new.png Jazz licensing explained

Authors: MichaelTabb
Build basis: The Rational solution for Collaborative Lifecycle Management (CLM), releases of version 4.0

This topic covers how the Jazz licensing subsytem works. It explains the various license types that the server supports as well as some interesting features that may impact users and admins alike.

User roles and client access licenses

Each user is assigned roles based on team and/or project membership. For example, there could be roles to read/write work items, perform source code management (SCM) operations, etc. Each one of these roles is mapped to an operation ID that is defined in a client access license (CAL). If the user has the role, it does not mean they can perform that action yet. The user must be assigned a CAL in order to enable the role. There are 3 types of licenses that the Jazz server supports:

  1. Permanant or authorized
  2. Floating
  3. Token

Capabilities

Licenses are designed to allow for overlapping capabilites while maintaining an exlcusive set of its own capabilities. For example, a Rational Team Concert (RTC) Developer license may provide SCM capabilities as well as some work item read/write access. Meanwhile, a Rational Quality Manager (RQM) Test Professional license may provide some test case authoring capabilities as well as some work item read/write access. There is an intersection between the two licenses at the work item read and write access. If a user was performing a work item read operation, either of these licenses could be used to satisfy the assertion request. The following figure illustrates the overlapping capabilities of some sample product licenses:

Overlapping.png

Some licenses are perfect subsets of each other. This means that one license contains exactly the same operations as another and additionally unlocks some other capabilities. An example of this is the Rational Team Concert (RTC) Developer license. The Developer license contains exactly the same operations as the Rational Team Concert (RTC) Contributor license, but also provides additional capabilities. For this reason, the Contributor license is considered a perfect subset of the Developer license.

Subset.png

License assertion

A license assertion is a check by the client to make sure a user has a license to perform an operation. Different actions a user performs in an application may result in the checking of a license for that action. That action gets translated to an operation ID, as defined above. All licensing assertions occur on Jazz Team Server (JTS). Starting in version 3.0, the applications receive a license check from their clients, but actually sends the assertion request to Jazz Team Server. All license management is done on Jazz Team Server. In the illustration below, a user may be performing an SCM action. That action will require the user to have a license, so the following steps occur for a license assertion:

  1. The user on a Rational Team Concert client performs an SCM action. The Rational Team Concert client code requires a license for the action. It makes a call to the server to perform the check
  2. The license service on the server handles this request, and performs the check. If the check fails, a LicenseNotGrantedException is thrown, and the client receives the error and is responsible for propogating it to the user.

Simple-license-flow.png

Permanent or authorized licenses

If assigned, a user will always have this license to perform the operations that are unlocked by it. The only way a user will not be able to use this license is if it unassigned.

Floating licenses

The floating license requires an additional step on top of the simple license flow. It is slightly more complicated and involves a couple of different pieces. A floating license requires that the license be checked out. Unlike a permanent CAL, the user does not actually own the license. A floating license can be assigned to n-number of users. The pool of licenses available is generally less than the number that can be assigned.

Floating license server

Floating licenses are managed by a floating license server. The server can actually be Jazz Team Server itself, or it can be a freestanding server that Jazz Team Server points to. The floating license server contains a pool of licenses, by type, that constantly changes depending on the server usage. There is a difference between a license assignment and a license checkout. An assignment is nothing more than a record which is persisted that associates a license to a user. This does not guarantee a license will be available when the user attempts to use the product. A checkout occurs when the user which has an assignment goes to actually use the product in a way that a license is required to perform an operation. At that point, the license then needs to be checked out from the license pool.

Checkout selection

Often a user has more than one floating license assigned to them. When an operation is asserted by a client, that operation may be able to be satisfied by more than one of the licenses assigned. This forces Jazz Team Server to decide which license gets checked out. When there is more than one, the license service sorts the list using the following algorithm:

  1. Permanent CALs
  2. Existing floating license checkouts (version 4.0.3: non-token first, then token)
  3. Subset first
  4. Arbitrary

The list is compiled with all of the licenses in the list will be able to satisfy the operation being asserted. Note: The list may contain permanent CALs.

Assertion-sort.png

A breakdown of the ranking:

Permanent CALs

A user always has a permanent CAL assigned. No checkout is required. Floating is limited, and on a shared basis. Using floating over permanent reduces the amount available for everyone else.

