_app-autoscaler.html.md.erb

To use App Autoscaler, you must create an instance of the service and bind it to an app.
To create an instance of App Autoscaler and bind it to an app,
see [Set Up App Autoscaler](../appsman-services/autoscaler/using-autoscaler.html#setup) in the _Scaling an Application Using App Autoscaler_ topic.

1. Click **App Autoscaler**.

    <%= image_tag("app-autoscaler.png") %>

1. Review the following settings:
    * **Autoscaler Instance Count**: How many instances of the App Autoscaler service you want to deploy.
    The default value is `3`.
    For high availability, set this number to `3` or higher.
    You should set the instance count to an odd number to avoid split-brain scenarios during leadership elections.
    Larger environments may require more instances than the default number.
    * **Autoscaler API Instance Count**: How many instances of the App Autoscaler API you want to deploy.
    The default value is `1`.
    Larger environments may require more instances than the default number.
    * **Metric Collection Interval**: How many seconds of data collection you want App Autoscaler to
    evaluate when making scaling decisions.
    The minimum interval is 60 seconds, and the maximum interval is 3600 seconds.
    The default value is `120`.
    Increase this number if the metrics you use in your scaling rules are emitted less frequently than the existing Metric Collection Interval.
    * **Scaling Interval**: How frequently App Autoscaler evaluates an app for scaling.
    The minimum interval is 15 seconds, and the maximum interval is 120 seconds.
    The default value is `35`.
    * **Verbose Logging** (checkbox): Enables verbose logging for App Autoscaler. Verbose logging is disabled by default. Select this checkbox to see more detailed logs. Verbose logs show specific reasons why App Autoscaler scaled the app, including information about minimum and maximum instance limits, App Autoscaler’s status. For more information about App Autoscaler logs, see [App Autoscaler Events and Notifications](../appsman-services/autoscaler/using-autoscaler.html#notifs).
    * **Disable API Connection Pooling**: If you select this option, the Autoscaler API does not reuse HTTP connections. This may be necessary if your [Frontend Idle Timeout](frontend-idle-timeout.html) for Gorouter is set to a low value, such as 1 second. 

1. Click **Save**.