Tutorial: Installation of the LoadGen Core Agent

Linux

1. Login to your Linux machine.
2. Start the Terminal.
3. Check which version of Linux you run with the command lsb_release -a

Ubuntu 20.04

For setting up the LoadGen Core Agent on a system running Ubuntu 20.04, follow these steps:

1. Set the correct package location (check this article, too: https://docs.microsoft.com/en-us/dotnet/core/install/linux-ubuntu):
   

        wget https://packages.microsoft.com/config/ubuntu/20.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
   sudo dpkg -i packages-microsoft-prod.deb
   rm packages-microsoft-prod.deb

2. Now install the dotnet runtime:
   

        sudo apt-get update
   sudo apt-get install -y apt-transport-https
   sudo apt-get update
   sudo apt-get install -y dotnet-runtime-8.0

3. Copy the LoadGen files, we use the /usr/local/bin location to set up the LoadGen Core Agent:
   

        cd /usr/local/bin
   sudo mkdir loadgen
   sudo chmod a+rwx loadgen
   cd loadgen

4. Start the LoadGen Core Agent with the following command:
   

        dotnet LoadGen.Core.Agent.dll

Ubuntu 22.04

Following the release of .NET Core for Linux, it was initially unavailable in the official Ubuntu repository. Consequently, many users opted to add the Microsoft APT repository to install it. However, .NET Core packages have since been added to the Ubuntu repository, leading to conflicts between the Microsoft and Ubuntu packages.

The resolution is simple: you need to choose either Microsoft or Ubuntu packages to avoid mixing. This article will guide you through sticking with the Microsoft packages. We suggest this because Microsoft is likely to provide more frequent updates.

Firstly, clean your system by removing all existing packages related to .NET Core:

sudo apt remove dotnet*
sudo apt remove aspnetcore*
sudo apt remove netstandard*

Next, create a file in /etc/apt/preferences.d. The file name should follow the convention of starting with a two-digit number to ensure a predictable sorting and loading order. For instance, you can name the file 99microsoft-dotnet.pref. The content of this file should be as follows:

echo "Package: *" | sudo tee /etc/apt/preferences.d/99microsoft-dotnet.pref
echo "Pin: origin \"packages.microsoft.com\"" | sudo tee -a /etc/apt/preferences.d/99microsoft-dotnet.pref
echo "Pin-Priority: 1001" | sudo tee -a /etc/apt/preferences.d/99microsoft-dotnet.pref

After setting your preference for Microsoft packages, update and install .NET Core SDK 6.0:

sudo apt update
sudo apt install dotnet-runtime-8.0

Alternatively, if you prefer to use the official Ubuntu packages, follow the removal step above instead of creating an entry in /etc/apt/preferences.d, remove the Microsoft repository:

sudo rm /etc/apt/sources.list.d/microsoft-prod.list
sudo apt update
sudo apt install dotnet-runtime-8.0

Please note that the Microsoft repository contains other packages, such as PowerShell, SQL Server Command-Line Tools, and more. Removing this repository might not be ideal if you rely on these packages.

Copy the LoadGen files, we use the /usr/local/bin location to set up the LoadGen Core Agent:

cd /usr/local/bin
sudo mkdir loadgen
sudo chmod a+rwx loadgen
cd loadgen

Start the LoadGen Core Agent with the following command:

dotnet LoadGen.Core.Agent.dll

LoadGen Core Agent running as a Service

In addition to its direct running capabilities, the LoadGen Core Agent can be set up to operate as a persistent service on a Linux system. This enables the agent to run continuously in the background, independent of user sessions, and automatically start on boot. This is particularly useful for maintaining long-term, uninterrupted load testing, especially in environments where routine user interaction is not feasible or efficient. The following steps will guide you on how to set up the LoadGen Core Agent as a service on your Linux machine.

It's important to note that the current version of LoadGen Core Agent operates specifically in desktop session 0, as determined by the $DISPLAY environment variable. This is a common setup in many Linux systems, where the first display that's started is assigned the value 0.

