Notification

Notifications

Notification is how changes in one domain / system / application are communicated out to (and therefore acted upon by) other domains / systems / applications.

In this system there are two types of thing that we can raise notifications about : a new entity is created and a new event is appended to the event stream of an existing entity.

Background

A notification only says "this happened" and doesn't say what should be done with the thing that has happened. For that reason I am not passing state information in the notification - it may be that you need state to be passed in the notification in which case i would recommend taking and extending this library.

A notification needs to indicate what it happened to. In this library that is done by the combination of Domain, Entity Type and Entity Instance Identifier.

For an event being appended to the event stream of an existing entity also needs to know the "as of" (when) of the event - which we send as the sequence number of the Event Stream

Technology

Notifications are sent via Azure Event Grid

Configuration