Evolution of Direct Server Return Implementation for Containerized Applications

Explore the evolution of Direct Server Return (DSR) implementation for containerized applications in this Linux Plumbers Conference talk. Dive into Meta's journey of adapting DSR technology for L4 load balancing as their infrastructure transitioned from isolated machine subsets to a more efficient multi-tenant shared pool model. Learn about the challenges faced when moving services to network namespaces and the solutions developed, including the "rootlet" XDP program array and the XDP Chainer. Discover how the introduction of multi-tenancy and network namespaces necessitated a reevaluation of decapsulation support for backends, leading to the migration of the decapsulation data path to a TC-BPF solution. Gain insights into the obstacles encountered, alternatives considered, and lessons learned throughout this project, as well as the benefits achieved with the new approach.