Active-Active vs. Active-Passive: A Practical Guide
TL;DR: Active-active runs every node live so traffic distributes across the pool and failover is near-instant, but it forces you to solve multi-writer conflicts through last-writer-wins, vector clocks, CRDTs, or consensus protocols. Active-passive keeps one authoritative primary with an idle standby, trading seconds to minutes of promotion time for predictable behavior, simpler troubleshooting, and lower cost under steady load.