replit-reliability-patterns

# Replit Reliability Patterns ## Overview Production reliability patterns for Replit's container-based hosting. Replit containers restart on deploy, sleep on inactivity (Autoscale), and have ephemeral filesystems. These patterns ensure your app survives container lifecycle events gracefully. ## Prerequisites - Replit Deployment configured - External storage for persistent state (PostgreSQL or Object Storage) - Understanding of Replit container lifecycle ## Container Lifecycle ``` Container starts → App boots → Handles requests → [Sleep or Restart] │ ┌────────────────────────────────────┘ │ ┌───────┴──────┐ │ Sleep trigger │ Autoscale: no traffic for ~5 min │ Restart trigger│ Deploy, config change, or crash └───────┬──────┘ │ State lost: filesystem, in-memory data, caches State kept: PostgreSQL, KV Database, Object Storage, Secrets ``` ## Instructions ### Step 1: Graceful Startup ```typescript // Handle cold starts — prioritize accepting requests over initialization import express from 'express'; const app = express(); let ready = false; // Accept requests immediately app.listen(parseInt(process.env.PORT || '3000'), '0.0.0.0', () => { console.log(`Server started in ${process.uptime().toFixed(1)}s`); // Initialize in background initialize().catch(console.error); }); // Health endpoint...