Differences between redundant and distributed FLEXnet® license manager models

You are planning a network installation of an Autodesk program, and you want to know the differences between redundant and distributed license installations.

The following is a description of each type of server, as well as the advantages and disadvantages of redundant and distributed license installations. Autodesk Product Support strongly recommends the distributed server configuration for most applications.

Specific setup instructions for each license server model can be found in the help documentation located on the software installation media.

Redundant Server

With the redundant server model, you use exactly three servers to authenticate a single license file. One server acts as the master while the other two provide backup if the primary server fails. With this configuration, the system continues to monitor and issue licenses as long as at least two of the three servers are functional.

The redundant server configuration requires that all three license managers be located on the same subnet and be installed on the same server-based operating system. Mixing server operating systems or using workstation operating systems (such as Windows 2000, XP, or Vista) is not supported.

Advantages of redundant servers

• If a single server fails, all of the licenses will still be available.

Disadvantages of redundant servers

• If more than one server fail, no licenses will be available.
• All servers must be on same local subnet.
• It cannot be used to provide network fault tolerances. For example, if the network link between the server pool and a remote office is broken, no licenses will be available.
• It requires server-edition operating systems.
• It is complex to administer.
• The complete pool must be rebuilt in the event of a member server replacement.
• Unless you are actively monitoring the status of the servers, you may not know if one server has failed.

Distributed server

With the distributed server configuration, the available licenses are spread (distributed) across more than one license server. Each server functions independently. If one of the servers fails, the licenses on that server become unavailable.

Advantages of distributed servers

• Two or more servers supported.
• Servers may be distributed across a wide area network (WAN).
• It can be configured to provide network fault tolerance.
• As long as one server is working, at least some of the licenses will be available.
• Workstation or server operating systems may be used as license managers.

 Disadvantages of distributed servers

• If one server goes down, the licenses on that server will be unavailable.
• WAN technology suffers from latency and reliability issues.

Refer to the following video for an expanded explanation of different license server models:

Network Install of AutoCAD-Based 2011 Products