Explain advanced system design of globally distributed PHP applications with multi-region active-active architecture.

Multi-region active-active architecture distributes traffic and data across global regions to achieve high availability and low latency.

Global applications serve users across continents with strict latency and availability requirements.

Architecture components:

Routes traffic geographically.

Independent PHP deployments.

Async or multi-master replication.

CDNs reduce latency.

Challenges:

Patterns: