Cassandra Multi-Region Active-Active Architecture

Cassandra Multi-Region Active-Active Architecture An architecture diagram generated by Archify. Client Traffic · HTTP / X-Source-Region · Architecture component Client Traffic HTTP / X-Source-Region Global Router · nginx :8100 · Architecture component · failover router Global Router nginx :8100 failover router app-us · Spring Boot :8180 · Datacenter 1: us-east-1 (RF=3) · local DC · Spring app-us Spring Boot :8180 local DC cassandra-us-1 · seed node :9042 · Datacenter 1: us-east-1 (RF=3) · rack 1a cassandra-us-1 seed node :9042 rack 1a cassandra-us-2 · peer node · Datacenter 1: us-east-1 (RF=3) · rack 1b cassandra-us-2 peer node rack 1b cassandra-us-3 · peer node · Datacenter 1: us-east-1 (RF=3) · rack 1c cassandra-us-3 peer node rack 1c app-eu · Spring Boot :8181 · Datacenter 2: eu-west-1 (RF=3) · local DC · Spring app-eu Spring Boot :8181 local DC cassandra-eu-1 · seed node :9142 · Datacenter 2: eu-west-1 (RF=3) · rack 1a cassandra-eu-1 seed node :9142 rack 1a cassandra-eu-2 · peer node · Datacenter 2: eu-west-1 (RF=3) · rack 1b cassandra-eu-2 peer node rack 1b cassandra-eu-3 · peer node · Datacenter 2: eu-west-1 (RF=3) · rack 1c cassandra-eu-3 peer node rack 1c HTTP us-east-1 eu-west-1 LOCAL_QUORUM LOCAL_QUORUM cross-DC replication Datacenter 1: us-east-1 (RF=3) Datacenter 2: eu-west-1 (RF=3) Legend Backend Database Cloud External

Active-Active Writes

  • • Both regions accept local writes independently with LOCAL_QUORUM
  • • No single writer bottleneck; lower write latency for all users

Datacenter-Local Isolation

  • • Java driver contacts only local Cassandra nodes to preserve latency and SLAs
  • • Losing one node per region still maintains full local quorum availability

Cross-DC Sync & Failover

  • • NetworkTopologyStrategy replicates rows asynchronously across datacenters
  • • Global router fails over traffic to surviving region during full DC outage
📍 Case 1: Aurora HA (Single Writer)⚡ Case 2: Cassandra (Active-Active)🔄 HTTP Sync vs Queue Async Flows