---
layout: docs
page_title: Checks
sidebar_title: Checks
description: Learn about how the Autoscaler deals with policy checks.
---

# Nomad Autoscaler Check Calculations

A scaling policy can include several checks all of which produce a scaling
suggesting. The checks are executed at the same time during a policy evaluation
and the results can conflict with each other. In a scenario like this, the
autoscaler iterates the results the chooses the safest result which results in
retaining the most capacity of the resource.

In a scenario where two checks return different desired directions, the following
logic is applied.

- `ScaleOut and ScaleIn => ScaleOut`
- `ScaleOut and ScaleNone => ScaleOut`
- `ScaleIn and ScaleNone => ScaleNone`

In situations where the two same actions are suggested, but with different counts the
following logic is applied, where the count is the absolute desired value.

- `ScaleOut(10) and ScaleOut(9) => ScaleOut(10)`
- `ScaleIn(3) and ScaleIn(4) => ScaleIn(4)`
