Urgent plz+ how to release locks when instance crashes

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03-21-2007, 12:27 PM
janki_mehta

Urgent plz+ how to release locks when instance crashes

i have a database service connected to Oracle 9i and it is connected to database using jdbc drivers.

now if due to instance failure, that service and stops and then i restart the web server and run a program for recovery. This recovery program rollbacks all transactions after last commit in transaction that was going on at time of failure.

Database is intact and not restarted. If we restart it, PMON itself will release locks. But here, how to release locks and do rollback..coz memory would have effect of queries executed before failure + locks held ...since database is not restarted in this case.

What should be done?
03-21-2007, 12:38 PM
pando

instance recovery is automatic, I am not really sure what is your point
03-21-2007, 12:39 PM
dbasan

Kill the process if its held a exclusive lock.
03-21-2007, 01:16 PM
PAVB

Can you please define for us what you mean with "instance failure". It is hard to read that followed by "Database is intact and not restarted"
03-22-2007, 06:01 AM
janki_mehta

instance failure means..

service that did connectivity with database and was firring queries and say electricity went and transactions holded locks, but that service needs to be restarted on server and rollback/resubmit those transactions
03-22-2007, 06:03 AM
janki_mehta

kill what? how to find which process to kill?

Quote:

Originally Posted by dbasan

Kill the process if its held a exclusive lock.

kill what? how to find which process to kill?
03-22-2007, 06:04 AM
davey23uk

what happened to your database, did it crash and go down?
03-23-2007, 07:32 AM
reydp

Correct me if I'm wrong, you might be referring to a session from the application server to the database server that was caught trap when let's say application server error occured and not really the instance referred usually here as the database instance.

If my guess is right, you wanted to clear those session that could still be in the database server, and from the application server you have a facility to undo this incomplete transaction.

Well, the database itself has a facility to clean those session that are considered dead connection. But if you really need something from the oracle database to detect and disconnect those dead connection as soon as possible, As far as I can remember there is a way to do that, and it is configured in sqlnet.ora. Please research on Dead Connection Detection.