For each simulated request that Webserver Stress Tool sends to the server, one arrow is shown in this chart.
Each arrow represents one hit (i.e. one HTTP request). The black arrows are pages (i.e. HTML files), the green arrows represent images, the blue arrows show frames and the red arrows show failed requests.

This sample chart shows clicks to several URLs with HTML pages (single black arrow) and pages with frames and images (black arrow with blue arrows). There are also some failed requests (red arrows).

The longer a request took, the further right the arrow ends. As soon as the HTML text of a page request is received, the images are requested from the server and shown in the chart with the green arrows.
Notice the red arrows which represent failed PAGE requests.
Here is an older example of a hierarchy graph:

It shows the request hierarchy for one user to a website. The website has a homepage URL such as “www.company.com“ which redirects to a frameset. In this view, the arrow is the first request to the company URL. The request is then redirected to a frameset page (second arrow), which consists of several HTML pages/frames (blue arrows). The html pages of each frame then has their images (green and red arrows).
In total a visitor of this webpage needed at least 5 seconds for the complete page to load. That’s very slow…
Webserver Stress Tool is a powerful HTTP-client/server test application designed to pinpoint critical performance issues in your web site or web server that may prevent optimal experience for your site's visitors.
Welcome
Introduction: Testing Basics
Performance, Load or Stress Testing?
Calculation of Load and Load Pattern
Webserver Stress Tool Features
How much load can Webserver Stress Tool generate?
Installation
Configuring Webserver Stress Tool
Selecting the Test Type and the Number of Users
Selecting the URLs or Editing the URL Script
Using Custom URL Scripts for Advanced URL Sequences
Performance Tips&Tricks
Running the Test
Reviewing Logfile Results
Analyzing Graphical Results
Graph Click Times & Errors (per URL)
Graph Click Times, Hits/s and Clicks/s
Graph Server and User Bandwidth
Creating Reports
Additional Features
Appendix
Software License and Contact Information