| Name | Description |
|---|---|
| ID | Publish-Event |
| Brief Description | The Even Handler is tasked to deliver Event to all relevant Subscribers |
| Primary Actors | Publisher, Event Handler, Subscribers |
| Preconditions | - Subscriber has to be subscribed with a filter of matching event type, date, and metadata. - Subscriber has to be an authorized consumer of the publisher system. - Publisher has to be registered as a System. - Publisher has to be a provider of at least one service, registered in the ServiceRegistry. |
| Main Flow | - The Publisher sends an event to the Event Handler. - The Event Handler validate: - - the request format - - the Event source - - the Event TimeStamp. - The Event Handler select all Subscribers by the type of the event - The Event Handler filters Subscribers by authorization. - The Event Handler filters Subscribers by timestamp. - The Event Handler filters Subscribers by metadata. - The Event Handler put the event with the filtered subscribers list into the publishing queue. - The Event Handler returns "ok" to publisher. - PublishingQueueWatcherTask senses new item in the publishing queue. - PublishingQueueWatcherTask, based on the number of subscribers, pass the event with the filtered subscriber list either to the expressExecutor ( which has a thread pool initialized at startup time ) or creates a new publishRequestExecutor (with its own thread pool ). - The used Executor, for each Subscriber, execute the PublishEventTask, where it removes the publisher from the event and send the result to the subscriber. |