Introduction
In January 2023, VMware released an updated version of their primary desktop virtualization platform – Horizon 8 2212 (first two numbers for the year of release, second two – for the month). Amongst many novelty functions of this solution, one has particular importance for large enterprises that apply published app infrastructure based on RDSH and Citrix XenApp. Meet Apps on Demand for published apps! Today we are going to take a look at how exactly this technology allows companies to save serious money on the support and maintenance of said apps.
What Is It?
First of all, it did not come out of the blue. App Volumes On-Demand Applications technology has appeared in previous Horizon releases as well (it was announced even earlier, way back in 2019). It allows users to create ready-to-use applications delivered through App Volumes technology, which are launched on demand thanks to connecting virtual volumes in real time.
Until just recently, the On-Demand Applications function used to not mount VMDK with apps while starting the VM, but to leave the app icons on the desktop. Clicking on those icons starts the dynamic mounting of the volumes, building connections, and loading the app into the OS. No more spending time on mounting disks while the VM is being started. This speeds up the logging in of a user significantly.
What’s so different about this release? Well, it does the same thing for published apps. You can apply it to the apps published by Horizon Apps, Citrix Virtual Apps, and Microsoft Remote Desktop Session Host (RDSH)/terminal as well. That also includes legacy apps which can be delivered to various devices (smartphones or MacBooks, for example) only that way.
The main feature that makes this approach really great is the possibility of keeping fewer servers powered on. You can just launch how many you may require whenever the need arises. This is a significant step forward from the classic “always on” concept for apps, and supporting such infrastructure costs WAY less.
Modern data centers equipped by large enterprises have a lot of apps (and their versions) distributed between on-premises and cloud locations. These apps are often available to their users within the framework of server farms, organized on the base of such services as Citrix Virtual Apps (formerly XenApp) and Microsoft RDSH. They translate the app image to the user’s desktop in a way that it looks like to be installed locally (whereas, for example, a Windows app can be delivered to the macOS desktop).
Terminal products like this usually go through a lot of optimization based on criteria for user experience and channel efficiency. However, the one huge problem is that all of these servers need to stay turned on, applications need to be installed and updated, and admins are stuck with supporting this whole infrastructure.
That is why it is so important that the App on Demand for published apps approach enables the user to launch applications on server farms only when required.
How Does it Work?
Let’s take a look at how this works, shall we?
Originally, this functionality was built upon the App Volumes solution, just as the previous On-Demand Applications technology within popular VMware’s concept known as Apps Everywhere.
What’s the gist? It’s practically the same: a user addresses an app located, for example, on the RDSH server farm, the volume with an app is mounted to server farm node’s VM, downloaded to the server memory, and delivered to a user on demand within this particular session.
The new host is launched only when the last working host reaches its limit, which is set by the IT department.
Firstly, it’s up to the admin to decide which apps from application pools will be available to selected users/groups:
After this, assigned users will see in their devices’ Horizon Client environment (which can be a smartphone screen) the icons of available apps:
After clicking on the application’s icon, this app starts on a server for this specific session of this specific user (if necessary, it will be preliminary mounted using App Volumes means) and is delivered to a desktop as if it is working locally:
The same goes for Windows apps and macOS devices:
This approach is especially useful for legacy applications. Usually, they only work on Windows, but some users do require access from their devices (laptops or phones) whenever they are out of the office for work matters. The important thing is that for every separate session an individual copy of an app is launched for security reasons; VMDK disks with required apps are mounted to the server on demand (whenever the first copy is launched). Thanks to this, the system only needs to support copies ready for work instead of dozens of sessions.
If there’s a need to scale application infrastructure for VMware Horizon, just add a new App Volumes Manager:
Next, associate it with the required farm, and all of the apps within will be automatically added to the VMware Horizon environment with no further actions needed:
Eventually, add the application pool from the selected App Volumes Manager and pick installed apps that will be available within the Published Apps pool:
At this stage, you can also set application names that will appear on the icons and in windows’ titles:
Finally, here’s how VMware describes the supposed roles of participants in the Apps on Demand for published apps workflow within the infrastructure of published apps:
That is the significant economic effect that Apps on Demand for published apps is going to bring to the industry. When there’s a large number of server farms with a huge list of several applications (and their versions), the Apps on Demand approach will save servers’ resources since there’s no need to keep applications on, waiting for the user’s session. Moreover, the VMDK disk with a particular app will itself be mounted only on the first demand.
All of this lets you limit the number of server farms that support the infrastructure of the apps. In turn, that means less work for admins in terms of support and maintenance. The only thing you’ll need to update is the VMDK disk image which has applications installed (and that is a pretty straightforward process if done with the App Volumes). By the way, users still have access to the copy/paste operations, opening apps in the browser, Component Object Model (COM)/OLE/ActiveX, and shared registry keys.
To Sum Up
Apps on Demand within the App Volumes solution enables you to separate the layer of OS and the apps, which, in turn, simplifies the dynamic delivery of the apps. Practically, you don’t have to maintain the whole IT infrastructure at a given time because the OS and the apps work independently from each other. App Volumes is a universal solution that supports 99% of applications. All you need to do is find an app installer that works with such formats as EXE, MSI, ZIP, or JAR (portable versions will work too as well as Microsoft MSIX standard packages).
Another important thing is that such infrastructure works both on-premises and in the cloud (Microsoft Azure Virtual Desktops). Thanks to this, big enterprises can now build hybrid environments where supporting EUC (end user computing) infrastructure is largely automated.
You can try App Volumes and see for yourself if you follow this link. Good luck!
