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Once validated and corrected for any conflicts, the policies are placed in an appropriate repository, and are made available to the other subsystems and components that might make use of them. In addition, the decisions and actions taken by the policy are distributed. Distribution occurs either in conjunction with the distribution of recipes (if for example they are related to service instantiation) or independently, if the policy is unrelated to a particular service. With this methodology, policies will already be available when needed by a component, minimizing real-time requests to a central policy engine or PDP (Policy Decision Point). This improves scalability and reduces latency.
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Policy Distribution
After a policy has been initially created or an existing policy has been modified, the Policy Distribution Framework sends the policy from the repository to its points of use, before it is actually needed. This distribution is precisely targeted so that each distributed policy-enabled function automatically receives only the specific policies that match its needs and scope.
Notifications or events can be used to communicate links/URLs for policies to the components needing policiesthat need them, so that components can utilize those links to fetch particular policies or groups of policies as needed. Components in some cases may also publish events indicating they need new policies, eliciting a response with updated links/URLs. Also, in some cases policies can be given to components indicating they should subscribe to one or more policies, so that they receive updates to those policies automatically as they become available.
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