Load Testing in a Nutshell

There are plenty of freely available loading testing applications out there that can test the speed of a website with simulated load/users and the right one depends on your chosen platform. No matter which way you go, technique is just as important as technology:

Here’s a simple way to measure the concurrency of your website:

1. Run a load test - push your server to the point that errors occur to find its maximum capacity.
2. Double your server capacity.
3. Ensure that the server has been configured to use this full capacity.
   (Some applications impose their own limits on how much resource they use.)
4. Run a load test - push your server to the point that errors occur to find its maximum capacity.

The resized server should be able to handle significantly more load than the original - assuming you have only a single server - then things like the operating system of the server won’t take up more space on a larger server and so your “free capacity” should have more than doubled.

Here’s a simple way to measure the scalability of your website:

1. Run a load test - push your server to the point that errors occur to find its maximum capacity.
2. Increase the size of your site with test or junk content.
   (Take a backup first, you want to be able to get back to where you were!)
3. Run a load test - push your server to the point that errors occur to find its maximum capacity.

The more data you pump into the system, the slower it will get. If you see no slow down at all you’re either not adding enough stuff or your system has capacity to spare - keep going.

The point of a load test is not to pass - it’s to fail under as much load as possible in the most graceful way possible. If your software didn’t break, you didn’t test it hard enough.