Existing floating license checkouts

If the user already has a checkout, use the existing lease; otherwise, another license has the potential to be checked out. Because of their associated cost, token licenses are considered after "normal" floating licenses.

Subset first

Floating licenses that are perfect subsets, or the most restrictive licenses are used first before their more costly superset parents. For example, the Rational Team Concert (RTC) Contributor license is a perfect subset of the Rational Team Concert (RTC) Developer license. If the user has both assigned, the Contributor license will come first in the list.

Arbitrary

Licenses that have mutually exclusive operations and have no subset licenses available are the last to be selected. For example, this would happen if you have a Rational Team Concert Developer and a Requirements Management (RM) Analyst CAL assigned.

Checkout flow

After the license are sorted and it is determined that the license to use is a floating license, the checkout process begins. The following outline shows a flow from the license service that needs to check out a floating license:

  1. The license service selects the license (floating, in this example) needed to satisfy the assertion request
  2. The license service uses its floating license client to determine how to get a lease from the floating license server. It does the following actions:
    1. If the client has a reference to a lease for the license being checked out, it is placed on an asynch refresh queue, which runs peridocally to increase the lease timeout on the floating license server
    2. Otherwise, the client sends a checkout request to the server, and if successful, caches the lease information.

Floating-license-flow.png

Floating leases

When a license is successfully checked out from the available pool, a lease record is persisted in the database which resides on the floating license server. The lease contains some bits of information such as user, license, and lease expiration time. With the lease persisted, in the event of a server restart, the expiration time does not reset.

Token licenses

Token licenses are built on top of floating CALs. The only difference in their definition is that there is an associated token cost. The cost translates to the number of tokens to check out. If two otherwise equivalent (floating+token, supporting same operation) licenses are being considered for checkout, the one with the lesser token count will be selected. The checkout flow follows mostly the same flow as floating licenses do. After the floating license service realizes that a token checkout needs to occur, it delegates to the RCL token provider service, which in turn calls to the FlexLM server to perform this checkout. The tokens are not managed by Jazz, it is done so externally by a FlexLM solution that integrates into Jazz. After the tokens are checked out successfully, a lease is created and persisted in the same way that a floating lease is persisted. Here is an illustration of a token checkout:

Token-flow.png

Subset/superset assignment - version 4.0.1

In version 4.0.1, the restriction to disallow assignment of subset licenses was removed. Previously, as an example, a user could not have a Rational Team Concert Contributor and Rational Team Concert Developer assigned. These were looked at as 2 separate roles. This did not cover the case where a user had split roles and spent most of their time as a contributor and a small portion of their time as a developer. This would force a user to have the more costly developer license. Starting in version 4.0.1, the system provided more flexibility for this use case, and allowed the user to have both licenses assigned. There are some caveats, though. Note: This applies to floating licenses only.

  • When a user performs an action that can be done by both the Contributor and Developer, the most restrictive or subset license is checked out. In this case, the Contributor would be used.
  • If the user performs an action that requires a Developer license and currently holds a Contributor license, both licenses are checked out and held onto until:
    1. The user logs out
    2. The lease expires due to inactivity

The rationale behind this is that users should only perform actions defined by their assigned license(s) for their role(s). In other words, if a person ever performs Developer actions, that person needs to be assigned Developer license, not a Contributor license.

Compatible license behavior - version 4.0

In version 4.0, a new concept to enforce compatiability between applications and licenses was introduced. Jazz needed a way to prevent licenses from a previous version of a product to work with a newer version of a product. To accomplish this, an application can optionally declare a compatible license version in its SCR document. Meanwhile, the CAL must also declare what product versions it is compatible with. This check is performed at run time when compiling a list of available licenses to use upon a license assertion. A license is considered valid if the application that is sending the request to assert is in the list of compatible behaviors in the CAL. The figure below is an illustration of the pieces that make up the license compatibility feature:

License-compatibility.png

Related topics: Deployment planning and design

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Additional contributors: None

This topic: Deployment > WebHome > DeploymentPlanningAndDesign > JazzLicensingExplained
History: r26 - 2013-09-25 - 19:23:40 - Main.alexberns
 
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