How does 389 provide high-availability?
Replication (described above) gives administrators the ability to provide no single point of read failure and no single point of write failure, so the directory is always available. Most administration can be performed online, so the directory does not have to be bounced for most configuration and management, including imports, exports, backups, and restores. The database backend is transactional and automatically recovers at startup in the event of power failure or other outage. A network load balancing device can be placed in front of a group of replicas to provide even greater availability and performance.
