On several customer deployments, I’ve seen lots of customizations through Scripts or Drools that expect alarms instead of events. The problem is that the current daemons are triggered by events, which makes the workflow harder if you are interested on alarms, as it might be a slight delay when an alarm is created and associated with an existing event.
For this reason the Northbounder interface was created. Unfortunately there is no way to execute custom code or perform business logic when an alarm is created. The idea is implement a Drools NBI, and Script NBI so we can trigger custom logic associated with NorthboundAlarm instead of Event.
The usage would be very similar to the current ones. One difference is that the Drools NBI won’t implement timers as this is a bad practice. If someone needs time based rules then Drools Fusion (or CEP) should be used on the rules. That facilitates the reload operation, assuming the working memory can be restored, which depends on the changes performed on the rules.