Stream: Real-time monitoring of application requests, performance, and failures.
• Performance Analysis: Identify performance bottlenecks and slow-running operations.
• Failure Analysis: Detect, diagnose, and prioritize exceptions and failures.
• Usage Analysis: Understand how users interact with your application.
• Alerting: Configure alerts based on predefined metrics or custom queries.

Azure Monitor

Azure Monitor is a comprehensive solution for collecting, analyzing, and acting on telemetry from your Azure and on-premises environments. It provides a unified view of application health and performance.

Key components of Azure Monitor for App Services:

• Metrics: Collects numerical data about your app service, such as CPU percentage, memory working set, HTTP server errors, and data in/out.
• Logs: Collects log data from your app service, including application logs, web server logs, and diagnostics logs.
• Alerts: Allows you to set up rules to trigger notifications or actions when specific conditions are met.
• Dashboards: Create custom dashboards to visualize key metrics and logs in one place.

Configuring Monitoring

Enabling Application Insights

To enable Application Insights for your App Service:

1. Navigate to your App Service in the Azure portal.
2. Under the "Monitoring" section, select "Application Insights".
3. Click "Turn on Application Insights".
4. Choose an existing Application Insights resource or create a new one.
5. Click "Apply".

Configuring Diagnostic Logs

You can configure diagnostic logs to capture detailed information about your App Service:

1. Navigate to your App Service in the Azure portal.
2. Under the "Monitoring" section, select "Diagnostic logs".
3. Choose the log categories you want to collect (e.g., AppServiceHTTPLogs, AppServiceAppLogs).
4. Select a destination for your logs, such as a Storage account, Log Analytics workspace, or Event Hub.
5. Click "Save".

Common Monitoring Metrics

Here are some of the most important metrics to monitor for your App Services:

Metric	Description	Typical Threshold
CPU Percentage	The percentage of CPU utilized by the App Service instance.	< 70-80% (sustained)
Memory Working Set	The amount of physical memory used by the App Service instance.	< 80% of allocated memory
HTTP 5xx Errors	The number of server-side errors (5xx status codes) returned by the application.	0 or very low
HTTP 4xx Errors	The number of client-side errors (4xx status codes) returned by the application.	Low and indicative of expected user behavior.
Requests	The total number of HTTP requests received by the App Service.	Monitor trends and spikes.
Response Time	The average time taken to respond to HTTP requests.	As low as possible, typically under 1-2 seconds.
Data In/Out	The amount of data transferred over the network by the App Service.	Monitor for unexpected spikes.

By leveraging Azure Application Insights and Azure Monitor, you can gain deep insights into the behavior of your app services, ensuring their stability and performance.