Building a Unified Cross‑Cluster Network Plane with Kube‑OVN for TiDB Deployment

At KubeCon China 2021, PingCAP engineer Sei Jin presented a solution based on Kube‑OVN that creates a unified network plane across multiple Kubernetes clusters to satisfy Japanese customers’ need for cross‑cluster TiDB deployment.

The presentation highlighted why users seek cross‑cluster networking: ensuring service availability across multiple data‑centers, separating workloads across cloud providers, providing an escape route from vendor lock‑in, and meeting hybrid‑cloud compliance requirements.

Three typical approaches were examined: IPv6‑only clusters, public‑cloud vendor solutions, and the Kube‑OVN solution. Kube‑OVN was chosen because it can build a unified overlay network in private environments without the high cost and complexity of IPv6 allocation or vendor‑specific limitations.

Kube‑OVN’s key features were described:

Flexibility – supports three‑layer overlay networks, independent PVC/ACL, IP mobility across nodes, multi‑tenant namespaces, and both distributed and centralized gateways.

Efficiency – provides an underlay network that allows pods to communicate directly with physical or virtual machines, supports VLANs, and enables high‑performance traffic with optional packet encapsulation.

Security – enriches Kubernetes network policies, offers full‑flow traffic mirroring for audit, and improves overall container network security.

A live demo was conducted using two single‑node Kubernetes clusters, each acting as a gateway, to showcase:

Multi‑cluster network plane creation and verification of inter‑cluster NGINX pod connectivity.

MySQL ↔ WordPress communication across clusters to test layer‑4 networking.

TiDB ↔ WordPress connectivity, demonstrating TiDB’s MySQL compatibility within the unified network. All demo scripts are available at https://github.com/it2911/kube-ovn-demo . The article also provides links to Kube‑OVN’s website, GitHub repository, Slack channel, and contact information for the enterprise edition.