How do EventMachine & Rails integrate?
I've found plenty of articles showing me what EventMachine is and how to set up endless "Hello World!" examples, but I'm still at a loss as to how this integrates with my Rails application.
As a example, I have an existing Rails app that has many concurrent users who may be editing the same row in my database simultaneously. I was thinking that I would allow the record to be loaded by two (or more) different people, but notify those users if the record was updated and force the latter users to reconcile any conflicting changes before saving it back to the database. I was thinking I could handle the notifications and reconciliations using Javascript on the client side and websockets (or flashsockets) to communicate with the browser (on the event that another user updates the record--like a push notification, or something).
The last part led me to EventMachine, but--as my lead-off question indicates--I'm at a loss about how to integrate this into my Rails app.
Can anyone give me some insight to this (like, a good macro-level viewpoint) or point me towards some good resources? (Apart from EventMachine's wiki, as I've already been there).
Answer
I spent a considerable amount of time looking into this. EventMachine needs to run as a thread in your rails install (unless you are using Thin,) and there are some special considerations for Passenger. I wrote our implementation up here: http://www.hiringthing.com/2011/11/04/eventmachine-with-rails.html