Health Endpoint

ELI5 — The Vibe Check

A health endpoint is a simple URL (usually /health or /healthz) that returns 'I'm alive and everything's fine' or 'something's broken.' Load balancers and Kubernetes check this constantly to know if your server is healthy. It's your app's heartbeat monitor.

Real Talk

A health endpoint is an HTTP endpoint that reports the application's operational status. Basic health checks return 200 OK if the process is running. Deep health checks verify dependencies (database, cache, external services). Used by load balancers, orchestrators, and monitoring systems for automated health verification and traffic routing decisions.

Show Me The Code

app.get('/health', async (req, res) => {
  try {
    await db.query('SELECT 1');
    await redis.ping();
    res.json({ status: 'healthy', uptime: process.uptime() });
  } catch (err) {
    res.status(503).json({ status: 'unhealthy', error: err.message });
  }
});

When You'll Hear This

"The load balancer checks /health every 10 seconds and removes unhealthy instances." / "Add database and Redis checks to the health endpoint, not just a 200 OK."