# Auto-scaling & Scaling to Zero

> Configure scaling limits, concurrency targets, and scale-to-zero variables.

- **Category**: Deploy & Configure
- **Last Verified**: 2026-07-14

Because Kubeletto runs Knative, it scales container instances based on active concurrent request volume.

## Scaling Configurations

- **Min Instances**: Minimum active instances. On the free tier, this MUST be `0` (enforcing scale-to-zero).
- **Max Instances**: Cap on the maximum instances the horizontal scaler can spawn.
- **Concurrency Target**: The threshold of concurrent requests handled by one instance before scaling out.

## Deploying Scaling Limits

```bash
kubeletto deploy my-service --image my-image:latest --min-instances 0 --max-instances 3
```

## Understanding Scale-to-Zero

When a service receives no requests for 60 seconds, Knative routes scale down container instances. The next incoming request triggers a "cold start," which loads container layers and starts your application. Cold starts usually take between 2 to 8 seconds.