Tarun, In 0.7, there is no producer side ack.
In 0.8, sync producer will wait for an ack and is blocking. If the ack is lost because a broker is down, sync producer will timeout and it's up to the caller to decide what to do. If the caller chooses to resend, it's possible for duplicated messages to show up in the broker. Thanks, Jun On Mon, Jun 25, 2012 at 8:12 AM, Tarun Kumar <agrawal.taru...@gmail.com>wrote: > Hi, > > I have a couple of questions related to Sync Producer. > > 1. From what i know (please correct me if i am wrong), Sync producer send > is a blocking call. Until acknowledgement is received from broker, next > message is not sent by producer. > > 2. what if ack is lost. Is there any kind of timeout till when producer > waits for ack. If yes, does it try to resend same message? > If yes, duplicate message might reach to broker (due to previous message's > ack timeout). How does kafka avoids that? > > 3. What are different possibilities of duplicate messages being stored at > broker? > > Thanks, > Tarun >
