Getting Started with Citrix Licensing
Welcome to Citrix Licensing. This section provides details about how to license your Citrix product quickly and easily. It introduces you to the two major components that are part of the Citrix Licensing process: The Citrix License Server for Windows and the License Management Console. It provides you with a simplified overview of the licensing process and details the types of licenses available for Citrix products. It takes you through the step-by-step process of installing the licensing components and obtaining the license file needed to use your Citrix products.
Citrix eDocs contains information about Citrix Licensing, versions 11.5 and above. Earler versions are documented in the Citrix Knowledge Center.
Citrix recommends that you upgrade the license server to the latest version. Citrix does not provide hotfixes for license server components and does not support older license servers with newer products. The latest versions of the license server often contain resolutions to issues appearing in earlier versions. When you upgrade or install new Citrix products, upgrade the licensing components as well. New license servers are backward compatible and will work with older products and license files; however, new products often require the newest license server to check out licenses correctly. You can find the latest version from the Citrix Downloads site. If you are unsure if your license server version is current, you can verify it by comparing your version with the number on the Downloads site.
To find out which license server version you have, follow the below process:
Finding the License Server Version Number
If you are unsure if your license server is current, you can verify it by comparing your license server version number with the version number on. the Citrix Downloads site. Find your license server version in the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Citri\LicenseServer\Install
The version number appears in the format: 188.8.131.52 build 9014, When comparing version numbers, compare the numbers preceding the word build and the numbers following it.
Note: Use Registry Editor to view the license server information only. Editing the Registry can cause serious problems that may require you to reinstall your operating system.
- Log on to the computer where the licensing components are installed.
- Click Start > Run and type regedit.
- Navigate to HKEY_LOCAL_MACHINE\SOFTWARE(Citrix\LicenseServer\Install, The version number appears in the format: 184.108.40.206 build 9014.
About the Licensing Process
The following section provides a top-level overview of the licensing process. For a more detailed explanation of all of the daemons, files, and services that are part of the process but are not included here, see the Licensing: Architecture, An Overview white paper in the Citrix Knowledge Center.
When a user connects to a Citrix product, the product requests a license from the license server. When the license server grants the request, the product receives a license. This is known as checking out a license. When the user logs off from the product server, the product returns the license to the license server. This action is known as checking in a license.
Each time a Citrix product starts up, it opens a connection to the license server by checking out a startup license.
The startup license does not affect your license count. It is used to allow Citrix products to communicate with the license server using a continuous open connection. Every five minutes the license server and the products send a heartbeat message to each other to verify that they are mutually communicating.
Note: Some Citrix products can operate in a disconnected mode (not connected to the server). These products allow a user to check out a license and operate the product for a preconfigured period of time that is set by the administrator. In this case, heartbeat messages are not exchanged. One example of disconnected mode is when a user checks out a Password Manager license for a laptop, and then uses the laptop when it is not connected to the server.
If for any reason, a Citrix product cannot contact the license server to request a license, the product goes into a grace period. This grace period is set by Citrix and differs depending upon the product. The Windows Event Log displays messages that inform you if the product has entered the grace period, the number of hours remaining in the grace period, as well as a message that states that the grace period has ended and the product will stop accepting connections. Once communication is re-established between the product and the license server, a new message is displayed stating that the product has left the grace period.
Note: For products that operate in disconnected mode, the grace period takes effect after the preconfigured time specified for the license check-out expires.
The grace period allows the user to continue using the product for a specific period of time until the license server can exchange heartbeat messages with the product or, in the case of a user operating in disconnected mode, the user reconnects to the server.
Note: This grace period only takes place if the product has successfully communicated with the license server at least once.
Types of Licenses
Your product uses one of the following types of licenses (some products allow you to choose more than one type). It is important that you are aware of which types of licenses your company has purchased and how they are consumed. This ensures that you do not run out of licenses. The license types are:
User or device licenses
With XenDesktop 4, user or device licenses allow you to assign the license to a user or a device. When assigned to a user, the license allows access from an unlimited number of devices. When assigned to a device, the license allows access from the device by an unlimited number of users.
A licensed device requires a unique device ID and is authorized for use by any individuals to access instances of XenDesktop. Use this type of license for shared devices, such as classroom, hospital, or clinical workstations.
A licensed user requires a unique user ID, such as an Active Directory entry. You can reference these users and do not need to manage a separate or specific list of authorized users. When assigned to a user, the license allows the user to connect to their desktops and applications with multiple devices, such as desktop computer, laptop, netbook, smartphone, or thin client. A licensed user can connect to multiple instances of XenDesktop concurrently.
