How to Queue for Licenses

In RLM, queuing for licenses is under the software user’s control for well-behaved applications.

Unlike older license managers, RLM will queue for a license at every available license pool on every server, meaning you will not be stuck in a queue when there are licenses available on a server elsewhere.

In order to enable your application to queue for a license, set the environment variable RLM_QUEUE to any value. If RLM_QUEUE is set, the application will queue for its license if it is not able to check the license out on any license server. Once the application recognizes that the license has been granted by a server, it automatically de-queues the requests at all the other servers.

Note

This capability depends on your Software Provider having coded their application to handle the QUEUED status return from the license server.

Note

If you have set RLM_ROAM (or <ISVNAME>_ROAM), the setting of RLM_QUEUE is ignored.

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EXPRESS License Pools

RLM has the concept of an EXPRESS License Pool. If a license pool is marked as EXPRESS (the default), then queued requests which can be satisfied immediately are granted independent of whether other requests are ahead in the queue. If EXPRESS is turned off, then a queued request will always be placed at the end of the queue if there is a waiting request.

For more information on how to set up license pools as EXPRESS, see EXPRESS.

Since RLM applications queue at all license servers, a request for, say, 5 licenses, might take a long time to grant. In the meantime, up to 4 licenses could be available which could be granted to other applications which need only one license each. By setting some license queues to EXPRESS and turning off EXPRESS on others, you can bias the operation of different license servers to handle single or multiple license requests more favorably.