General WebpageTest questions

Hi. I have a few questions regarding WebpageTest - I’m not even sure which forum to post them in…

1 - Arquitechture
As I understood so far, WebpageTest’s arquitechture is this:

  • A web server running Apache, running the website we can download (currently webpagetest_2.10/www) - I’ll call it the “Controller”.
  • One or more agents/test machines that execute the browsing tests (installed and configured with the stuff in webpagetest_2.10/agent) - I’ll call these the "Agent"s.
  • There is one standard controller ( and several agents working for it (probably from and from «partners»).
  • We can run new agents and have them work for’s controller, as a «partner» of
  • We can install our own arquitechture of controller + agents.

The agents will HTTP poll the controller they’re configured to use from time to time, looking to receive work assignements.
Then, they will execute any work assignment.
Then, they will HTTP post a zipped file with the results back to the controller.

#1 - Is this correct?

2 - Hosting a Test Location

#2a - These instructions are to host an agent only, to join’s partner network, right?

“Once I have the necessary information I will configure the new location on the server and provide the testing software properly configured.”
#2b - What does it mean “provide the testing software properly configured”? Isn’t the software already installed and configured in the AMI instances? Does it mean that if we install an agent from scratch (from webpagetest_2.10/agent) you will provide us the configurations - as in not really the software?

3 - RDP
“If you RDP into the system, reboot after you are done so the desktop does not remain locked”
#3 - Will executing a “Log off” suffice or do we really need to reboot? Also, will the agent successfully run the tests while we’re activelly RDP’ing an agent?

4 - Test locations
As far as I understood, «locations» are just logical groupings of agents for usage convenience (choosing which group - location - to execute the test from), taking no further effect.
#4 - Is this correct?

5 - Test Machine(s) / agents

“Create a shortcut to c:\webpagetest\wptdriver.exe in the startup folder”
#5a - Is the path “c:\webpagetest” mandatory or just an example?
#5b - The wptdriver.exe executable will be the actual agent (polling the controller for work and executing it), right?

“The test agents will automatically update their code from the server if there are update files in place (in /work/update on the server).”
I assume that we can put the new files in the folder /work/update (unpacked) and the agents will replace the files with the new ones.
#5c - Won’t that replace all the different .ini files in the agents with the single new .ini files (I’m assuming the agents might have different .ini files with different, for ex, location settings).

6 - Desktop version / Hosted Pagetest
I see 2 different forums, one named “Desktop version”, and another named “Hosted Pagetest”. I’m assuming they relate to 2 different ways of usage of WebpageTest!?
#6 - What are the differences between Desktop version and Hosted Pagetest?

Yes, correct.

Yes, correct. Otherwise you just want to use the private instance docs:

If you are deploying the software on machines, not using the AMI images I just provide the location and key information already configured. You’re also welcome to do the private install setup and configure the location and key manually (or if you are using AMIs then I will provide the user data string with the relevant information).

You really do need to reboot. A “Log Off” will cause windows to lock the desktop which will prevent screen shots and video capture from working. The agent will run tests while you are RDP’d to it but the performance may not be representative since it will be remoting the paints over RDP.

Yes, though in the case of, they are grouped by physical location. Sometimes I have multiple instances of the same physical locations if there is test equipment from different providers so that the results from a given location will always be consistent.

Just an example - it can live wherever you’d like.

Yes, mostly. It relies on wpthook.dll as well which it injects into the browser to do the actual measurement but wptdriver.exe handles the workflow.

There is a specific structure to the update files. They are zip files with an accompanying ini file and the entire update is in the zip file. You can see what it looks like here:

The ini files are not included in the updates (at least the ones I do) so the configurations do not get overwritten.

Yes - I should probably kill the “Desktop version” section since it hasn’t been supported for quite a long time. The IE plugin (pagetest.dll) has a UI that you can use locally and it will display waterfalls, etc. It hasn’t been officially supported for several years but it’s still functional.