Replication allows writes to be directed to any directory server in the topology. Distributing write operations in a round-robin fashion, however, may introduce conflicts. In particular, distributing a series of LDAP Add, Delete and Modify DN operations targeting the same DN in quick succession can result in conflicts that require manual intervention. The Assured Replication feature can help prevent conflicts created by the same client application.
If possible, consider using server affinity with the load balancer that either associates a client IP address or a client connection with a single directory server instance at a time. Also, consider using the PingDirectoryProxy Server for load balancing LDAP traffic. The Server Affinity feature in the Directory Proxy Server enables replication-friendly load balancing.