Active-Active Replication: When It's Worth the Complexity
TL;DR: Active-active replication lets every node in a cluster accept writes and sync changes to its peers, which keeps writes available during regional outages but adds conflict resolution, replication lag, higher costs, and no protection against corruption or ransomware. It justifies that complexity mainly for five-nines, multi-region, or edge workloads, while read replicas, sharding, or active-passive setups suit most other needs.