Oracle Error Message
ORA-16855: transport lag has exceeded specified threshold
Reason for the Error
The current transport lag exceeded the value specified by the ‘TransportLagThreshold’ database property. It is caused by either poor network performance between the redo source and the standby databases or a network disconnection.
Solution
Check the network connection between the redo source and standby databases. If they are connected, check the network performance between the redo source and the standby databases and tune it if necessary.