Hans What you state would work for aggregations, but not for state machines and CEP.
Regards Sab On 19 Mar 2017 12:01 a.m., "Hans Jespersen" <h...@confluent.io> wrote: > The only way to make sure A is consumed first would be to delay the > consumption of message B for at least 15 minutes which would fly in the > face of the principals of a true streaming platform so the short answer to > your question is "no" because that would be batch processing not stream > processing. > > However, Kafka Streams does handle late arriving data. So if you had some > analytics that computes results on a time window or a session window then > Kafka streams will compute on the stream in real time (processing message > B) and then later when message A arrives it will put that message back into > the right temporal context and publish an amended result for the proper > time/session window as if message B were consumed in the timestamp order > before message A. The end result of this flow is that you eventually get > the same results you would get in a batch processing system but with the > added benefit of getting intermediary result at much lower latency. > > -hans > > /** > * Hans Jespersen, Principal Systems Engineer, Confluent Inc. > * h...@confluent.io (650)924-2670 > */ > > On Sat, Mar 18, 2017 at 10:29 AM, Ali Akhtar <ali.rac...@gmail.com> wrote: > > > Is it possible to have Kafka Streams order messages correctly by their > > timestamps, even if they arrived out of order? > > > > E.g, say Message A with a timestamp of 5:00 PM and Message B with a > > timestamp of 5:15 PM, are sent. > > > > Message B arrives sooner than Message A, due to network issues. > > > > Is it possible to make sure that, across all consumers of Kafka Streams > > (even if they are across different servers, but have the same consumer > > group), Message A is consumed first, before Message B? > > > > Thanks. > > >
