The traffic stack at LinkedIn acts as a bridge between the user device and LinkedIn Services. The aim is to provide a consistent user experience with the best possible latency for a wide spectrum of use cases. It also provides a platform for DDoS and anti-abuse defenses, authentication, security, and other common business logic applicable to all online/API traffic.
With millions of QPS, hundreds of clusters and thousands of servers to load balance, the stack needs to be highly efficient and scalable. Because of LinkedIn’s deployment infrastructure requirements, the stack needs to be highly dynamic and customizable as well.
The current stack is based on another open-source proxy with several LinkedIn customizations. In the last few years, our business along with our traffic requirements has been evolving fast. At the same time, the HTTP stack has also evolved, and we are also exploring the move to the cloud. These rapid changes in the ecosystem forced us to revisit our stack, which was built several years ago.
In this talk, you will learn about our experiments with HAProxy in the past, our current HAProxy use cases, and the plan for replacing the existing stack with HAProxy. We will also talk about our evaluation process, why HAProxy came out as a winner, and how we are planning to leverage HAProxy’s features to modernize our traffic stack which will make us better prepared for the future.
Here you can view the slides used in this presentation if you’d like a quick overview of what was shown during the talk.