ActiveSupport::Notifications

Rails3からこんなのあったんだ ActiveSupport::Notifications - APIdock

In the example above “render” is the name of the event, and the rest is called the payload . The payload is a mechanism that allows instrumenters to pass extra information to subscribers. Payloads consist of a hash whose contents are arbitrary and generally depend on the event.

Full article: http://apidock.com/rails/ActiveSupport/Notifications