Supervision et journalisation
Configurez la supervision et la journalisation de vos applications en périphérie pour suivre leurs performances et diagnostiquer les problèmes.
Supervision et journalisation est une leçon Edge Computing with Cloudflare Workers & Deno gratuite sur CoddyKit. Ceci est la leçon 3 sur 4. Tu peux lire la leçon complète ci-dessous gratuitement — puis la pratiquer en direct dans le navigateur avec un éditeur de code intégré et un tuteur IA 24/7. Elle fait partie du parcours d'apprentissage Edge Computing with Cloudflare Workers & Deno, et ta progression se synchronise sur le web et l'application CoddyKit. Le cours Edge Computing with Cloudflare Workers & Deno comprend 4 leçons au total.
Certaines parties de cette leçon n'ont pas encore été traduites et s'affichent en anglais.
Why Monitor & Log Edge Apps?
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.
Basic Logging: console.log
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.
Basic Logging in Action
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.
export default {
async fetch(request, env, ctx) {
console.log("Request received for:", request.url);
return new Response("Hello from basic logging!");
}
};The Need for Structured Logs
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 Logpush Overview
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.
What to Include in Logs?
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.
Structured Logging Example
This Worker logs request details as a JSON string, including a simple latency measurement. This format is easily parsable by log analysis tools.
export default {
async fetch(request, env, ctx) {
const start = Date.now();
const response = new Response("Hello from structured logs!");
const latency = Date.now() - start;
const logEntry = {
timestamp: new Date().toISOString(),
level: "INFO",
url: request.url,
method: request.method,
latencyMs: latency,
requestId: crypto.randomUUID()
};
console.log(JSON.stringify(logEntry));
return response;
}
};Introduction to Edge Metrics
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.
Custom Metrics in Workers
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.
export default {
async fetch(request, env, ctx) {
const start = Date.now();
const response = new Response("Hello from custom metrics!");
const latency = Date.now() - start;
// Add a custom header as a simple metric
response.headers.set("X-Worker-Latency", latency.toString());
console.log(`Request processed in ${latency}ms`);
return response;
}
};Monitoring Tools & Dashboards
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.
Quick Check on Logging
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?
Recap: Monitoring & Logging
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!
Questions Fréquemment Posées
La leçon « Supervision et journalisation » est-elle gratuite ?
Oui — le texte complet de « Supervision et journalisation » est gratuit à lire ici sur le web. Pour la pratiquer de manière interactive (un éditeur de code intégré et un tuteur IA 24/7) et déverrouiller le reste du cours Edge Computing with Cloudflare Workers & Deno, passe à CoddyKit PRO. Le cours Edge Computing with Cloudflare Workers & Deno comprend 4 leçons au total.
Qu'est-ce que j'apprendrai dans « Supervision et journalisation » ?
Configurez la supervision et la journalisation de vos applications en périphérie pour suivre leurs performances et diagnostiquer les problèmes. Tu pratiques Edge Computing with Cloudflare Workers & Deno avec du code pratique que tu exécutes directement dans le navigateur, et un tuteur IA 24/7 répond à tes questions au fur et à mesure que tu avances dans la leçon.
Dois-je avoir de l'expérience pour commencer Edge Computing with Cloudflare Workers & Deno ?
Aucune expérience préalable n'est requise. Edge Computing with Cloudflare Workers & Deno sur CoddyKit est structuré pour les débutants jusqu'aux apprenants avancés, donc tu peux commencer ici ou depuis le début et avancer à ton rythme. Ceci est la leçon 3 sur 4.
Combien de temps prend la leçon « Supervision et journalisation » ?
La plupart des leçons CoddyKit prennent environ 5–10 minutes. Chacune est courte et interactive, tu progresses régulièrement et tu repiques exactement où tu t'es arrêté sur le web et l'app.
Peux-tu écrire et exécuter du code dans cette leçon Edge Computing with Cloudflare Workers & Deno ?
Oui. Chaque leçon Edge Computing with Cloudflare Workers & Deno inclut un éditeur de code intégré, tu écris et exécutes du vrai code directement dans ton navigateur et tu reçois des retours IA instantanés — aucune configuration locale requise.
Toutes les leçons de ce cours
- Stratégies de mise en cache
- Démarrages à froid et préchauffage
- Supervision et journalisation
- Taille du paquet et optimisation du code