Your Kubernetes cluster just went down. Now what?

Hey there,

Even the most stable Kubernetes deployments can face unexpected disruptions. One moment, everything is stable; the next, a single regional cloud failure brings the whole system down.

That kind of scenario is exactly why many teams adopt multi-cluster Kubernetes deployments. It might sound complex, and it is, but once downtime means lost revenue or unhappy users, having another cluster ready to go becomes essential.

In today’s issue, we look at:

• Why connecting clusters matters beyond redundancy

• How Cilium eliminates the sidecar overhead problem

• What a real-world multi-cluster setup looks like on Civo.

Let’s dive in.

Most multi-cluster setups have relied on sidecars, extra proxy containers that handle communication between services. Every pod needs one, which adds CPU, memory, and maintenance overhead. At scale, that overhead becomes significant.

When Istio released Ambient Mesh in 2022, they highlighted challenges with sidecars: modifying pod specs, restarting applications during upgrades, and the computational cost of traffic processing. For large deployments, these factors add complexity and resource overhead.

Cilium takes a different approach using eBPF, a Linux kernel feature that runs programs safely inside the operating system. Instead of deploying sidecars everywhere, Cilium handles networking directly at the node level. The result is fewer moving parts, less resource usage, and simpler operations.

Cilium’s ClusterMesh feature connects multiple Kubernetes clusters seamlessly. In a typical setup on Civo, two or more clusters in the same virtual network can communicate securely, share services like logging, DNS, and secrets, and distribute workloads across clusters. This reduces duplication and simplifies operations across environments.

Traffic between clusters is automatically routed, and mutual TLS ensures all communication is encrypted. Built-in connectivity tests and diagnostics make it easier to confirm that clusters are talking to each other correctly. Even as your application scales, ClusterMesh keeps multi-cluster management reliable and straightforward, giving teams a clear picture of how workloads interact across clusters.

Check out the full implementation guide here for a complete walkthrough of setup, troubleshooting, and deployment on Civo.

Curated resources to deepen your understanding of Cilium, eBPF, and multi-cluster Kubernetes deployments.

Setting up Cluster Mesh: A step-by-step walkthrough for enabling ClusterMesh and linking multiple Kubernetes clusters.

Multi-cluster Kubernetes: Benefits, Challenges, and Tools: Explore why teams adopt multi-cluster setups and the key considerations for success.

Cilium Network Policies, from first principles to production: Understand and implement Cilium network policies, from foundational concepts to real-world deployment.

Safely Managing Cilium Network Policies in Kubernetes: Testing and Simulation Techniques: Learn how to test and simulate Cilium network policies before rolling them out in production.

eBPF – The Best Kept Secret in Technology: Discover how eBPF is transforming networking and observability in modern systems.

And it’s a wrap!

See you Friday for the week’s news, upcoming events, and opportunities.

If you found this helpful, share this link with a colleague or fellow DevOps engineer.

Divine Odazie
Founder of EverythingDevOps