require 'fluent/plugin/output'
​
module Fluent::Plugin
  class RelabelOutput < Output
    Fluent::Plugin.register_output('relabel', self)
    helpers :event_emitter
​
    def multi_workers_ready?
      true
    end
​
    def process(tag, es)
      router.emit_stream(tag, es)
    end
  end
end

# emit event
router.emit(tag, time, record)
​
# emit event stream
router.emit_stream(tag, es)
​
# emit error event
begin
  # do something
rescue => error
  # Route event to @ERROR label or
  # log error message when @ERROR label is not defined in configuration
  router.emit_error_event(tag, time, record, error)
end