---
layout: docs
page_title: 'Autoscaling Plugins: Pass-Through'
description: The "pass-through" strategy plugin passes the query result directly to the target.
---

# Pass-Through Strategy Plugin

The `pass-through` strategy is a very simple, yet useful strategy. It does not
add any extra computation on top of the metric query result, and instead uses
the APM query result as the scaling count. It doesn't have any configuration
options.

This allows the Nomad Autoscaler to be integrated into systems where the
scaling computation is done externally like an edge router, or easily derived
from a query such as running one allocation per item in a queue.

## Agent Configuration Options

```hcl
strategy "pass-through" {
  driver = "pass-through"
}
```

## Policy Configuration Options

```hcl
check "pass-through-check" {
  # ...
  strategy "pass-through" {}
  # ...
}
```

- `max_scale_up` `(int: unlimited)` - Specifies the maximum number of instances
  that can be added in a single scaling operation. It acts as a safeguard
  against the system scaling up too rapidly.

- `max_scale_down` `(int: unlimited)` - Specifies the maximum number of instances
  that can be removed in a single scaling operation. It acts as a safeguard
  against the system scaling down too rapidly.
