การติดตามและการบันทึกข้อมูล

When your applications run at the edge, they're distributed globally. This makes it challenging to know what's happening without good visibility.

Monitoring helps you track performance metrics like request times and error rates across your entire system. Logging gives you detailed records of individual events, like requests or errors, which are crucial for debugging.

The simplest way to log information in a Cloudflare Worker is by using console.log(). This works much like logging in a browser or Node.js environment.

Messages sent to console.log() are captured by Cloudflare and can be viewed in your Worker's dashboard or exported using Logpush.

Try running this Worker. It logs the incoming request's URL to the console. When you test it, check your Worker's logs in the Cloudflare dashboard to see the output.

While console.log() is easy, plain text logs can be hard to parse and analyze at scale. Imagine sifting through thousands of lines of text!

Structured logging involves outputting logs in a consistent, machine-readable format, like JSON. This makes it much easier for monitoring tools to process and query your logs.

Cloudflare's Logpush service allows you to export your Worker logs to various destinations, such as cloud storage (AWS S3, Google Cloud Storage) or analytics platforms.

This is essential for long-term storage, advanced querying, and integrating with your existing monitoring infrastructure.

Good structured logs contain useful context. Consider including:

• Timestamp: When the event occurred.
• Level: (e.g., INFO, WARN, ERROR) for severity.
• Request ID: To trace a single request through its lifecycle.
• URL & Method: Details of the incoming request.
• Latency: How long the operation took.
• Error Details: Stack traces, error messages.

This Worker logs request details as a JSON string, including a simple latency measurement. This format is easily parsable by log analysis tools.

While logs tell you 'what happened,' metrics tell you 'how much' or 'how often.' Metrics are numerical measurements captured over time, used to track the health and performance of your application.

Common metrics include requests per second, error rates, CPU usage, and memory consumption. They are aggregated and visualized in dashboards.

Cloudflare Workers provide built-in analytics, but you can also add custom metrics. One simple way is to use response headers to expose performance data that can be scraped or analyzed.

Here, we add a X-Worker-Latency header. More advanced metrics might use external services or Cloudflare's ctx.waitUntil to send data.

Once you have logs and metrics, you need tools to make sense of them. Cloudflare provides basic analytics, but for advanced analysis, you'll integrate with:

• Log Management Systems: Splunk, ELK Stack, DataDog, Sumo Logic.
• Monitoring Platforms: Grafana, Prometheus, New Relic, Dynatrace.

These tools help you visualize trends, set up alerts, and quickly identify issues.

You are debugging an intermittent error in your Cloudflare Worker. You've been using console.log("Error occurred!") to catch issues.

Which change would MOST improve your ability to diagnose the problem quickly?

Great job! In this lesson, you learned about the critical role of monitoring and logging for edge applications.

• console.log() is your basic logging tool.
• Structured logging (e.g., JSON) provides machine-readable, actionable insights.
• Cloudflare Logpush helps export logs for advanced analysis.
• Metrics track performance trends, often exposed via custom headers or dedicated services.
• Using external monitoring tools can greatly enhance visibility and debugging capabilities.

Keeping an eye on your edge apps ensures they perform optimally!