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Tips for Multi-Server Site Configurations

Multiple Independent License Servers

A site may have multiple RLM license servers serving the same licenses, either in a failover scenario or when the site has decided to split its complement of licenses for a given product across multiple servers. The licensed applications need to know which hostnames and port numbers the license servers are on. There are several ways in which this can be done:

The licensed application may provide a configuration utility which allows the user to configure multiple license servers.

The environment variables RLM_LICENSE and <isv>_LICENSE may be set to a list of port@host values, for example:

  • set RLM_LICENSE=5053@server1;5053@server2;5053@server3
  • export reprise_LICENSE=5053@london:2234@newyork:12343@tokyo

Note that the separator character is semicolon on Windows and colon on UNIX.

A separate license file can be configured to reference each license server. Each license file need only contain a SERVER line with the appropriate host name and port number – the hostid field is ignored by RLM on the client side.

Example:

License File 1:

  • SERVER london any 5053

License File 2:

  • SERVER newyork any 2234

License File 3:

  • SERVER tokyo any 12343
Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website

Modifying Licenses in the Field

Using “REPLACE =” and “UPGRADE”

Probably the most basic of all licensing policy methodologies is the ability to control the duration of the license with an expiration date in the license. At times, as in demo or trial modes, you may want your licenses to have a short duration, 30 days or so. Still other times, you may sell usage rights on a periodic basis, monthly or annually, requiring a new license to be issued upon renewal.

In many cases however, you want your licenses to be perpetual, with no expiration date. What happens if over time you want to do a radical overhaul of your license policies or you have negotiated a new contract with a customer that requires issuing of new licenses that would replace the existing licenses? Perhaps you issued licenses that were only good for a defined version of your product and now you are upgrading to a newer version. The permanent licenses do not expire so how do you make the necessary changes?

Replacement and Upgrade Licenses to the Rescue
The way to render ineffective one or more licenses which you have already issued is to use the REPLACE[=product-list] option in the new license. REPLACE= causes RLM to ignore the “replaced” or old RLM license(s).

Upgrading licenses to a new version. There are a couple approaches you can take if you are upgrading existing licenses that are valid for a previous version of your software to a new version release. If you are upgrading all instances of the existing licenses to a new version then the REPLACE= option works very effectively.

But, what if you want to upgrade only a subset of the existing licenses to the new version and leave the rest unchanged? The UPGRADE license type was created for this very situation. Using a an UPGRADE license type, you can upgrade a limited number of the existing licenses to a newer version and the remaining licenses will run under the older version. UPGRADE does not grant any new license rights, it only upgrades the specified number of existing licenses to a new version.

“UPGRADE” and “REPLACE=” are specified in the license file, external to the application, with no modification to the source code being necessary.

Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website

Licensing by Longitude

Can you gain by restricting your software licenses to certain regions of the globe?

Independent software vendors (ISVs) are often reminded of how interconnected their customers are. For instance, they may receive a support call from someone in India using a license on a server in Indiana.

Depending on the ISV, this may not be the original intent of the license. For a variety of reasons, some some them wish to restrict usage to the location into which the license is sold.

Why restrict by location?

The primary reason to restrict licenses to certain geographies is to try to maintain price discipline across territories and to provide lower price points for more tightly bound licenses. For instance, ISVs who sell to large multi-national customers may want to encourage regional use of licenses with lower per-seat prices, and charge a premium for licenses that span the globe. Also, ISVs who sell through a reseller channel may want licenses to be deployed locally in order to avoid unproductive price competition between regions.

Creating Geo-Aware Licenses

With the Reprise License Manager (RLM), licenses can be generated to restrict the timezones within which the licenses can be used. The mechanism is relatively straightforward. Simply add the keyword TIMEZONE=timezone-spec to any license.

The value assigned to the TIMEZONE keyword is a bitmap representing the client’s time zones, relative to GMT, within which the licenses are valid. In other words, it allows the specification of a set of valid timezones for the client machine that performs the license checkout. The timezone-spec is a 24-bit HEX number, with one bit set for each timezone you wish to be valid. Bit 0 represents GMT and each bit to the “left” of bit 0 represents one timezone (one hour) west of GMT. Thus bit 5 would be EST, bit 8 would be PST, bit 23 would be one hour east of GMT, and so on.

