Slow action in Rails application: ActionDispatch::Routing::RouteSet#call

Question

According to NewRelic the slowest transaction in my application is:

Middleware/Rack/ActionDispatch::Routing::RouteSet#call

It takes

Answer 1

If by any chance you are using the "Treat" gem, remove it. Seems like a bug.

https://github.com/louismullie/treat/issues/84

Answer 2

In my case, I was using rocket_pants. Its controllers don't inherit from ActionController::Base so it was showing up in newrelic as middleware. https://discuss.newrelic.com/t/middleware-call-shown-as-web-transaction/25861/8