ORA-16662: Network Timeout When Contacting A Member

Cause:

The connection string for DGConnectIdentifier, which uses the failover_mode option, has a problem when contacting a member in RAC database.

primarydb = "(description=(address_list=(address=(protocol=tcp)(host=<scan_name>)(port=<port>)))(connect_data=(server=dedicated)(service_name=<service_name>)(ur=a)(failover_mode=(type=select)(method=basic)(retries=180)(delay=5))))"
 standbydb = "(description=(address_list=(address=(protocol=tcp)(host=<scan_name>)(port=<port>)))(connect_data=(server=dedicated)(service_name=<service_name>)(ur=a)(failover_mode=(type=select)(method=basic)(retries=180)(delay=5))))"

And the DGConnectIdentifier identifier should not use failover_mode in the connection string.

Solution:

The connection string in DGConnect identifier is using failover_mode option.

Remove the failover_mode from the connection string and use the connection string for both databases as shown below:

primarydb =
   (DESCRIPTION =
   (ADDRESS_LIST =
   (ADDRESS=(PROTOCOL = TCP)(HOST=<scan_name>)(PORT = <port>))
   )
   (CONNECT_DATA =
   (SERVER = DEDICATED)
   (SERVICE_NAME = <service_name>)
   )
   )
         standbydb =
   (DESCRIPTION =
   (ADDRESS_LIST =
   (ADDRESS=(PROTOCOL = TCP)(HOST=<scan_name>)(PORT = <port>))
   )
   (CONNECT_DATA =
   (SERVER = DEDICATED)
   (SERVICE_NAME = <service_name>)
   )
   )