Hello Guozhang, Thank you for your reply.
> setting to "0" will actually mean to commit every time. Hum, I somehow misunderstood the code. Now I understand that is true. > You should actually set it to Long.MAX_VALUE to indicate "not commit regularly by intervals" I see. I'd consider taking that approach! Another question just from curiosity: >From looking at code, setting `commit.interval.ms` to a negative value can also indicate "not commit regularly by intervals." In other words, it has the same effect as setting it to Long.MAX_VALUE. Is this true? The implication of setting the property to a negative value is undocumented, so I'm thinking setting it to Long.MAX_VALUE is preferable. Thank you. Tomoyuki On Sat, Oct 13, 2018 at 1:48 AM Guozhang Wang <wangg...@gmail.com> wrote: > Hello Tomoyuki, > > 1. Seems a good use case for Streams. > 2. You should actually set it to Long.MAX_VALUE to indicate "not commit > regularly by intervals", setting to "0" will actually mean to commit every > time. Then you can leverage on ProcessorContext.commit() to manually commit > after the batch is done. > > > Guozhang > > > > > On Wed, Oct 10, 2018 at 11:15 PM, Tomoyuki Saito <aocch...@gmail.com> > wrote: > > > Hi, > > > > I'm exploring whether it is possible to use Kafka Streams for batch > > processing with at-least-once semantics. > > > > What I want to do is to insert records in an external storage in bulk, > and > > execute offset-commit after the bulk insertion to achieve at-least-once > > semantics. > > A processing topology can be very simple like: > > ``` > > TopologyBuilder builder = new TopologyBuilder(); > > builder.addSource("source", "topic"); > > builder.addProcessor("processor", processorSupplier, "source"); > > new KafkaStreams(builder, streamsConfig); > > ``` > > > > My questions are: > > > > 1. Could you suggest how to achieve that? Can it be better to use > > KafkaConsumer instead of KafkaStreams? > > > > 2. From my understanding, when setting StreamsConfig `commit.interval.ms > ` > > to 0, we can turn off offset-commit by KafkaStreams internal logic (in > > StreamThread#maybeCommit), and control when to commit offsets with > > `ProcessorContext#commit`. Is my understanding right? Any expected issues > > for this approach? > > > > Thank you, > > Tomoyuki > > > > > > -- > -- Guozhang >