By Greg Holmes
One problematic area for Citrix XenApp (and other application virtualization technology) customers is how to ensure they buy the correct numbers of software licenses for products they deploy and use from their Citrix servers. While the licenses they buy from Citrix are quite straightforward, the licenses for virtualized applications that they use in this environment can be troublesome to count, particularly if some users are also using the apps locally on their desktops as well. Since every third party vendor would look on this kind of deployment differently, enterprises need accurate methods to count each type of license. License optimization tools that help count the usage and license consumption can be very beneficial and help avoid over-counting.
There is often an overlap between licenses used in a Citrix environment and those used in other end user environments, such as the traditional desktop. For instance while a Citrix farm might make MS Office available for all users, some users may already have a local install and consume a license for that device, which also covers them for the Citrix virtualized application delivered to the same device (desktop, laptop, etc.). The examples below illustrate that depending on the license model and usage scenario, different numbers of licenses are consumed. In the first case, a User based license will consume only 1 license for 2 devices, whereas a Device based license requires 2—one for each device. In the second scenario, only one license is required to access both the local installation and the virtual application, regardless of whether the license is User based or Device based.
Figure 1 - Examples of Licensing Scenarios in a Citrix XenApp Environment
Why is this important?
A customer with just under 5,000 employees, including about 1,000 users who also access their software via Citrix, was recently trying to calculate their license consumption under all of the above scenarios. For some titles they were getting numbers greater than 5,000, even though users were meant to be able to leverage their license for a locally installed copy. The numbers were obviously wrong, but how could they work out an appropriate license level? In addition, some of these titles weren’t used by all users, so just buying one copy for each employee would have been expensive and also the wrong approach.
They needed to come up with a better way of calculating the consumption of licenses for a combination of locally installed software and virtualized applications, without wasting money on unnecessary additional licenses.
How is it different from a traditional software environment?
In a traditional software environment, companies are used to the problem of just counting the number of software installs on the physical hardware. In a Citrix XenApp virtualized application environment, the application software isn’t installed on the end-point device, so it doesn’t show up in inventory. To solve this problem, some organizations are using next generation software asset management and license optimization products to collect application virtualization data from the Citrix server—for example, information on users with access rights to the virtualized applications and possibly, the actual usage data, if the Citrix Edgesight tool is also in use. This information can be combined with regular inventory from the end users’ machines to find out:
- Who has a local copy of the application on their desktop or laptop
- Who uses the software via Citrix XenApp
- Who could use the software via Citrix XenApp (i.e. has access rights)
This information gets reconciled against the entitlement data from purchase orders and software agreements. Organizations can determine whether an additional license is needed for each Citrix user or whether the license allocated to the device for the local copy is going to cover the virtual usage. The application usage data can also tell them which users have access to the software in Citrix but don’t ever use it. That way, administrators can tighten up access through ACL permissions on the Citrix servers.
With the Citrix XenApp, Edgesight and end-point inventory data, the license optimization tool can be used to accurately manage virtualized application licenses. These tools also apply license entitlements—product use rights, including virtual use, to ensure that license consumption is minimized and no unnecessary licenses are purchased.
What is the result for customers?
The customer mentioned above was able to uncover license entitlements that had previously not been utilized—meaning they had bought more than enough licenses for their current needs. They also discovered other situations where the additional licenses required were much fewer than they expected. For some titles, they needed 1000 less licenses than they had thought.
They were also able to tighten up access to applications and are using automation to only grant access to users in Citrix XenApp where they require it. This has resulted in significant cost avoidance and cost savings on licenses for virtualized applications.
How are you managing licenses for your virtualized applications?
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