What is best conection string for application to connect to active standby

Question

I have setup a primary db and an active standby database on two servers in different city.
Now for people to test it, what is the best tnsnames strings I should provide to them?
Plus how do I test it?
Thanks in advance.

Answer 1

Hello;
What you are looking at Transparent Application Failover for Data Guard. ( Way cool idea if you decide to use it )
Example
ernie =
(DESCRIPTION =
    (ADDRESS_LIST =
       (ADDRESS = (PROTOCOL = TCP)(HOST = Primary.server.com)(PORT = 1521))
       (ADDRESS = (PROTOCOL = TCP)(HOST = Standby.server.com)(PORT = 1521))
       (CONNECT_DATA =
       (SERVICE_NAME = ernie)
)The DBMS_SERVICE.CREATE_SERVICE will let create an alias for database which can be used on both servers so the end user never sees a failover.
The rough outline is
1. Create the service
BEGIN
   DBMS_SERVICE.CREATE_SERVICE('ernie','ernie');
END;
/2. Start the service
BEGIN
   DBMS_SERVICE.START_SERVICE('ernie');
END;
/3. default parameters can now be set for 'ernie'.
BEGIN
   DBMS_SERVICE.MODIFY_SERVICE
   ('ernie',
   FAILOVER_METHOD => 'BASIC',
   FAILOVER_TYPE => 'SELECT',
   FAILOVER_RETRIES => 200,
   FAILOVER_DELAY => 1);
END;
/4. Finally a database STARTUP trigger should be created to ensures that this service is only offered if the database is primary.
CREATE TRIGGER CHECK_ERNIE_START AFTER STARTUP ON DATABASE
DECLARE
V_ROLE VARCHAR(30);
BEGIN
SELECT DATABASE_ROLE INTO V_ROLE FROM V$DATABASE;
IF V_ROLE = 'PRIMARY' THEN
DBMS_SERVICE.START_SERVICE('ernie');
ELSE
DBMS_SERVICE.STOP_SERVICE('ernie');
END IF;
END;
/A complete document is available here :
http://uhesse.wordpress.com/2009/08/19/connect-time-failover-transparent-application-failover-for-data-guard/
Best Regards
mseberg