问题
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...
回答1:
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.
From e-nor:
These visitors have been active in the last 5 minutes, any one not active for over 5 minutes is dropped.
回答2:
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