The Financial Firewall: Multi-Cloud HA on a $0 Budget

Most “High Availability” setups are expensive. We designed a pattern that makes HA actually save you money.

How the Waterfall Works

Instead of a simple “Round Robin” load balancer, Crate uses a Priority-Based Waterfall.

[ REQUEST ] 
    |
    v
[ CRATE GATEWAY ] (Bare Metal / Fixed Cost)
    |
    |----(A) Try Primary Backend (On-Prem / Bare Metal) ----> [ SUCCESS ]
    |
    |----(B) IF (A) Fails OR Overloaded --------------------> [ FALLBACK: AWS/GCP ]
    |
    |----(C) IF (B) Fails ----------------------------------> [ STATIC STATUS 503 ]

By capping the “Primary” capacity and only “bursting” to the cloud when absolutely necessary, you create a financial firewall. You never get a $10,000 surprise bill because the system is designed to fail safe on a fixed budget.

By configuring Crate to prioritize cloud “Free Tiers” (like those from Cloudflare, Vercel, or Fly.io) and only failing over to paid instances when quotas are hit, you create a natural financial buffer.

Key Benefits:

• Automatic Failover: If your primary provider goes down, Crate shifts traffic instantly.
• Quota Management: Crate tracks request counts to ensure you stay within free limits before hitting your main “Burn” tier.
• Safety: No more $10k surprise bills from a misconfigured scraper.