Hi Parth, Thanks for your reply. This could work, as the problem domain has a unique Id in the incoming stream, but I believe the db will be Cassandra, which updates instead of throwing errors when inserting a duplicate key. So I can't rely on that.
Best regards, JG On Mar 3, 2015 12:45 PM, "Parth Brahmbhatt" <[email protected]> wrote: > Do you have some uniqueness in messages based on which you can define a > DB constraint ? If there is one you define a unique constraint in DB, if > the spout retries the bolt writing to DB will fail with constraint > violation and the exception should also tell you which constraint was > violated, you can ignore the unique constraint violations and ack back so > the spout will stop retrying. > > Its not clean but should work. > > Thanks > Parth > > From: Javier Gonzalez <[email protected]> > Reply-To: "[email protected]" <[email protected]> > Date: Tuesday, March 3, 2015 at 9:37 AM > To: "[email protected]" <[email protected]> > Subject: Exactly once transactions and storm > > We don't see the need for batching, and we don't quite see how Trident > would help us in this case. If you could offer suggestions of alternatives > (or point out what are we missing about Trident), we would be very grateful. > >
