[overlord-issues] [JBoss JIRA] (RTGOV-66) Synchronous activity event processing

Synchronous activity event processing ------------------------------------- Key: RTGOV-66 URL: https://issues.jboss.org/browse/RTGOV-66 Project: RTGov (Run Time Governance) Issue Type: Feature Request Reporter: Gary Brown Assignee: Gary Brown Fix For: 1.0.0.M5 The current policy enforcement example has two parts, the event evaluation using mvel to determine whether a customer should be suspended, and then an exchange handler configured in switchyard app to enforce the decision. This is an asynchronous approach to enforcement that potential enables a customer to exceed their restrictions (albeit briefly) before the enforcement kicks in. In situations where enforcement must apply immediately a policy has been broken, then we need a synchronous event evaluation to occur at the activity collector and potentially immediately affect the message exchange. Need to consider: - whether this mechanism should use a restricted form of the EPN as a way to make configuration consistent - although it would be dealing with derived ActivityType rather than an ActivityUnit at the top level, and interaction between nodes would also be synchronous, which may lead to ordering issues or configurations that would not be supported. - what actions are required based on the decision made in a policy - for the customer suspended case it is likely to be just throwing an exception, but are there other actions? Deployment of these sync policies should be equivalent to other components in the architecture. Benefit of having a specific mechanism may be that it doesn't cause confusion with the full blown configuration, and also the fact that it is supposed to be returning a decision, rather than just propagating derived results. Not using the EPN may have benefits of not including its mechanics in the lightweight server configuration. However we need to consider how it would interact with 'services' (e.g. cache) - possibly this could be a similar/same mechanism without having to use the whole EPN infrastructure.