When a replication server detects that a directory server is out of sync regarding the overall updates made in the topology, that directory server is said to have a degraded status. A directory server that is out of sync is unlikely to be able to send the expected acknowledgments in time for the replication server to avoid a timeout situation. The server therefore has a degraded status until it has an acceptable level of updates. With a degraded status, a directory server is no longer expected to send acknowledgments to the replication server, until it returns to having a normal status.
Because a directory server with a degraded status is unable to send acknowledgments, the synchronization of an LDAP operation in safe read mode cannot be assured. In other words, data read from this directory server might not contain the modifications made on another directory server in the topology.
For more information, see Replication Status Definitions.