> ## Documentation Index
> Fetch the complete documentation index at: https://cerebrium-fix-make-entrypoint-docs-explicit.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Gradual Roll-out

> Control the transition between revisions during deployments

<Note>This feature is available from CLI version 1.38.2</Note>

The `roll_out_duration_seconds` parameter in the `[scaling]` section of your `cerebrium.toml` file controls how quickly traffic transitions between revisions after a successful build.

## Overview

When you deploy a new version of your app, Cerebrium creates a new revision. The `roll_out_duration_seconds` parameter determines how long it takes to transition traffic from the old revision to the new one.

Traffic is shifted in 5 batches of 20% each, over the specified duration. This gradual transition helps ensure a smooth user experience and minimizes disruptions.

## Configuration

Add the `roll_out_duration_seconds` parameter to the `[scaling]` section of your `cerebrium.toml` file:

```toml theme={null}
[scaling]
roll_out_duration_seconds = 0  # Default value
```

## Parameters

* **Valid range**: 0-600 seconds
* **Default value**: 0 (immediate transition)

## Best Practices

* **Development environments**: Keep the value at 0 during development for immediate transitions
* **Production environments**: Use lower values to optimize cost and resources while ensuring smooth transitions
* **High-traffic applications**: Consider using higher values for gradual transitions to minimize disruption