Product Documentation

Improve performance by specifying thread use

Jan 15, 2013
Requests come in to the license server through a listener port. All communication must be accepted by an acceptance thread. If the message is accepted, a receive thread handles it and then a processing thread processes it. To improve license server performance when receiving a large number of requests, you can configure the maximum number of receive and processing threads to use.

When a program initiates an I/O request (an example would be a request to check-out a license), it creates and uses a thread. The thread maintains the place and data in the program as a reference point, and once the request is complete, the program can be re-entered at the same point. You can have many requests at the same time, depending upon how many threads are allowed. This is called multi-threading.

The optimal values needed for acceptable license server performance are dependent on the hardware, the site configuration, and the request volume. If you set the limits too high and your hardware cannot support it, it will slow down the communication. If you set the limits too low, it will take longer for the communication to occur as the system will wait until it can create more threads before it executes incoming requests. You should test and evaluate different values to determine the configuration that meets your site's needs. A good starting point for a large scale deployment might be setting the Maximum Number of License Server Manager Processing Threads to 30 and the Maximum Number of License Server Manager Receiving Threads to 15.
There are two areas where you can specify the thread limits:
  • License Server
  • Web Server

To set license server thread use

  1. In the top right corner of the console, click Administration.
  2. Click the Server Configuration tab and the License Server Configuration bar.
  3. Modify the Maximum Number of License Server Manager Processing Threads and Maximum Number of License Server Manager Receiving Threads fields (up to 999 threads).
  4. Stop and restart the Citrix Licensing service from the services control panel of the machine running the license server.

To set Web server thread use

Use this procedure to set the maximum number of threads that the Web server for the License Administration Console uses to process requests. Specify a larger number if you expect many users to simultaneously access the console.
  1. In the top right corner of the console, click Administration.
  2. Click the Server Configuration tab and the Web Server Configuration bar.
  3. Modify the Maximum Number of Web Server Threads field (up to 999 threads).
  4. Stop and restart the Citrix Licensing service from the services control panel of the machine running the license server.