LICENSE QUEUING in RLM

RLM Transition Strategies

QUEUING DONE RIGHT
The Reprise License Manager (RLM) gives end-users unprecedented control over license queuing.

License Queuing Basics
Concurrent licensing enables a large user population to share software licenses rather than requiring each user to have his or her own license. Consequently, there can be contention for the licenses among the users. License queuing refers to a managed process that provides fair access to product licenses when all concurrent licenses for that product are in use. This happens when the number of users wanting a license exceeds the number of licenses available.  This situation is not necessarily bad.  It is akin to "music-on-hold" when there are not enough available support representatives when you contact a call-center.  It is often financially impractical to ensure that there will never be a wait for service. Similarly, software users often tolerate waiting for software when it is not cost-effective to deploy a dedicated license for each potential user.
 
Licensing without Queuing
Floating or concurrent RLM licenses are pooled within and across license servers. When an application starts up, it contacts a license server to request  a number of licenses (typically 1) that it needs to run. RLM grants a license from the first license server that can satisfy the request. If there not enough licenses to satisfy the request, then the application gets a status code that indicates this condition.  Typically, the user would be notified, and a retry might be attempted, or the program might terminate gracefully. Queuing allows for a user to wait for a license to become available.
 
Enabling License Queuing
If the user would like his license request to be put into a queue, he can tell RLM to wait for a license when all licenses are busy. RLM will automatically queue for a license at every license server that could potentially satisfy the request. When a license becomes available, the application will acquire it, and all the other queued license requests will be de-queued.  There are two aspects of this RLM queuing scenario that are better than previous license queuing methods. The first is that end-users, not vendors, control queuing with RLM. In other licensing systems, the license request must be marked as queue-able through that licensing API. So, unless the ISV enabled queuing from with the program, the end-user was unable to queue for licenses at all. The other unique element of the RLM queuing technique is that queuing requests occur at all license servers, not just at a single server or the first server in the list.  This means that users will get the first license available - enterprise-wide!
 
The RLM "EXPRESS LANE"
People may be familiar with the concept of the EXPRESS LANE from the local grocery store - you have a small number of items to purchase, and you don't want to wait behind someone who has many more items. So, the store provides a faster lane to speed you through.  RLM has a similar mechanism.  Let's say that all the licenses for a particular product that you want are in use.  There is someone ahead of you who is waiting in the queue for 10 licenses. You need only 1 license. When RLM's EXPRESS LANE is enabled,  you "jump" in front of the user who needs 10 licenses as soon as just one license becomes available. Without the EXPRESS LANE, you would have to first wait for a total of 10 licenses to be released before the user ahead of you received service, which would then allow you to get service when an additional single license became free. As with most RLM innovations, the EXPRESS LANE is enabled by the end-user, not dictated by the ISVs license software implementation.
 
License Queuing Priorities
Most large end users run software jobs with various levels of importance. To understand RLM's license queuing priorities, think of a hospital emergency room scenario where the hospital staff must make judgments about how and how quickly incoming patients should be treated. With RLM, software jobs that end-users assign with higher priority are processed before those with lower priority in the queue. This level of control enhances the value of the licenses by keeping them as busy as possible processing the most important or time-critical jobs ahead of those that can wait.

RLM Queuing Summary
End-users benefit from RLM's state-of-the-art queuing implementation in several ways. First, they enable and control queuing parameters, not the vendor. Next, RLM queuing is enabled across all the license pools, enterprise-wide. Also, RLM implements an EXPRESS LANE for users with fewer licenses to be services ahead of those that are waiting for more licenses. And, finally, RLM gives end-users a mechanism to assign relative priorities to their queued jobs so that the more important jobs are processed ahead of the others. Together, these enhancements make RLM stand above any other product of its kind.

Licensing Transition Strategies

With the advent of the Reprise License Manager (RLM) from Reprise Software, Inc., software vendors have been curious how to best migrate to RLM from older legacy license managers.

There are essentially two ways to make the transition; all at once, or gradually.

Strategy 1: Transitioning directly to RLM

If you decide to switch directly to RLM, then end users will find RLM very familiar, with concepts and procedures not too different from what they already know. RLM preserves the master/isv server components, as well as use of an end-user “options file,” similar key syntax and environment variables to control access to RLM license servers and to control various elements of RLM for the end user. 

In many ways, the transition is much like the process involved in upgrading to a newer release of an existing license manager—changes to the existing application binaries are needed, new servers and licenses need to be sent out.  Most software vendors have an established procedure for sending out their product with new releases of their existing license manager.  Consequently, the transition to a newer license manager like RLM can be managed using familiar processes and procedures.

Strategy 2: Use both LMs during the transition

If you choose to switch more gradually, then there are a couple different areas of focus. Remember that you need not immediately remove the legacy license manager.  Instead, a transition plan that introduces RLM to your customer base gradually may minimize the effort for both you and your customers. This technique allows you to transition your customer base over to RLM in phases, rather than all at once.

To begin, the most reasonable thing to do would be to have your application attempt to checkout a license from the RLM server.  If an RLM license is installed but not available for a very specific set of reasons (based on the checkout error status), then a message can be displayed to indicate the status (in use, queued, etc.). Otherwise, a secondary license request to the legacy license manager can then be tried. In this way, the application with both RLM and the legacy license manager would behave much as it does today in the event that an RLM license isn't available.

RLM prevents potential license doubling

During the transition phase, concern may exist about the possibility of issuing licenses that effectively duplicate an existing customer’s installed base—the licenses for the legacy license manager plus the licenses for the RLM-based products.  RLM can prevent this because it can use the same lock-file for legacy license managers as it does for itself, thus ensuring that only a single license manager can serve licenses on that host at any given time. In the case that the RLM server is started first, only the products served by RLM will have licenses available.  Software vendors and their customers can work together to partition certain servers and make the new, RLM-licensed products available from them, while existing legacy licenses either expire or are verified to no longer of use. 

Whichever way you choose to go, Reprise can work jointly with you and your customers to ensure a smooth transition to RLM.

For more general information about Reprise Software, Inc. or the Reprise License Manager (RLM), please contact us at info@reprisesoftware.com.