Message rates are not displayed for amq.rabbitmq.trace exchange in Web UI

[Andrew Babichev]

When I publish a message to any exchange, message rates section of `amq.rabbitmq.trace` exchange page always displays `Currently idle`.

• RabbitMQ: 3.7.2
  
• Erlang: 20.1.7
  
• OS: MacOS High Sierra 10.13.4
  
• Browser: Google Chrome 65.0.3325.181 (Official Build)
  
• Management UI page: http://localhost:15672/#/exchanges/%2F/amq.rabbitmq.trace
  
• curl http://localhost:15672/#/exchanges/%2F/amq.rabbitmq.trace
  

[Michael Klishin]

The reason for that is that tracing does not use a standard way of publishing to exchanges

(even though amq.rabbitmq.trace is just a regular topic exchange).

RabbitMQ nodes already compute total rates so I see little value in collecting them for amq.rabbitmq.trace. It would

be a potentially confusing metric since tracing is selectively enabled for individual vhosts.