Real-Time Replication
The real-time replication of the data between the active and standby nodes is done using MySQL replication, as most appliance data is stored in MySQL database tables.
Each node is configured to replicate its databases as defined by the failover membership. The software layer responsible for the real time replication of the data dynamically configures MySQL according to the current state of the failover membership and continuously monitors the progress of the replication recovering any non-fatal error.
MySQL replication provides real-time latency while being very reliable. An SQL replication is usually done in less than two seconds and the protocol correctly handles temporary network disconnection. The volatile data stored in memory and the configuration files stored on disk of the current active appliance are replicated on the standby node every minute.