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“We started in 2017 with Calico and never regretted it!”
—Stefan Fudeus, Product Owner/Lead Architect, 1&1 Mail & Media
Challenge
1&1 Mail & Media, part of the IONOS group, powers popular European internet brands including GMX and Web.de, serving more than 50% of Germany’s population with critical identity and email infrastructure. With roughly 45 to 50 million users, network reliability is non-negotiable. Any downtime could affect millions.
By 2022, the company had containerized 80% of its workloads on Kubernetes across three self-managed data centers. While the platform, backed by bare metal nodes and custom network layers, was highly scalable, network throughput bottlenecks began to emerge. Pods were limited to 2.5 Gbps of bandwidth due to IP encapsulation overhead, despite 10 Gbps network interfaces.
The team needed a solution that:
- Improved pod-to-pod network performance
- Maintained strong network policy isolation across up to 40 tenants per cluster
- Scaled to millions of network connections and 1.4 million HTTP requests per second
Solution
1&1 Mail & Media had adopted Calico back in 2017, largely for its unique Kubernetes NetworkPolicy standard support. As their Kubernetes platform evolved, with clusters scaling to 300 bare metal nodes, 16,000 pods, and over 4 million Continue reading