How does the Firefox website create a download statistics page?

Looking at the country_report.json response in the firebug Net tab, you can see something like this for each country:

{"total": 95843579, "RPS": [5,6,6,7,4,9,12,9,3,10,6,8,8,7,5,10,8,4,12, 8,10,10,7,4,9,13,9,4,9,13,7,7,6,18,10,7,9,5,3,6,5,11,9,5, 6,9,7,2,8,9,11,5,10,7,5,6,11,7,7,2], "count": 455, "name": "United States", "code ":" USA "}

Thus, these charts are not updated every second in real time. Instead, they build a recent request history, one point per second, and periodically request a new dataset to build.

They seem to be using something called SQLstream on their end to collect this data.