scale.html.md.erb

---
title: Scale the App
owner: Tobias Fuhrimann
---

<strong><%= modified_date %></strong>

Currently, your app is running as a single instance with 128 MB of memory.

You can check how many instances are running and how much memory they have using the `cf scale` command:

<pre class="terminal">
$ cf scale my-nodejs-app
Showing current scale of app my-nodejs-app in org MyOrg / space MySpace as user@mydomain.com...
OK

memory: 128M
disk: 1G
instances: 1
</pre>

By default, your app is deployed as one instance. Each instance runs in a separate container and gets the set amount of memory.

## Scaling Horizontally

Scaling an application horizontally on <%= vars.product_full %> is equivalent to changing the number of instances that are running. Scale the number of instances to 3:

<pre class="terminal">
$ cf scale my-nodejs-app -i 3
Scaling app my-nodejs-app in org MyOrg / space MySpace as user@mydomain.com...
OK
</pre>

## Scaling Vertically

Scaling an application vertically on <%= vars.product_full %> is equivalent to changing the amount of memory each instance has. Scale the amount of memory to 256 MB:

<pre class="terminal">
$ cf scale my-nodejs-app -m 256M

This will cause the app to restart. Are you sure you want to scale my-nodejs-app?&gt; yes

Scaling app my-nodejs-app in org MyOrg / space MySpace as user@mydomain.com...
OK

...

     state     since                    cpu     memory          disk        details
#0   running   2016-03-30 04:54:46 PM   64.6%   72.6M of 256M   42M of 1G
#1   running   2016-03-30 04:54:47 PM   0.1%    69.9M of 256M   42M of 1G
#2   running   2016-03-30 04:54:47 PM   0.2%    69.7M of 256M   42M of 1G
</pre>

The last statement shows a summary of the three instances with a memory cap of 256 MB each that we now have.

<div style="text-align:center;margin:3em;">
  <a href="./dependencies.html" class="btn btn-primary">I know how to scale my App</a>
</div>