We understand the need for more flexible configurations to cater to various testing environments. Therefore, we are pleased to announce that an update is in the works for an upcoming release. This will extend the functionality of LoadGen Core Agent to support other display sessions beyond 0. This enhancement is part of our commitment to continuously improve and adapt to the needs of our user community.

1. SSH into the Linux machine and copy the files within the LoadGen Core Agent from the LoadGen Director installation path (C:\Program Files\LoadGen\LoadGen Director) to the Linux machine /usr/local/bin/loadgen.
2. Create a service file into /etc/systemd/system/LoadGen.Core.Agent.service with the following content -- Make sure you add the correct user in the file:
   

         [Unit]
   Description=LoadGen.Core.Agent
   After=network.target
   StartLimitIntervalSec=10
   
   [Service]
   Type=simple
   Restart=always
   ResetSec=1
   User={User logged in GNOME}
   ExecStart=dotnet /usr/local/bin/loadgen/LoadGen.Core.Agent.dll
   
   [Install]
   WantedBy=multi-user.target

3. Enable the service: Sudo systemctl enable Loadgen.Core.Agent
4. Start the service: Sudo systemctl start LoadGen.Core.Agent

LoadGen Core Agent for WebTesting

LoadGen's WebTesting feature allows users to conduct performance and load testing directly from a user's perspective. Available from Q2-2023, our updated LoadGen Core Agent supports multiple browsers, such as Chrome, Chromium, Microsoft Edge, Firefox, and, from Q3-2023 onwards, even Webkit. This allows you to record, convert, and validate user interactions, including clicks, typing, and other activities within your web applications, bringing you accurate insights into your application's user experience.

Additionally, our Core Agent allows you to effortlessly use variables and data sources to feed data into your Software as a Service (SaaS) applications, helping you to simulate more realistic user interactions. One of the key capabilities of the LoadGen Core Agent is measuring the wait time associated with user actions, a critical metric when gauging user experience and overall application performance.

However, please take note of the $DISPLAY environment variable when setting up the LoadGen Core Agent. In its current iteration, LoadGen operates on desktop session 0. Support for other display sessions is planned for an upcoming release. If your environment doesn't permit switching to desktop session 0, there's no need to worry. You still have the option to adjust your load test profile and enable headless mode. Headless mode allows your tests to run without a display environment, making it a practical solution when working in non-interactive session conditions or when display access is restricted.

Before we dive into the specifics of setting up LoadGen Core Agent for WebTesting, it's worth mentioning the importance of having a solid network infrastructure. The LoadGen test infrastructure components, including the LoadGen Director and LoadGen Core Agents, require seamless network communication to perform optimally. In cases where these components are set up across different networks, a Site-to-Site VPN might be required to ensure secure communication. Read more about network traffic here.

One of the key components of WebTesting using LoadGen Core Agent is its ability to streamline the testing process by enabling you to make certain preparations before running your first test. For instance, you can save time by pre-emptively preparing the WebTesting feature for your Linux environment. This can be done by running the following command:

This command primes the LoadGen Core Agent for WebTesting and ensures that when you run your first test, you won't encounter any unnecessary delays. Press CTRL-C to stop the LoadGen.Core.WebRecorder.

Another benefit of LoadGen Core Agent is its support for the Microsoft Edge browser on Linux environments. You can install Microsoft Edge directly within the directory where the LoadGen Core Agent is stored, typically /usr/local/bin/loadgen, by executing the following command:

This command facilitates the installation of Microsoft Edge in your Linux environment, offering greater flexibility and testing options. Once you've successfully installed Microsoft Edge, it's critical to manually launch the browser and complete all initial setup steps before initiating a test. This ensures that any introductory prompts or configurations are properly addressed, allowing your tests to run smoothly.

Once you've successfully installed the necessary browsers and prepped the WebTesting feature, you can start the LoadGen Core Agent by executing the following command:

Installing Google Chrome on Ubuntu - NO ARM

The following instructions will guide you through installing Google Chrome on your Ubuntu machine. Please note that Chrome is not built for ARM processors, so if you want to run LoadGen WebTesting on a Rasberry Pi, for example, use Chromium (sudo apt install chromium-browser).

