EmberJS, how to monitoring pending AJAX requests

I would like to inform to the User when there is a pending request on going.

The first idea is to display a spinner when there is some pending request, but also would be a nice idea to have the total number of pending requests so I can get to the User a more accurate information.

Is there any place in Ember where I can find this information?, I was checking into the Models but this took me to a nightmare. Also I don't find any thing in the DS.Store.