Install modules dependencies with:
$ npm install
and run the app with:
$ node app.js
Point your browser to http://localhost:3001 and you should see a grid of 100x100 black squares.
From command line, doing a GET http://localhost:3001/10/20/ff0000 you will change the color of the square at position 10,20 to the color #ff0000. I know it should be a PUT.
$ wget http://localhost:3001/10/20/ff0000
Then from command line you can use Siege to run a load test like this
$ siege -c 200 -f Troll-face-urls.txt