Open-sourcing Katran, a scalable network load balancer

What this post added

This post introduces Katran, a new software-based network load balancer for Facebook's infrastructure. Katran leverages eXpress Data Path (XDP) and the eBPF virtual machine to reengineer the forwarding plane, enabling it to run on commodity Linux servers and coexist with other services. This design improves performance and scalability by handling packets earlier in the network stack, reducing inefficiencies like busy loops, and allowing for colocation with backend servers. The first-generation L4LB relied on IPVS and separate machines for load balancing and backend services, which had drawbacks in terms of vulnerability to load increases and failure domain separation. Katran addresses these by offering a more flexible and efficient software-based solution.