Web page that clicking 'start' will perform Ajax requests one after the other (sequentially), update on the progress on screen at the end submit all results (which operation succeeded and which failed) via Ajax.
The requests can be user_index (0 to 100) and the response tells whether he is online or not. Make the server side to return random 50/50% to be online or not.
git clone https://github.com/sk91/promise-test.git
cd promise-test
npm start
Open http://localhost:3000 in the browser