All your urls will need to check for the special argument in the url: ?user_id=x
If you see that argument, then you bypass the normal login sequence and instead set x as your currently logged in user by storing it in your session variable.
Reporting
Keep a careful lab notebook!
Make note of configuration changes that you try
Collect data and try to interpret it
When your app is failing to scale
Think about what happens when your app response time is longer than
the time between new connections. Requests will start to pile up.
If it takes too long for a request to reach the front of the line, it
will time out.
If your app is too overloaded, it may shut down entirely. Make sure
to consult your Heroku logs after a test to identify this.
When an app hasn’t been accessed for a while, Heroku will put it in a
sleep state. If your app is asleep, make sure to access it manually
to wake it up before beginning a test. Waking up may take several
seconds, which would influence your results.
Using Loader.io
Our goal is to see how well each of your servers survive the onslaught of traffic