ECDA 15.0 and earlier supports replication into an Oracle instance, even if that instance is a node in a RAC system. However, if the configured node fails, ECDA 15.0 and earlier does not support automatically going to another node in the RAC system.
As of ECDA 15.0 ESD #1, automatic failover when replicating into a RAC system is supported.
Workaround: If the node that the ECDA service is connected to fails, reconfigure the ECDA service to use a different node in the RAC system.