Episode 55 — Fault Domains and Update Domains: planning for “planned failure” events
CloudNetX scenarios often assume you can design for failure that is scheduled, not just failure that is accidental, and this episode explains fault domains and update domains as tools for surviving planned disruption. It defines fault domains as groups of resources that share underlying hardware or infrastructure risk, meaning they can fail together even if instances are separate. It defines update domains as groupings that are updated together during maintenance cycles, which directly affects whether a service experiences downtime during patching. The first paragraph focuses on the practical meaning: if all replicas live in the same domain, a single maintenance or hardware event can remove them all at once, so domain-aware placement is a core availability control.
