Azure Host Pool Deployment and Optimization

Azure Host Pool deployment can be a complex process, but with the right approach, you can simplify it.

To start, you need to create a host pool in the Azure portal, which can be done by clicking on the "Host pools" tab in the Azure Bastion service.

A host pool is essentially a collection of virtual machines that can be used to provide a seamless desktop experience to your users.

You can scale your host pool up or down as needed, with the ability to add or remove virtual machines from the pool.

Azure Host Pool supports multiple desktop experience options, including Windows 10 and Windows 7.

By using Azure Host Pool, you can improve the security of your virtual desktop infrastructure by isolating your virtual machines from the underlying infrastructure.

To create an Azure host pool, you need an existing host pool with a session host configuration. This is a crucial step, as it will serve as the foundation for your Azure host pool.

You'll also need an existing host pool with standard management, which must only contain session hosts on Azure or on Azure Local. Mixing session hosts on Azure and on Azure Local in the same host pool is not supported.

All session hosts in a host pool should have the same configuration, including the same identity provider. For example, a host pool shouldn't contain some session hosts joined to Microsoft Entra ID and some session hosts joined to an Active Directory domain.

The Azure account you use must have the Desktop Virtualization Host Pool Contributor, Virtual Machine Contributor, and Azure Stack HCI VM Contributor roles on the resource group.

Here are the specific actions and roles required:

To ensure a smooth process, don't disable Windows Remote Management (WinRM) when creating and adding session hosts using the Azure portal, as PowerShell DSC requires it.

If you want to add session hosts on Azure Local or deploy session hosts to Azure Extended Zones, additional requirements apply.

Lastly, if you plan to use the Azure CLI or Azure PowerShell locally, make sure you have the desktopvirtualization Azure CLI extension or the Az.DesktopVirtualization Azure PowerShell module installed, or use Azure Cloud Shell.

When setting up an Azure host pool, it's essential to configure it properly to ensure seamless user experience.

The Configuration tab is where you'll find the host pool configuration properties. You should be familiar with them from when you created a host pool. The load balancer configuration is crucial in distributing user sessions across available hosts.

Here are some key configuration properties to examine on the Configuration tab:

To configure load balancing, you'll want to start by examining the host pool configuration properties on the Configuration tab. This is where you'll find the load balancer, limit number of sessions on host, power on host on-demand, and validation environment properties.

To configure load balancing with the Azure portal, sign in to the Azure portal, enter Azure Virtual Desktop in the search bar, and select the matching service entry. Then, select Host pools, followed by the name of the host pool you want to configure, and select Properties.

The Azure portal allows you to select the load balancing algorithm from a drop-down menu and enter a value for the max session limit. You can also update the load balancing settings using the Update-AzWvdHostPool cmdlet in Azure PowerShell or the az desktopvirtualization hostpool update command in Azure CLI.

The breadth-first load balancing algorithm is ideal for organizations that want to provide the best experience for users connecting to their remote resources. It works by querying session hosts in a host pool that allow new connections and then selecting a session host randomly from half the set of available session hosts with the fewest sessions.

The depth-first load balancing algorithm, on the other hand, aims to saturate one session host at a time. This algorithm is ideal for cost-conscious organizations that want more granular control on the number of session hosts available in a host pool. You must set a maximum session limit when using the depth-first algorithm.

Here's a comparison of the two load balancing algorithms:

To make sure the setting has updated, you can run a command in Azure PowerShell or Azure CLI to retrieve the current load balancing settings for the host pool.

Adding new VMs from a new image is a crucial step in updating your Azure Virtual Desktop environment. You'll need to generate a registration key for the new image.

To do this, search for your hostpool in the Azure Portal and click on the resource. Click on Registration key and then Generate new key. Set a date and time for the key, just long enough to add the new VM, and click OK. Copy the generated key and close out the registration.

Next, click on Session hosts and then click + Add button. Select the new image you created and click Next: Virtual Machines. Here's a summary of the steps:

After the deployment is finished, the new servers are added to the Windows Virtual Desktop Host pool, created with the latest version of the custom image.

To add session hosts to your Azure Virtual Desktop host pool, you can use the Azure portal and specify the number of session hosts you want to add. Azure Virtual Desktop will automatically create them based on the session host configuration.

You can't use PowerShell to add session hosts to a host pool with a session host configuration. Instead, you need to follow these steps: sign in to the Azure portal, select the host pool you want to add session hosts to, and then select Session hosts and click + Add.

If you created virtual machines outside of Azure Virtual Desktop, you'll need to register them as session hosts to a host pool. This involves installing the Azure Virtual Desktop Agent and the Azure Virtual Desktop Agent Boot Loader on each virtual machine, and using the registration key that you generated.

The Autoscale feature in Azure Virtual Desktop is a game-changer for managing your session hosts. It allows you to scale your hosts based on demand, ensuring that your users always have a seamless experience.

To access Autoscale, you'll need to be in the host pool settings. If your host pool has Template as a provisioning type, you'll see the Autoscale tab. From there, you can select a template or create a new one by clicking the Create new button.

The Autoscale settings work similarly to those for RD Session Host groups, but with a few key differences. In Azure Virtual Desktop, we're dealing with hosts and host pools, whereas in RD Session Host groups, we talk about servers and groups.

Here are the steps to enable Autoscale:

Note that Autoscale settings will only be available if you have a template specified for your host pool. If not, you'll need to create a template first.

Breadth-First Load Balancing is a great way to distribute user sessions across session hosts, optimizing for session performance. This algorithm is ideal for organizations that want to provide the best experience for users connecting to their remote resources.

The breadth-first algorithm first queries session hosts in a host pool that allow new connections. It then selects a session host randomly from half the set of available session hosts with the fewest sessions.

For example, if there are nine session hosts with 11, 12, 13, 14, 15, 16, 17, 18, and 19 sessions, a new session doesn't automatically go to the session host with the fewest sessions. Instead, it can go to any of the first five session hosts with the fewest sessions at random.

Due to the randomization, some sessions may not be evenly distributed across all session hosts. However, this algorithm is still a good choice for organizations that want to provide a great user experience.

To configure breadth-first load balancing, you can use the Azure portal, Azure PowerShell, or Azure CLI. Here's a brief overview of the steps:

To create session hosts with Virtual Desktop Service (VDS), you can use the Azure portal. You can specify the number of session hosts you want to add, and Azure Virtual Desktop will automatically create them based on the session host configuration.

To register session hosts to a host pool, you need to install the Azure Virtual Desktop Agent and the Azure Virtual Desktop Agent Boot Loader on each virtual machine and use the registration key that you generated. The registration key authorizes session hosts to join the host pool.

You can generate a registration key by using the Azure portal, Azure PowerShell, or Azure CLI. To generate a registration key using the Azure portal, sign in to the Azure portal, navigate to the host pool, select Registration key, and click Generate new key.

To add new VMs to a host pool from a new image, you need to create a new registration key, add the new VMs to the host pool, and then update the VMs with the latest version of the custom image.

Here's a step-by-step guide to creating and registering session hosts with VDS:

1. Create a new registration key using the Azure portal, Azure PowerShell, or Azure CLI.

2. Install the Azure Virtual Desktop Agent and the Azure Virtual Desktop Agent Boot Loader on each virtual machine.

3. Use the registration key to register the virtual machines as session hosts to the host pool.

4. Add the new VMs to the host pool using the Azure portal.

5. Update the VMs with the latest version of the custom image.

Note that you can also use automated deployment tools, such as Intune or Configuration Manager, to install the Azure Virtual Desktop Agent and the Azure Virtual Desktop Agent Boot Loader from the command line.