Finding the closest data center using GeoIP and indexing

In production, we use GeoIP to determine the country/state of the server in question, and then perform a lookup in the generated indexes to determine the preferred region. I say preferred (and not closest) because the indexes are static, and are not calculated on the fly. This was a design decision to allow us to tweak the indexes with the help of community feedback.

The location based calculation described was used to generate the baseline indexes to provide a relatively good starting point. One of the reasons for writing this blog post and publishing the indexes, was to take us to the next phase of tweaking the indexes, hence the closing paragraph:

"we need your help to tweak the indexes - as you have better knowledge and experience on your connection latency and speed. Please let us know if you think we should associate your country/state to a different Amazon region."

The countries and US indexes consist of 249 and 62 entries, respectively. We don't have the resources to perform latency testing in each and every location, for that we need the communities help.