TIMEZONE Keyword Examples:

North America (GMT-5 through GMT-8): 0000 0000 0000 0001 1110 0000, TIMEZONE=1E0

Europe (GMT-0 through GMT+2): 1100 0000 0000 0000 0000 0001, TIMEZONE=c000001

Japan (GMT+9): 0000 0000 1000 0000 0000 0000, TIMEZONE=8000

Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website

Hold on to that License

Using RLM keywords “HOLD=” and “MIN_CHECKOUT=”

Many valuable software tools that require floating licensing run for only a short time.  These include various solvers, development and design tools, and other specialty software products that are designed to perform very specific tasks very quickly.  Unlike typical interactive or desktop applications, these short-burst applications typically do not have a GUI of there own, and are often launched by other applications within a product suite.

The “Short Duration” Licensing Challenge
The licensing challenge for these applications is based on the fact that a floating license is a shared license.  When a floating license is used it is unavailable until it is returned.  But, short duration tools consume licenses for only a short time, so a single license could potentially be shared by a large number of users.

The “Short Duration” Pricing Challenge
The licensing challenge is really a pricing challenge.  In other words, how do you set a price for a single floating license that is low enough for small sites to afford while at the same time scaling your pricing so that larger sites that use more of your software pay you more for that use?  How do you prevent large sites from satisfying their requirements by licensing only a single floating copy of your software?

Extra Hold Time: HOLD=
One way to handle this problem is to implement an extra “hold time” on the floating license.  This instructs the license servers to hold the license for an extra number of seconds after it is released by the client, regardless of how long the license was actually used.  So, for example, if the application uses the license for 20 seconds, upon termination of the program the license is “held” for an additional 300 seconds, say, for a total of 320 seconds.  The effect is that the floating license can be shared by fewer users because it is “held” this extra amount of  time each time it is used.  This encourages customers to order more licenses to satisfy their user population.  But, some customers may object to the license being unavailable for such a long time.

Minimum Checkout Time: MIN_CHECKOUT=
Another similar method is to enforce a “minimum” license checkout duration.  Instead of extra time being added to the end of a licensing session as in the above example, a license would be held for at least a specified minimum amount of time.  So, a license with the minimum checkout time set to 300 seconds would add 280 extra seconds to a license that was in use for only 20 seconds.  Licenses used for more than 300 seconds would not be affected.

Both “extra hold time” (HOLD=) and “minimum checkout time” (MIN_CHECKOUT=) keywords are specified in the license file, external to the application, so that the same executable can use either method without modification to the source code.

Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website

Queuing for Licenses

Adding support for license queuing promotes more efficient use of a user’s inventory of licenses

The RLM license server has the ability to manage a queue of requests for a license when all licenses are in use. If queued for a license, the application is notified by the license server when a license has become available. Queuing occurs in the course of a normal checkout if the application’s environment specifies a value for the variable RLM_QUEUE.

Applications must be made aware of Queuing

The licensed application needs to support queuing, in that it has to react appropriately to the RLM_EL_INQUEUE error status after a checkout attempt, instead of treating it as a hard error. The application should keep checking the license status periodically as long as the user wishes to remain queued for the license. Not all RLM-licensed applications do this, but most do.

Queuing to Multiple Servers is Transparent

The licensed application side of RLM manages queuing in a multiple license server environment transparently. If all licenses are in use on all of the license servers that the licensed application is aware of, RLM will queue for a license on all of the license servers. As soon as a license becomes available on one of the servers, it is granted to the queued application, the application dequeues on the other servers. This is handled transparently to the application, in the RLM library. [ Don’t you wish supermarket check-out lines worked this way? You’d be waiting in all of the lines at once. ]

All Aboard the Express

RLM has the concept of “express” license pools for the purposes of queuing. An express license pool is one where queuing is not on a strictly first-in first-out basis. This is best illustrated by example. Consider a pool of 10 licenses: 8 are currently in use, and 2 are available. Application A requests a checkout of 3 licenses, and specifies that it wants to queue if the request can’t be granted immediately. Its request is queued because only 2 licenses are available. Application B then requests 2 licenses. If the pool is an express pool, Application B’s request is granted immediately. In a non-express pool, Application B’s request would be queued behind Application A’s request. By default, all pools are express pools. This can be changed by the end user on a pool by pool basis, or globally, via the EXPRESS directive in the ISV options file.

Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website

SketchList Selects the Reprise License Manager (RLM)

Summary: Here at SketchList Inc. we use RLM for four primary reasons. First, it protects our investment in our software by assuring us that only paying users can use our software. Second, it provides us with flexibility in our pricing plans by allowing us to time limit keys we sell to our customers. Third, the RLM software and services are high quality and professional in nature. And finally the RLM pricing and scheme provide fair value to our company.

Licensing Challenge: To develop a scheme that allows us to sell online, offer trials, provide many pricing options, and address both the PC and MAC computer users with a minimum of operational burden.

Why RLM: While the consultants charged with recommending the solution had originally selected another package, the pricing for that package / service was too high and inflexible. After RLM was introduced to the consultants they tested it, incorporated it into the SketchList product, and have since recommended it to other clients of theirs. We were able to introduce RLM to our environment and test it to our satisfaction within the trial period. We are currently using it to provide keys for a new release that is in beta, and have seen no problems.

About SketchList Inc: SketchList 3D is a software product that helps professional woodworkers prepare winning bids for new projects and customers. It allows woodworkers to use virtual 3D objects – boards, doors, drawer and hardware – to quickly and easily design and demonstrate their proposed work to prospects. Photo-like quality images in 3D help their prospects see what they are buying. In addition, all drawings and reports necessary for building the project are being created as designs are developed.

Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website

Infochem Computer Services Ltd. Licenses the Reprise License Manager (RLM)

Infochem converted their robust FORTRAN application from dongle-based licensing to a file-based system using RLM, reducing support costs while increasing customer satisfaction.  According to Dr. Richard Szczepanski, Director, “We have always regarded a licensing system as an essential part of our software. We started using a dongle-based system in the early 1990s and this has developed over the years stand-alone installations to network licenses. Dongles are not always popular with customers but they do an effective job of controlling licenses.”

“We chose RLM to enable a complete electronic delivery of the software product and license. In the past we have considered a number of license-file based systems but poor experiences as users of these systems and high costs prevented us from adopting them for our own software.”

“It is simple to sum up our experience with Reprise and RLM: we are happy and our customers are happy.”

About InfoChem:

Infochem is a specialist engineering company that provides thermodynamic modeling software and consultancy services to the oil & gas, process and chemical industries. We have been established for over twenty years. Our principal software product, Multiflash, is a powerful and versatile program for modeling physical properties and phase equilibria involving any number of fluid and solid phases. It is used by engineers worldwide, either as a stand-alone program or in conjunction with other software. Typical applications include flow assurance and life-of-field studies for the oil industry, pipeline network modeling and process design and optimisation. A complementary product, FloWax, simulates the deposition of wax from oils and condensates in multiphase pipelines.

We have always regarded a licensing system as an essential part of our software. We started using a dongle-based system in the early 1990s and this has developed over the years from parallel port dongles to USB dongles and from stand-alone installations to network licenses. Dongles are not always popular with customers but they do an effective job of controlling licenses.

It is a common complaint among software suppliers that the licensing system consumes an uncomfortably-high proportion of support effort. It has certainly been our experience over many years. This was one of the main reasons for investigating alternative license control systems. Another was to enable a complete electronic delivery of the software product and license. In the past we have considered a number of license-file based systems but poor experiences as users of these systems and high costs decided us against adopting them for our own software. We were aware of RLM for some time before we decided to try an evaluation. We talked to other users and their positive comments convinced us to go ahead.

Our software is written in Fortran so we needed some help to get to grips with the API. Reprise put us in touch with another Fortran user and that made the task simpler. Overall our experience was good. The product performed well and met our requirements. Our software comes as a basic product plus a number of optional modules; we provide node-locked and floating licenses and we issue short-term evaluation licenses. All this is well-supported by RLM. In particular, the cost and effort of providing evaluation licenses has decreased dramatically because there is no hardware device to deal with. The process is smoother, faster and simpler for prospective customers.

The transition to RLM has been transparent to our customers because we are using the dongle system and RLM in parallel. We have a single program that incorporates both licensing libraries. New licenses are RLM-based and, although it is still early-days, the support effort has indeed decreased. Most importantly, we have not been faced with any of the long trouble-shooting investigations that were sometimes necessary in the past. We are still learning but the effort has been worthwhile.

Help for RLM license administration

- view the RLM License Administration Manual here
- Visit our license administration help page here

Written by Reprise Software - Visit Website