How to configure automatic failover routing on Vercel

Navigate to your Vercel dashboard and create multiple projects or deployment environments. Go to Projects → New Project and deploy your application to different regions or create separate backup deployments. Ensure you have at least one primary and one backup deployment with different URLs.

In your Vercel dashboard, go to Storage → Edge Config → Create Store. Name your store (e.g., 'failover-config') and create it. This will store your routing configuration and health check settings that can be accessed globally at the edge.

Create health check API routes in your application by adding files like /api/health.js:

export default function handler(req, res) {
  res.status(200).json({ status: 'healthy', timestamp: Date.now() });
}

Deploy this to all your target environments to enable automated health monitoring.

Create a middleware.js file in your project root:

import { get } from '@vercel/edge-config';
import { NextResponse } from 'next/server';

export async function middleware(request) {
  const config = await get('failover-config');
  
  if (config?.enableFailover) {
    // Check primary service health
    const healthCheck = await checkHealth(config.primaryUrl);
    
    if (!healthCheck.healthy) {
      return NextResponse.redirect(config.backupUrl);
    }
  }
  
  return NextResponse.next();
}

In your Edge Config store, add the following configuration:

{
  "enableFailover": true,
  "primaryUrl": "https://your-primary-app.vercel.app",
  "backupUrl": "https://your-backup-app.vercel.app",
  "healthCheckInterval": 30000,
  "timeout": 5000
}

Click Save to apply the configuration.

Go to your project settings → Environment Variables → Add New. Add EDGE_CONFIG as the key and paste the connection string from your Edge Config store. Apply this to all environments (Production, Preview, Development).

In your project settings, go to Domains and configure your custom domain to point to your primary deployment. Set up DNS records with your domain provider to use Vercel's nameservers. This ensures failover routing works with your custom domain.

Deploy your changes and test the failover by temporarily disabling your primary service. Monitor the behavior using Vercel's Functions → Logs section. Set up monitoring alerts by integrating with services like DataDog or using Vercel's built-in analytics to track failover events.