WebSockets for Tsung

A plugin for Tsung (http://tsung.erlang-projects.org/) for load-testing WebSockets servers.

Draws inspiration from the tsung_websocket project (https://github.com/onlychoice/tsung_websocket), various other Erlang WebSockets implementations and the Tsung plugin tutorial (http://www.process-one.net/en/wiki/Writing_a_Tsung_plugin/).

Why?

Why not just build on tsung_websockets? The reasons are:

• for some reason it didn't work out of the box
• it supports WebSockets as a transport protocol so you can run others like XMPP on top of it, and I didn't need that
• it includes a lot of unrelated code
• I wanted to try Erlang

Usage

Get the source and build dependencies for Tsung. On Debian use:

apt-get source tsung
sudo apt-get build-dep tsung

For Ubuntu or other distros you'll have to download the source from upstream:

sudo apt-get install erlang-nox python-matplotlib gnuplot libtemplate-perl openssh-client openssh-server
wget http://tsung.erlang-projects.org/dist/tsung-1.4.2.tar.gz
tar xzf tsung-1.4.2.tar.gz

Copy the DTD and provided Erlang files from tsung_ws to the Tsung source tree:

cp tsung_ws/tsung-1.0.dtd tsung-x.x.x/
cp tsung_ws/include/ts_websocket.hrl tsung-x.x.x/include/
cp tsung_ws/src/tsung_controller/ts_config_websocket.erl tsung-x.x.x/src/tsung_controller/
cp tsung_ws/src/tsung/ts_websocket.erl tsung-x.x.x/src/tsung/

Compile Tsung:

cd tsung-x.x.x/
./configure --prefix=$HOME/local/tsung
make install

Tsung uses SSH to launch monitoring and controller processes, make sure your user can connect to localhost without needing a password (this assumes you have generated an SSH key before):

cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys

Start the example Python WebSockets server (you will need Twisted and a fork of txWebSocket) and run Tsung using the provided configuration file:

sudo apt-get install python-twisted
sudo pip install -e git://github.com/wulczer/txWebSocket.git#egg=txWebSocket
cd ../tsung_ws/
python math_server.py
$HOME/local/tsung/bin/tsung -f websocket.xml -m /tmp/tsung.log start

After the run is done, you can generate an HTML report:

mkdir report
cd report
$HOME/local/tsung/lib/tsung/bin/tsung_stats.pl --stats /tmp/tsung.log

Loose ends

More error checking, handling continuation and binary frames, better logging.