An active-active cluster refers to a cluster containing two availability zones (usually independent data centers). These two domains can independently provide computing and storage services, typically located in the same geographical area. This setup ensures that if one domain fails, data can be recovered from the other domain, guaranteeing service continuity. When both availability zones are operating normally, the cluster stores a replica of each data block in both zones. If one availability zone fails, the complete data can be retrieved from the surviving zone to restore services.