1. Start by opening the Terminal application. You can easily find this by searching for "Terminal" in Ubuntu's application launcher or pressing Ctrl + Alt + T to launch it.
2. Next, you need to download the installation file for Google Chrome. Execute the following wget command in Terminal, which will fetch the latest version of Google Chrome:
   

   wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb

3. Once the download is complete, proceed to install Google Chrome using the dpkg command as shown below:
   

   sudo dpkg -i google-chrome-stable_current_amd64.deb

4. Should you come across an error indicating that there are missing dependency packages, resolve this by running:
   

   sudo apt-get install -f

5. At this point, Google Chrome should be successfully installed on your system. You can open it either by entering google-chrome-stable the Terminal or by clicking the Google Chrome icon, which can be found in Ubuntu's application launcher.

Running a Web Test from SSH Terminal

During the execution of a web test from a Secure Shell (SSH) terminal session, you might encounter the following error:

This error typically arises when you attempt to run a graphical user interface (GUI) based browser without an active XServer, which is required to render the GUI on Linux systems.

While it is possible to run a web test from an SSH session, the "Headless browsing" option must be enabled in the LoadGen Director to bypass the need for an XServer. This option enables the browser to run in a headless environment, essentially without a visible GUI, minimizing the overhead associated with a full-fledged desktop session.

Here's how to enable headless browsing:

1. Launch the LoadGen Director.
2. Open your active canvas.
3. Proceed to the tab page Target Environment.
4. Choose Headless browsing.

Once you've enabled headless browsing, the web tests should execute smoothly from your SSH terminal. If you want to verify the progress of your tests, you can enable the "Send screenshot to database" option from the LoadGen Studio. This feature captures screenshots at specified points during the test, providing a visual reference to assess if the test is proceeding as expected.

Resolving System.IO.IOException in LoadGen Core Agent on Linux

In some cases, while running the LoadGen Core Agent on Linux systems, you might encounter an error similar to this:

This error indicates that the maximum user limit for inotify instances, or the per-process limit for open file descriptors, has been reached. Inotify is a Linux mechanism for monitoring changes to the filesystem, and each inotify instance consumes system resources.

To resolve this issue, you can increase the limit of inotify instances. Here's how to do it:

1. Open your Linux terminal.
2. Switch to the root user by entering the following command:
   

   sudo -i

3. Then, add a new limit for the maximum user instances of inotify by entering:
   

   echo fs.inotify.max_user_instances=524288 >> /etc/sysctl.conf

4. This command writes the line fs.inotify.max_user_instances=524288 at the end of the sysctl.conf file, which sets the maximum user instances of inotify to 524288.
5. Type exit to break out the root user context.

By increasing this limit, you can run the LoadGen Core Agent without encountering the error.

Resolving System.Net.Sockets.SocketException in LoadGen Core Agent on Linux

During the operation of the LoadGen Core Agent on Linux systems, you might encounter the following error:

This error usually arises due to a mismatch in the time zone configuration between the LoadGen Director, which initiates the test, and the Linux LoadGen Core Agent.

A discrepancy in time zones can lead to communication issues between the different components of the LoadGen infrastructure. A straightforward solution to this issue is to align the time zones on all systems involved in the test.

Here's how to adjust the timezone on your Linux machine using the timedatectl command:

1. Open your Linux terminal.
2. Check the current system’s timezone by running the following command:
   

   timedatectl

3. To find out the full name of the timezone, use the command:
   

   timedatectl list-timezones

4. The naming convention for time zones usually follows the Region/City format.
5. You can narrow down the timezone list by combining the timedatectl command with the grep command to filter the search using the name of a city, like so:
   

   timedatectl list-timezones | grep Paris

6. Press CTRL + C to exit the list.
7. Once you've identified the correct timezone, update your system's timezone with the following command:
   

   sudo timedatectl set-timezone [timezone]

8. Replace [timezone] with the name of your desired timezone.
9. To verify that the timezone has been updated successfully, run:
   

   timedatectl

10. The output should reflect the new local time and timezone.

By ensuring the timezones across your LoadGen infrastructure align, you can run the LoadGen Core Agent without encountering the 107 error.

