I'm wondering how Google Analytics Real Time user interface works, what's the technique ? Do they use long-polling from the client to keep the UI statistics instantly up to date by delivering realtime information from the server to the client? I just open Chrome dev tool on network tab and there is a infinite request on https://www.google.com/analytics/realtime/bind Does anybody know the trick? It works flawless...
The below refers to how the real time data is collected, not how the UI updates. (It looks like the UI is just using AJAX polling on the client-side, though)
No special polling or client-side technique is used. Data collection is the same as it always has been.
Instead, Google Analytics will assume that someone who's triggered a pageview in the last 5 minutes is still an "active" visitor.
These visitors have been active in the last 5 minutes, any one not active for over 5 minutes is dropped.
I was one of two people who built the first version of the Realtime Analytics UI. We used Closure's BrowserChannel.
来源：https://stackoverflow.com/questions/8330780/how-does-google-analytics-real-time-work