role-database:replication-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, Ca...
SKILL.md
Full skill instructions
Replication & High Availability
Reference Files
Load from references/ based on what's needed:
references/engine-replication.md
Replication modes comparison (synchronous/semi-sync/async) with durability and latency tradeoffs. PostgreSQL: streaming replication config, logical replication publications/subscriptions, replication slot warnings. MySQL: GTID setup, semi-synchronous plugin config, Group Replication overview. MongoDB: write concern levels, read preference options, replica set architecture. Redis: Sentinel config (quorum, timeouts), Cluster mode hash slots overview. Cassandra: NetworkTopologyStrategy, LOCAL_QUORUM vs EACH_QUORUM vs LOCAL_ONE. Consensus protocols table (Raft, Paxos, Gossip, ISR). Load when: configuring replication for a specific engine or choosing a topology.
references/failover-monitoring.md
Failover types (automatic, manual, semi-automatic) and Patroni overview. Split-brain prevention techniques (quorum, STONITH, watchdog, min replica count). Topology reference (primary-secondary, multi-primary, quorum-based) with supported engines. Replication monitoring metrics table with alert thresholds for all engines. PostgreSQL replication lag queries (pg_stat_replication, pg_replication_slots). MySQL SHOW REPLICA STATUS key fields. Load when: setting up failover automation, monitoring replication health, or building incident runbooks.