Redundant License Server: License Balancing and License Server Backup

To understand how Sentinel RMS Development Kit uses redundant license servers to accomplish two goals: license server backup and license balancing lets consider the example below:

Imagine a wide-area network serving three basic groups of end users: the Sales Department, the Engineering Department, and the Accounting Department. Computers on this network might be in the same building, or might be in different cities or countries. You have a license code that permits 60 instances of a word processing application to run. The license code authorizes 60 licenses or that it has 60 tokens.

You select three computers on the network and install a license server on each. Typically, each license server computer is on the same subnet as the majority of the end users that will acquire licenses from it. (However, each license server may be on a different subnet.) For example, the Sales Departments’ computer is in the same building as the Sales employees, on the same part of the network used by those employees. This optimizes license management performance by speeding up license acquisition.

The license server computers do not have to be on the same subnet, license servers can be in geographically separate locations on subnets connected to one another via WAN, Internet, or dial-up connections. You decide to evenly distribute license tokens among all three license servers (20 each), assuming that each group of employees will use the protected application about the same number of times. This increases performance by distributing the load between multiple license servers.

However, if a group of employees ends up having a higher demand for licenses than the others, that group’s license server will borrow licenses from the other license servers automatically. This improves performance because users will be less likely to wait for a license from a distant license server.