Resolving System.Security.Cryptography.CryptographicException in LoadGen Core Agent on Linux

If you encounter a System.Security.Cryptography.CryptographicException error in the LoadGen Core Agent on Linux may be due to a corrupted cache file. To resolve this issue, follow these steps:

1. Open a terminal and locate the cache file by running:
   

   find / -name Core-msalcache.bin
   find / -name credentials.bin

2. Remove the identified file using the rm command:
   

   rm /path/to/Core-msalcache.bin
   rm /path/to/credentials.bin

Restart the LoadGen Core Agent to apply the changes. This should resolve the error and allow the Core Agent to function correctly.

Resolving FATAL ERROR: ENOENT: no such file or directory, mkdtemp 'C:\Users\%USERNAME%\AppData\Local\Temp\2\playwright-artifacts-XXXXXXXXXXXX

When encountering the error message 'FATAL ERROR: ENOENT: no such file or directory, mkdtemp 'C:\Users\%USERNAME%\AppData\Local\Temp\2\playwright-artifacts-XXXXXXXXXXXX', it indicates that the system is attempting to create a temporary directory for Playwright artifacts but cannot find the specified path.

Verify the Existence of the Directory Path:

1. Ensure that the directory C:\Users\%USERNAME%\AppData\Local\Temp\2 exists.
2. If it does not exist, manually create the missing folders.

Permissions:

1. Verify that your user account has the permissions to create directories and files within the Temp directory.

By ensuring that the full path C:\Users\%USERNAME%\AppData\Local\Temp\2 exists and is accessible, you can resolve the ENOENT error and allow Playwright to create the necessary temporary directories for its operations.

Windows

1. Install the dotnet runtime 6.0 client (https://docs.microsoft.com/en-us/dotnet/core/install/windows?tabs=net60).
2. Login into the Windows machine and copy the files within the LoadGen Core Agent from the LoadGen Director installation path (C:\Program Files\LoadGen\LoadGen Director) to the Windows machine C:\Program Files\LoadGen\LoadGen Core Agent.
3. Make sure you auto-login on the Windows machine (https://docs.microsoft.com/en-us/troubleshoot/windows-server/user-profiles-and-logon/turn-on-automatic-logon).
4. Make sure you auto-start the LoadGen.Core.Agent.exe (https://support.microsoft.com/en-us/windows/add-an-app-to-run-automatically-at-startup-in-windows-10-150da165-dcd9-7230-517b-cf3c295d89dd).

LoadGen Core Agent for WebTesting

LoadGen's WebTesting feature allows users to conduct performance and load testing directly from a user's perspective. Available from Q2-2023, our updated LoadGen Core Agent supports multiple browsers, such as Chrome, Chromium, Microsoft Edge, Firefox, and, from Q3-2023 onwards, even Webkit. This allows you to record, convert, and validate user interactions, including clicks, typing, and other activities within your web applications, bringing you accurate insights into your application's user experience.

Additionally, our Core Agent allows you to effortlessly use variables and data sources to feed data into your Software as a Service (SaaS) applications, helping you to simulate more realistic user interactions. One of the key capabilities of the LoadGen Core Agent is measuring the wait time associated with user actions, a critical metric when gauging user experience and overall application performance.

Before we dive into the specifics of setting up LoadGen Core Agent for WebTesting, it's worth mentioning the importance of having a solid network infrastructure. The LoadGen test infrastructure components, including the LoadGen Director and LoadGen Core Agents, require seamless network communication to perform optimally. In cases where these components are set up across different networks, a Site-to-Site VPN might be required to ensure secure communication. Read more about network traffic here.

One of the key components of WebTesting using LoadGen Core Agent is its ability to streamline the testing process by enabling you to make certain preparations before running your first test. For instance, you can save time by pre-emptively preparing the WebTesting feature for your Windows environment. This can be done by running the following command:

This command primes the LoadGen Core Agent for WebTesting and ensures that when you run your first test, you won't encounter any unnecessary delays.

Once you've successfully installed the necessary browsers (make sure you install Google Chrome if you want to run a test with Chrome as the preferred browser) and prepped the WebTesting feature, you can start the LoadGen Core Agent by executing the following command: