Calico Load Balancer: Simplifying Network Traffic Management with eBPF

Authors: Alex O’Regan, Aadhil Abdul Majeed

Ever had a load balancer become the bottleneck in an on-prem Kubernetes cluster? You are not alone. Traditional hardware load balancers add cost, create coordination overhead, and can make scaling painful. A Kubernetes-native approach can overcome many of those challenges by pushing load balancing into the cluster data plane. Calico Load Balancer is an eBPF powered Kubernetes-native load balancer that uses consistent hashing (Maglev) and Direct Server Return (DSR) to keep sessions stable while allowing you to scale on-demand.

Below is a developer-focused walkthrough: what problem Calico Load Balancer solves, how Maglev consistent hashing works, the life of a packet with DSR, and a clear configuration workflow you can follow to roll it out.

Why a Kubernetes-native load balancer matters

On-prem clusters often rely on dedicated hardware or proprietary appliances to expose services. That comes with a few persistent problems:

• Cost and scaling friction – You have to scale the network load balancer vertically as the size and throughput requirements of your Kubernetes cluster/s grows.
• Operational overhead – Virtual IPs (VIPs) are often owned by another team, so simple service changes require coordination.
• Stateful failure modes – Kube-proxy load balancing is stateful per node, Continue reading