Intermediate LevelNode JS

How do you build production health check endpoints using process.uptime() and memory metrics?

❓ Interview Prompt: Build /health endpoints returning HTTP 200 with JSON payload containing process.uptime() (in seconds), process.memoryUsage(), and database connection status.

Production orchestrators (Kubernetes, AWS ALB) rely on HTTP '/health' endpoints to monitor service readiness and liveness:

Metrics to Expose:

•

'process.uptime()': Service running time in seconds.

•

'process.memoryUsage().heapUsed': Active heap RAM.

•

Database Connectivity: Health check query on DB connection pool.

Code Implementation Example

javascript

import http from 'node:http';
import mongoose from 'node:mongoose';

http.createServer(async (req, res) => {
  if (req.url === '/health') {
    const isDbConnected = mongoose.connection.readyState === 1;
    const statusCode = isDbConnected ? 200 : 503;

    res.writeHead(statusCode, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({
      status: isDbConnected ? 'UP' : 'DOWN',
      uptimeSeconds: Math.floor(process.uptime()),
      memoryHeapMB: (process.memoryUsage().heapUsed / 1024 / 1024).toFixed(2)
    }));
  }
}).listen(3000);

💡Building production health check endpoint in Node.js.

🎯 Interview Key Takeaway

Return 503 status on health check endpoints if critical database connections or downstream dependencies fail.

#health check#process.uptime#Kubernetes#Intermediate

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