Question

We have a service method which does approximately the following:

@Transactional
public void serviceMethod(...){
   for(Item i : bunchOfItems){
      webServices.webServiceCall(...);
      dao.daoUpdateMethod(...);
   }
}

The problem is that as soon as an update occurs the DB is holding a lock on the table for the duration of the Transaction (webservice calls average 5 sec each). Any exception in a webservice call or DAO call should, of course, cause a full rollback.

What’s the best approach to this situation?

Answer 1

By employing MVCC mode in the database I can avoid locking on updates altogether. After doing this I can perform the same test without any lock contention.

MVCC mode allows reads to occur while an uncommitted update is still in progress.