MATLAB Installation Guide for Windows    

Configuring Redundant License Servers

If a large number of licenses are governed by a single license server, failure of the server becomes a major event. To prevent problems, you may want to set up redundant servers so that, if one server goes down, the license manager can still function.

In the redundant server configuration, three systems are designated to be license servers. All three systems must be running at the time the license manager is started. However, once the license manager is running, only two systems need to be running at any time; this is called a quorum. As long as a quorum exists, the license manager can continue to run.

Selecting Servers

The first step in configuring the license manager is choosing the servers. When choosing servers, keep in mind:

License Files in Redundant Configurations

Once you have chosen the servers, determine the host IDs of each server and provide them to The MathWorks when you request your License File. The MathWorks will generate an appropriate License File.

The following example shows a License File that supports redundant servers. Note that the License File has three SERVER lines that identify each of the three redundant servers.

After you install the license manager on all the server systems in the redundant configuration, you must edit the processed License File, $MATLAB\flexlm\license.dat, created during these installations. The installer only adds the first SERVER line to the License File during the installation. You must add the additional SERVER lines. Make sure to include the names, host IDs, and IP addresses of the other systems in the redundant configuration in these additional SERVER lines, as shown in the example. Put a copy of this edited License File in the $MATLAB\flexlm directory on all of the systems in the redundant configuration.

Starting License Manager Daemons in Redundant Configurations

You must start the license manager on each system in the redundant configuration and wait for the license manager daemons on the three systems to synchronize with each other. This may take a few minutes. If, for some reason, the license manager daemons do not connect, take the daemons down on each machine, and rerun the procedure. Network traffic may affect the synchronization, so it may require several attempts to establish a proper connection. Again, all three machines must connect for the license manager to begin serving keys. Once the daemons are up and connected on all three machines, only two machines are needed for a quorum; the loss of any one machine will not cause any licenses to be revoked.


  Running MATLAB with Other FLEXlm Applications Troubleshooting