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How do I survive the stampede?

As a performance tester, I am always surprised to see how unprepared most retail websites are. Even when load testing has been done (to prepare for sales or marketing campaigns), most of the time it is nowhere close to the real users behavior. We've already seen the importance of response times in a previous article, but there are other aspects we should consider.

For instance, unless you spent the past years on a different planet, you have probably seen these videos where thousands of people rush into stores during sales. There is no reason why thing would happen differently on a retail website. So the question is how do I survive the stampede?


Focus on what you already know

As obvious as it may seem, you should start by analyzing your users behavior. If this is not your first rodeo, you probably know what to expect. Also, websites like google analytics will give you an idea of what should happen. But never underestimate the importance of analyzing this data.

REST API using Node.js

I want to setup a simple REST server that allows to Create, Read, Update and Delete data (Users in this case) using Node.js, Express, and TypeScript:

  • I could do it using Java/Spring in a couple of minutes, but I want to learn more about Node.js.
  • Express seems to be a good choice to create REST APIs.
  • And as I think that TypeScript may be the good compromise between Java and Javascript I will keep on giving it a try.

Also, I would like to feel as comfortable as using Java. First I need a debugger. No need to spam console.log() using node-inspector. Then unit tests are mandatory and cannot go without a code coverage tool. Finally, I make use of various tools to build, test, debug and run the TypeScript code. Grunt is convenient simplify these processes (plus it's a gain for productivity).
The only thing I bypassed is a code quality tool. We use SonarQube on a daily basis for OctoPerf, and I might do the same for this sample someday.

Before reading this article further, you may check the result on GitHub Rest-Crud.

AngularJs domain name filter

Until now, we used default names such as 'Untitled VU' for virtual users created in octoperf, our load testing tool. That's not very relevant. So we changed it to the domain name of the tested website.

The load tester selects a URL to test, and we need to extract the domain name from it.

A nice trick is to create an hyperlink element <a href="..."/>. Then we can retrieve the hostname, parsed by the browser. So instead of relying on a regex we use the browser built-in URI parsing capabilities. It's easier and safer.

TypeScript using WebStorm

We use AngularJs at, for the frontend of our load testing tool. As AngularJs V2 quick start guide uses TypeScript, I think it's a good motivation to give it a try.


Node.js and npm must be installed to run this sample. WebStorm is used to automatically transpile our .ts files (compile them to .js ones).

We can also use the command line transpiler:

  • npm install -g typescript to install it.
  • tsc --watch -m commonjs greeter.ts to transpile it.

Base tools for bloggers

To follow up on my article about creating blog based on Jekyll, Bootstrap4, Grunt, Bower and hosted on GitHub pages, I'm adding ways of measuring and increasing the number of visitors.

This article is a quick tutorial to do the same, starting from the blog template:

  • Get to know how many visitors are caught in your blog using Google Analytics,
  • Generate a Sitemap.xml using Jekyll and feed it to Google,
  • Embed Twitter buttons,
  • And use Disqus to handle your articles comments.