>>publishing to and consumption from the partition will halt and will not resume until the faulty leader node recovers
Can you confirm that's the case? I think they won't wait until leader recovered and will try to elect new leader from existing non-ISR replicas? And in case if they wait, and faulty leader never comes back? On Thu, Oct 24, 2013 at 6:24 AM, Aniket Bhatnagar < aniket.bhatna...@gmail.com> wrote: > Thanks Neha > > > On 24 October 2013 18:11, Neha Narkhede <neha.narkh...@gmail.com> wrote: > > > Yes. And during retries, the producer and consumer refetch metadata. > > > > Thanks, > > Neha > > On Oct 24, 2013 3:09 AM, "Aniket Bhatnagar" <aniket.bhatna...@gmail.com> > > wrote: > > > > > I am trying to understand and document how producers & consumers > > > will/should behave in case of node failures in 0.8. I know there are > > > various other threads that discuss this but I wanted to bring all the > > > information together in one post. This should help people building > > > producers & consumers in other languages as well. Here is my > > understanding > > > of how Kafak behaves in failures: > > > > > > Case 1: If a node fails that wasn't a leader for any partitions > > > No impact on consumers and producers > > > > > > Case 2: If a leader node fails but another in sync node can be become a > > > leader > > > All publishing to and consumption from the partition whose leader > failed > > > will momentarily stop until a new leader is elected. Producers should > > > implement retry logic in such cases (and in fact in all kinds of errors > > > from Kafka) and consumers can (depending on your use case) either > > continue > > > to other partitions after retrying decent number of times (in case you > > are > > > fetching from partitions in round robin fashion) or keep retrying until > > > leader is available. > > > > > > Case 3: If a leader node goes down and no other in sync nodes are > > available > > > In this case, publishing to and consumption from the partition will > halt > > > and will not resume until the faulty leader node recovers. In this > case, > > > producers should fail the publish request after retrying decent number > of > > > times and provide a callback to the client of the producer to take > > > corrective action. Consumers again have a choice to continue to other > > > partitions after retrying decent number of times (in case you are > > fetching > > > from partitions in round robin fashion) or keep retrying until leader > is > > > available. In case of latter, the entire consumer process will halt > until > > > the faulty node recovers. > > > > > > Do I have this right? > > > > > >
