Oracle Forms 10g runtime handling during RAC node failover.

Question

Hi,
Forms version 10g R2 (10.1.2.0.2)
Oracle DB version 10g R2 RAC with 3 nodes.
If the RAC DB node that the user is connected to goes down, the user gets FRM-40733 and ORA-03114 error messages and the client forms application gets locked down/ goes in a loop with the error messages. The user has to close the browser to get out of the loop. I understand that this is the expected behaviour, but I'm wondering whether we can trap the error ORA-03114 and fire the "key-exit" trigger to get out of the application.
Have any one implemented a clean way to exit the Forms application when the RAC DB node goes down..?
I'm looking for some suggestions or an elegant way to handle the above failure.
Thank you in advance.
Sudhakar

Answer 1

Glen,
I haven't solve this one yet.I have been playing around with the following:
In my environment, I am still using 6i (not web) forms/reports.
My clients are XP, NT, 2000.
I have the forms/report runtime installed on their PCs.
Their TNSNAMES.ORA will be pointing to PRIMARY ( PDB)
If a SWITCHOVER or FAILOVER happens to the physical standby (SDB), I want a trigger to kick a batch file that will manipulate the TNSNAME.ORA on each clients stations.
On the standby
CREATE OR REPLACE TRIGGER change_tns
AFTER DB_ROLE_CHANGE ON DATABASE
DECLARE
role VARCHAR2(30);
dbname varchar2(100);
BEGIN
SELECT
DATABASE_ROLE,
DB_UNIQUE_NAME
INTO
role,
dbname
FROM
V$DATABASE;
IF role = 'PRIMARY' and dbname='SDB' THEN
dbms_scheduler.create_job(
job_name=>'move_sqlnet',
job_type=>'executable',
job_action=>'c:\temp\movetns.cmd',
enabled=TRUE
ELSE
-- if the standby >was< PRIMARY,
-- but the primary comes BACK on line,
-- need to reverse the step above.
END IF;
END;
As for the movetns.cmd
something like
rem -- attach to the workstation,
net use m: \\station name\share name
rem -- stdb_tnsname.ora would be pointing to STANDBY
copy stdb_tnsname.ora m:\orant\net80\tnsname.ora
net use m: /delete
rem -- need to do that for all workstations..
As you can see, there could be lots of problems with this procedure.
Client doesn't know about the failover, starts a RE-BOOT on the pc, therefore, the new tnsnames.ora will not get to client.. what to do for that client? Do i re-run the batch ...every hour?
tell me if you come up with an answer..
p-