from my understanding failING over over has nothing to do with replication (except that replication is a method to have failover database as such).

Here is what I remember from my last investigation into that topic (Oracle v805):

For TAF(Transparent application failover) Parallel Server is required - so this is not your case. In addition to, applications must be aware and properly coded to take this advantage. I am not sure that eg. Oracle Forms supports such thing. And failover can not failover everything: maximum you can continue previous queries, but not DML transactions.

For listeners failover see: Connect-Time Failover for Multiple Listeners.


So I think feasable scenariou is like that: applications are restarted by users or applications detect broken connection and restart themselfs automatically.
never tried but probably you can use multiply descriptions and multiply addresses feature of tnsnames.ora to force client to try serveral servers untill it finds working one. TAF related parameters in tnsnames.ora should have no effect w/o Parallel Server.