I would suggest ruling out the following, if you haven't already: 1. The same service is not advertised in multiple instances/databases 2. The same user/password does not work with multiple databases (just for the purity of the test) Please post the TNS names entry and the secondary entry if you are using a backup TNS names. -Krish _____ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of steve montgomerie Sent: Monday, May 05, 2008 7:17 AM To: oracle-l@xxxxxxxxxxxxx Subject: TAF FUN - Call me crazy I'm seeing TAF fail me over to a different database. As anyone seen this behavior? Can anyone reproduce this? Here's the simple test case...... OEL 4.5 / Oracle 10.2.0.4 4 nodes 3 databases Each node has an instance of all db's so 3 instances per node * 4 1.connect to db_A from my client 2.select * from all objects from my client 3.from the server kill the instance that is running the query 4.query stops for a second or two and then continues on a different instance on a different node 6.Yeah TAF works!! 7.From same session conn user@db_B *note different database 8.select * from all objects from my client 9.from the server kill the instance that is running the query resulting ora-1555 10.from the same client session in step 7&8 select instance name from v$instance results in db_A <= It failed me over to a completely different database 11 TAF no work - bummer