Sun Java System Access Manager Policy Agent 2.2 Guide for IBM WebSphere Portal Server

Configurable Policy Evaluation Mechanism in J2EE Agents

Starting with this release, J2EE agents can be configured to use two different mechanisms to remotely evaluate policies as follows:

Benefit - Configurable Policy Evaluation Mechanism: The configurable policy evaluation mechanism has a variety of benefits depending on the situation. The very fact that you can configure the policy evaluation mechanism is beneficial in that it enables you to choose the mechanism that best fits your site's requirements. Moreover, each mechanism has its advantages and disadvantages.

When configured to perform policy evaluation for all resources within an agent’s scope of protection the first request is, by design, time consuming while subsequent requests are faster since the results get cached locally by the agent.

For the second mechanism, the first request is no slower or faster than subsequent requests. All requests are processed relatively quickly. However, this mechanism increases network communication between the agent and Access Manager. Furthermore, the two mechanism can produce different types of cache growth in agent memory and thus must be evaluated closely to select the best option for your site's deployment. Key factors that could affect such a decision include the number of possible distinct resources and the number of policies applicable to an average user.