Intelligent DNS Based Load Balancing at Dropbox

Intelligent DNS based load balancing at Dropbox

The Dropbox Traffic team is charged with innovating our application networking stack to improve the experience for every one of our users—over half a billion of them. This article describes our work with NS1 to optimize our intelligent DNS-based global load balancing for corner cases that we uncovered while improving our point of presence (PoP) selection automation for our edge network. By co-developing the platform capabilities with NS1 to handle these outliers, we deliver positive Dropbox experiences to more users, more consistently.

In our previous post about the Dropbox edge network, we were talking about geolocation-based load balancing. The idea behind this approach could be simply described as sending the user to our closest point of presence. Let’s try to decipher this statement: being sent in this context means that when a user is doing DNS request, we would reply with a specific Dropbox IP address.

For different users, we reply with different IP addresses. With geolocation-based load balancing, the “closest” PoP is indeed the one which is closest in terms of distance from the user. In the picture below you can see how users are mapped to our edge PoPs.