Concurrent user licenses
This type of license is not tied to a specific user. When a user launches a product, the product requests the license and it is checked out to the specific computer or device that the user is using. When the user logs off or disconnects from the session, the license is checked back in and is available for another user. Using this logic, keep the following scenarios in mind:
- Multiple sessions at different computers use multiple licenses. Each time a user launches a Citrix session from a different computer or device, a license is checked out until the user closes the session at that computer or device (at which point the license is checked back in). For example, if a user launches a session from one computer and then launches another from another computer (before closing the session on the first), two licenses are checked out.
- Because, license servers do not communicate with each other, if you are running multiple license servers you may consume more than one license (for example, with load balancing). If you are using load balancing, Citrix recommends that the product servers point to the same license server.
- Different editions consume different licenses. If a user connects to an application published on a computer running Advanced edition and then uses the same client to connect to an application published on a computer running Enterprise edition, two licenses are consumed.
- RDP connections consume a license (RDP connections to a console do not consume a license).
Concurrent system licenses
This type of license is similar to a concurrent user license; however, it is tied to a system, not a specific computer or device that the user is using.
When a user boots a computer or device and a system is launched (for example, an operating system or a virtual machine instance), a license is requested and checked out to the computer or device. The license remains in a checked out state until the system is no longer running (the computer or device is powered off or the virtual machine instance is stopped). Unlike a concurrent user license, the concurrent system license is not affected by a user logging on or off from a session; it is tied to the system’s power state (on or off).
Licenses are purchased on a per system basis; one license per running system is required.
Using this logic, keep the following scenarios in mind:
- Multiple systems running on a computer or device require one license for each system. For example, if a user is running two virtual machine instances on one computer, two concurrent system licenses are used.
- If a user is running one or more systems and logs off from a session, licenses are not released. The concurrent system license (or licenses) remains in a checked out state until the user powers off the computer or device (thereby closing the system connection to the computer or device) or stops the virtual machine instance.
Named user licenses
When a product requests a license, it is checked out to the user until a preconfigured period of time expires. This type of check-out is not tied to a computer or device; once the license is checked out, the user can run multiple sessions on different computers without checking out more licenses.
Posted in Citrix
How does a Citrix Presentation Server know what licenses you have when it loses connectivity to the license server?
One of the features of Citrix Presentation Server licensing that just about everyone knows about is that an individual Presentation Server will continue to function for 30 days after it loses connectivity to a Citrix License Server. Citrix does this in order to provide quasi-enterprise scalability of the licensing component, in that Presentation Servers in a multi-site farm will work for 30 days if the WAN link to the license server goes down.
But after 30 days, no new connections will be accepted.
This is cool, but it leads to the question, “How does the server know how many licenses I have and what’s allowed if it can’t contact the license server?”
Most people I’ve met over the years have assumed this information was stored in the zone’s data collector (and therefore in the IMA local host cache on each server). However this is NOT correct. In fact in PS3 or newer farms (with no XP servers), the zone data collector / local host cache do not maintain ANY licensing information.
Instead, information about Citrix Presentation Server licenses is “cached” locally on each member server in a file called mps-wsxica_mps-wsxica.ini, stored in the \Program Files\Citrix folder.
The wsxica_mps-wsxica.ini file is a simple text file. It contains a snapshot of the number, types, and expiration dates of the various licenses maintained in the licensing database. Here’s an example (with the CRC values changed, rendering this file not valid for actual use):
Anyone who’s ever looked through a .LIC license file from MyCitrix.com will notice some similarities to this INI file. The wsxica_mps-wsxica.ini file is created automatically on each Presentation Server the first time a server contacts the Citrix License Server, and it’s updated whenever any licenses are changed in the licensing database.
For the most part, knowing about this file and how it works is really anecdotal trivia. But there are a few important takeaways:
- If you ever have a problem where users are not able to login (with a licensing error) while your Presentation Server is not connected to the licensing server, now you know where to look. (Is this file present? Is it corrupt? Etc.)
- During a license server connectivity outage, yes, you can reboot your member Presentation Servers, and yes, you can reboot your data collectors. The mps-wsxica_mps-wsxica.ini file will stay put as long as you don’t actively delete it.
Posted in Brian Madden Blogs
More information about Licensing can be found at :
License Architecture an Overview
Introduction to Terminal Services
Some important points about Citrix Licensing:
- Citrix products update this record every hour.
- After a startup license is checked out by the Citrix product, the product and the license server exchange “heartbeat” messages every five minutes to indicate to each other that they are still up and running.
- For products that operate in disconnected mode, the grace period takes effect after the preconfigured time specified for the license check-out expires.
- The Citrix vendor daemon tracks the number of licenses that are checked out and which product has them.
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