My Database version - Mysql 3.23.58

I have a table with one identity column containg say 2000 records
One of the thread in my application tries to update all the 2000 records one by one.

Problem i am facing actually is some of the records doesn't get updated.

To my astonishment i am not getting any exceptions.

For u'r clear understanding,take a look at the code given below

void update(Object obj) {

Session session =
new Configuration().configure().buildSessionFactory().openSession();
Transaction tx = session.beginTransaction();
CDR cdrObj = (CDR) obj;
cdrObj.setStatus ("O");
session.update (cdrObj);
tx.commit();
session.connection().createStatement().execute("SHUTDOWN");
session.close();

}

This particular function gets called for 2000 times in a continous running thread....

Can anybody guess out wht could be the problem & where i am going wrong...