role-databasereplication-ha

High availability and replication topologies across all database engines. Synchronous/asynchronous/semi-synchronous replication, primary-secondary, multi-primary, quorum-based. PostgreSQL streaming/logical replication, MySQL GTID/Group Replication, MongoDB replica sets, Redis Sentinel/Cluster, Cassandra multi-DC. Consensus protocols (Raft, Paxos, Gossip). Failover automation, split-brain prevention. Use when designing HA architectures, configuring replication, or troubleshooting failover.