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.