Dokku allows you to run multiple process types at different container counts. For example, if you had an app that contained 1 web app listener and 1 background job processor, dokku can, spin up 1 container for each process type defined in the Procfile. By default we will only start the web process. However, if you wanted 2 job processors running simultaneously, you can modify this behavior in a few ways.
Dokku expects this file to contain one line for every process defined in your Procfile. Example:
```
web=1
worker=2
```
## Use the ps:scale command. Example:
```
dokku ps:scale app_name web=1 worker=2
```
*NOTE*: Dokku will always use the DOKKU_SCALE file that ships with the repo to override any local settings.
## The web proctype
Like Heroku, we handle the `web` proctype differently from others. The `web` proctype is the only proctype that will invoke custom checks as defined by a CHECKS file. It is also the only proctype that will be launched in a container that is either proxied via nginx or bound to an external port.