The size of Amazon’s cloud

According to a recent article from The Economist, it is estimated that Amazon are adding 90,000 virtual machines to their cloud every day.

That is a staggering number and (as the article notes) suggests that Amazon’s cloud is a bigger business than previously though.

The second cool thing in the article is the description of how the estimate was made. The “serial numbers” of the virtual machines were decrypted allowing for an accurate estimate to be made (I assume the serial number contains some sort of incrementing number). As is also noted in the article, this technique was similar to how the allies estimated the number of German tanks in existence in World War 2. This information was required to determine the feasibility of the Normandy landings – too many tanks would have made the landings a no-go. Relying on remorseless German efficiency and process, the allies used the serial numbers of captured German tanks to guess how many of them were being produced per month. The allies estimated 256, German records discovered later showed it to be 255.