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Mapping AWS data centers for fastest connection

Yes, that's 'fastest', not closest.


A while back I published a blog post entitled Finding the closest data center using GeoIP and indexing, which described how we automatically determine the AWS regional data center to be used for storing encrypted server backups.

We used the same solution to determine the preferred region when launching cloud servers in the Hub, as well as selecting the closest APT package archive for all TurnKey deployments.

New and improved

Since the original publication, Amazon built new regional data centers in Oregon, Sao Paulo and Tokyo, so the indexes needed to be updated.

While adding support for the new regions I decided to take it a step further and add some improvements.

Improvement #1: Automatic association (distance)

The method originally used to perform automatic association of countries/states to data centers was lacking some what and needed to be improved.

We are now using the Haversine formula, which is used to determine great-circle distances between two points on a sphere from their longitudes and latitudes.



Improvement #2: Incorporated world wide underwater cables (latency)

Originally we relied on user feedback of connection latency to tweak the indexes. This didn't scale very well, so we needed a way to make it easier.

Based on Gregs Cable map, we could mashup the automatic associations and tweak the index overrides based on expected latency.

It turns out that this was a crucial part of the equasion, as a user might be physically closer to data center X, but in reality the connection to data center Y is faster. For example, previously Australia was allocated to Singapore but has been moved to California as the pipe is much fatter (see the visual map below).

Improvement #3: Open source

We originally published the indexes, but have now open sourced the whole project on github in hope that others might find it useful, and make collaboration easier.

Putting it all together

The below screenshot plots countries/states to their associated AWS regional data centers, and overlays the world wide underwater cables for reference:


Want to zoom in? Toggle active and future cables? Check out the live mashup.


Liraz Siri's picture

I agree that it would be better to just go ahead and measure latency and bandwidth directly. The trick is how do you do that from all over the world. Hmmm... maybe if the Hub doesn't already have your network's routing information it asks the appliance to run a few tests and measure latency directly, then caches that information for future reference.
Liraz Siri's picture

Good thing Alon open sourced the code. Now let's hope a global routing expert runs into it and decides it would be a fun way to spend some time off on the weekend.
Chris Musty's picture

Above comments aside, I actually had no idea Virginia would be faster than Singapore (I am in Sydney Australia). I have never had need to test for speed issues because Singapore is fast enough for the db frontend apps I am developing. If I can get it faster in Virginia - SWEET! The only issue with that is when the client asks "where is the cloud", sometimes they get turned off when you say "another country".

So as far as practical use goes it may help with data heavy apps in the future, at least for my company.

I am just about to start testing cloud servers and backups with my apps after spending months testing on site installations with TKL (which all came up trumps incidentally) so this information comes with good timing.

Thanks guys!

Chris Musty


Specialised Technologies

Chris Musty's picture

Just how I like my networking cheap and fast!

Chris Musty


Specialised Technologies

Alon Swartz's picture

Good catch Jack - thanks, it was a typo - should have been California. I've updated the blog post.

Alon Swartz's picture

Sure Eric, go ahead. All I ask is that you link back to the original article.

Jeremy Davis's picture

But seeing as AWS have added Frankfurt (which we are yet to support) it could not be considered up to date in that sense...


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