Load balancing Remote Desktop Services using Pen


Load balancing Remote Desktop Services using Pen, a load balancer for “simple” tcp based protocols such as http or smtp.
It allows several servers to appear as one to the outside and automatically detects servers that are down and distributes clients among the available servers. This gives high availability and scalable performance.

Pen Installation

We will use CentOS for this example:

yum install pen

You can also build it from source but this is not in the scope of this tutorial.

Run Pen on Startup

Pen supports a config file located at /etc but in order to use pen for multiple port balancing you will need to launch it manually.
We have created a manual startup command and added it to /etc/rc.d/rc.local
You will need to add this command for every Port you want to balance.

Pen Command Overview

-w - Web export file location
-x - Amount of session
-l - Log file location
-C - Local Port (Make sure it is not used by anything else)
-S - Amount of servers
-r - Remote Port to balance

Load balancing Remote Desktop Services using Pen

You can use Pen to load balance Remote Desktop sessions – port 3389,
To enable on startup – add this command to /etc/rc.d/rc.local:


/usr/bin/killall pen
/usr/bin/pen \
-w /var/www/html/stats.html \
-x 500 \
-l /var/log/pen.log \
-C \
-S 4 \
-r 3389 \ \ \ \

Pen Web Interface

Pen supports exporting session information to an html page so you can enable httpd and monitor the sessions and servers status:

Enable httpd:

yum install httpd
chkconfig httpd on
service httpd start

Create an update script

vi /scripts/penwebd.sh

press “a” to get into edit mode and paste your content.


/usr/bin/penctl status > /var/www/html/index.html

use “esc” and then “shit+q” and finally save with “x” press enter.

Schedule script to run periodicity:

use “crontab -e” to edit crontab:

*/1 * * * * root /scripts/penwebd.sh


Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.