ADMINISTERING
When the server availability index falls to a point where it is equal to or less than the server availability threshold that you set, the server is designated as BUSY.
When a server is BUSY, access requests fail over to another server in the cluster, if one is available. If no other server is available, the original server takes the access request, even though it is BUSY. No request is denied access because a server is in a BUSY state. Each time an access request is redirected, Domino® generates a workload balancing event in the Domino server log file.
The server availability threshold does not affect replication. Replication occurs even when a server is in a BUSY state.