Features
Related Warm-up
Pre-warm related apps when traffic arrives
Apps can declare relationships so that traffic to one pre-warms another in the background.
Configuration
["api.example.com"]
address = "127.0.0.1:3001"
command = "node api.js"
health_check = "/health"
also_warm = ["frontend.example.com"]
["frontend.example.com"]
address = "127.0.0.1:3002"
command = "node frontend.js"
health_check = "/"How It Works
When a request hits api.example.com, Penny starts frontend.example.com in the background, anticipating it will be needed soon.
The warmed app gets its own idle timer, if no direct traffic arrives, it shuts down after its wait_period as usual.
Use Cases
- API + Frontend: When users hit the API, they'll likely need the frontend too
- Microservices: Warm up downstream services when an upstream receives traffic
- Multi-app sites: Start related apps together to reduce overall cold start time