Product Documentation

Back up

Mar 16, 2015

Depending on how crucial the applications associated with your licenses are, you may want to create backup license servers. Although Citrix stores backup copies of your licenses, downloading many replacement licenses can be time-consuming. You can either store backup licenses on a network file share or have a configured backup license server ready in case of license server failure.

Grace periods

If the product cannot contact the license server due to a power outage or network problem, it continues to operate for the grace period as though all licenses are available. If the product cannot contact the license server by the end of this period, the product stops accepting client connections until communication with the license server resumes. See your product’s administrator guide for specific details on its grace period.
Note: Existing connections are never disconnected when the product enters the licensing grace period. When the grace period expires, only new connections are denied.
Some notes about licensing grace periods across Citrix products:
  • When a Citrix product goes into a licensing grace period, an event is written to the Windows Event Log on the computer running the product.
  • When a product enters the licensing grace period, Citrix XenApp Management Pack for Microsoft Operations Manager 2005 raises an alert. (Writing the grace period event to the Windows Event Log triggers this alert.)
  • When Password Manager enters the licensing grace period, it does not write any errors to the Windows Event log. Instead, warning messages start appearing on the user’s desktop. You can tell if a user entered the licensing grace period by checking the information contained in the user’s notification area icon.

Redundancy solutions

Setting up redundancy solutions might be necessary only in mission-critical environments. For smaller or less mission-critical deployments, you can back up your license server by creating a duplicate license server that can be stored on or off the network. For larger, more mission-critical deployments, you might want to create a clustered license server.

You can ensure redundancy for your license server by:
  • Duplicating the license server and its contents - Give the duplicate computer the same name as the active license server and store it off the network.
  • Using a network applicance - If you are using only one license server to service license requests at any time, you can use a network appliance that detects server or network outages and route traffic to a backup license server.
  • Storing an additional license server on the network with a different server name - In this case, when the active license server fails, you need to change the backup server name to start using it as the active license server.
  • Creating a clustered license server. For more information about clustering and licensing, see Setting up the License Server on a Microsoft Cluster.
All methods let you exchange one server license for another without a loss of service, provided the exchange occurs within the grace period. There are key points to remember:
  • Because license files reference the server specified during allocation, you can use the files only on a server with the same binding information (server name or FQDN or Ethernet address) as the original license server
  • You cannot have two license servers with the same name on your network active at the same time
  • You must add any additional licenses that you download to both the active license server and the backup license server