Discord's Growth and DDoS Mitigation with Cloudflare

As Discord prepared for rapid growth, they needed a way to affordably and quickly scale their existing hardware infrastructure, while maintaining performance and security. Performance wise, Discord would need to transition from serving their content from a single homed server to a high performing CDN (Content Delivery Network) partner that could serve their static assets from all around the globe. Security wise, Discord needed to protect their websockets-based traffic from the rampant DDoS attacks that they were experiencing. As CTO Stanislav Vishnevskiy explained, “Since we are a gamer focused product we attract a lot of users who love to DDoS each other during game matches. As we grew more popular the intensity and occurrences of these DDoS attacks increased to the point where our engineers were constantly dealing with them.” Vishnevskiy continued, “Before Cloudflare, we were using a large number of HAProxy boxes with DNS load balancing to be able to failover during DDoS attacks on our real-time gateways.” However, their initial hardware solution could cost Discord up to six figures annually at scale and would still require work from Discord’s engineers.

Discord is a voice and text communication app for online computer gamers. Discord’s goal is to become the de-facto standard communication app for PC gamers, and they’ve seen success, boasting 2.4 million concurrent users and over 25 million registrations as of July 2016. As Discord prepared for rapid growth, they needed a way to affordably and quickly scale their existing hardware infrastructure, while maintaining performance and security. They needed to transition from serving their content from a single homed server to a high performing CDN (Content Delivery Network) partner that could serve their static assets from all around the globe. They also needed to protect their websockets-based traffic from the rampant DDoS attacks that they were experiencing.