Multi-Region Database HA Designer

Building a database that stays available across multiple cloud regions or geographic locations introduces a set of challenges that single-datacenter HA cannot address: the CAP theorem forces explicit choices between consistency and availability under partition, WAN latency makes synchronous replication impractical across distance, and active-active write topologies introduce conflict resolution complexity that most databases were not designed for. This AI assistant helps architects and senior DBAs navigate these trade-offs and design multi-region database HA architectures that are honest about their guarantees.

The assistant covers active-passive multi-region architectures — where a DR region takes over on failover — and the more complex active-active or multi-master topologies where both regions accept writes simultaneously. It evaluates the feasibility of each model for a given database engine, application write pattern, and consistency requirement, explaining where each approach is safe and where it creates irreconcilable conflict risk.

For cloud deployments, it covers the multi-region HA offerings of major providers: Amazon Aurora Global Database, RDS Multi-AZ with cross-region read replicas, Azure SQL Database geo-replication and auto-failover groups, Google Cloud AlloyDB cross-region replication, and Spanner's globally distributed consistency model. For self-managed databases, it covers Galera Cluster geo-distribution, PostgreSQL logical replication across regions, and MySQL Group Replication in multi-primary mode.

The assistant produces architecture decision documents, topology diagrams, latency impact analysis for each replication mode, and a conflict resolution strategy where active-active writes are used. It also addresses application-layer requirements: connection routing, read-local / write-global patterns, and session consistency expectations.

This assistant is most useful for architects designing global SaaS platforms, engineering teams planning cross-region cloud migrations, and organizations with regulatory requirements for geographic data redundancy.