Mastering Kubernetes - Second Edition

Zero-downtime

Finally, we arrive at the zero-downtime system. There is no such thing as a zero-downtime system. All systems fail and all software systems definitely fail. Sometimes, the failure is serious enough that the system or some of its services will be down. Think about zero-downtime as a best-effort distributed system design. You design for zero-downtime in the sense that you provide a lot of redundancy and mechanisms to address expected failures without bringing the system down. As always, remember that even if there is a business case for zero-downtime, it doesn't mean that every component must be.

The plan for zero-downtime is as follows:

• Redundancy at every level: This is a required condition. You can't have a single point of ...