Type:
Class
ActiveSupport::Subscriber is an object set to consume ActiveSupport::Notifications. The subscriber dispatches notifications to a registered object based on its given namespace.
An example would be Active Record subscriber responsible for collecting statistics about queries:
1 2 3 4 5 6 7 | module ActiveRecord class StatsSubscriber < ActiveSupport::Subscriber def sql(event) Statsd.timing("sql.#{event.payload[:name]}", event.duration) end endend |
And it's finally registered as:
1 | ActiveRecord::StatsSubscriber.attach_to :active_record |
Since we need to know all instance methods before attaching the log subscriber, the line above should be called after your subscriber definition.
After configured, whenever a “sql.active_record” notification is published,
it will properly dispatch the event (ActiveSupport::Notifications::Event)
to the sql method.