In the appliance's application server log file you might notice messages related to replication module (ZMQ) that appears to be errors but are just normal behaviors.

'SKL-ERR-4011: did not add replicated object to database - already exists locally'

This message is related to the replication. The ZMQ BacklogProcessor (BLP) tries to resend the objects from replication table if the replication module could not receive the acknowledgement (ACK) from other node in time in first attempt. Once it receives the ACK from other node, it starts pushing the records. If BLP would have sent multiple requests for the same records, it will try to send the same records multiple times and receiving node will start throwing this message for all the additional requests after replicating the record from first request. This message should disappear once all the additional replication requests get drained.