Depends on which partitioner you are using, see [1] and [2]. From what I understand the `NewHashPartitioner` comes closest to the behavior of Kafka Java producer, but instead of going round-robin for null-keyed messages it picks a partition at random.
[1] https://godoc.org/github.com/Shopify/sarama#Partitioner [2] https://github.com/Shopify/sarama/blob/master/partitioner.go On Mon, Oct 10, 2016 at 8:51 AM, Ali Akhtar <ali.rac...@gmail.com> wrote: > Hey Michael, > > We're using this one: https://github.com/Shopify/sarama > > Any ideas how that one works? > > On Mon, Oct 10, 2016 at 11:48 AM, Michael Noll <mich...@confluent.io> > wrote: > > > FYI: Kafka's new Java producer (which ships with Kafka) the behavior is > as > > follows: If no partition is explicitly specified (to send the message > to) > > AND the key is null, then the DefaultPartitioner [1] will assign messages > > to topic partitions in a round-robin fashion. See the javadoc and also > the > > little bit of code in [1] for details. > > > > Not sure which Go client you're using exactly so I can't tell whether > your > > Go client follows the behavior of Kafka's Java producer. > > > > -Michael > > > > > > > > > > [1] > > https://github.com/apache/kafka/blob/trunk/clients/src/ > > main/java/org/apache/kafka/clients/producer/internals/ > > DefaultPartitioner.java > > > > > > On Mon, Oct 10, 2016 at 7:53 AM, Ali Akhtar <ali.rac...@gmail.com> > wrote: > > > > > If keys are null, what happens in terms of partitioning, is the load > > spread > > > evenly..? > > > > > > On Mon, Oct 10, 2016 at 7:59 AM, Gwen Shapira <g...@confluent.io> > wrote: > > > > > > > Kafka itself supports null keys. I'm not sure about the Go client you > > > > use, but Confluent's Go client also supports null keys > > > > (https://github.com/confluentinc/confluent-kafka-go/). > > > > > > > > If you decide to generate keys and you want even spread, a random > > > > number generator is probably your best bet. > > > > > > > > Gwen > > > > > > > > On Sun, Oct 9, 2016 at 6:05 PM, Ali Akhtar <ali.rac...@gmail.com> > > wrote: > > > > > A kafka producer written elsewhere that I'm using, which uses the > Go > > > > kafka > > > > > driver, is sending messages where the key is null. > > > > > > > > > > Is this OK - or will this cause issues due to partitioning not > > > happening > > > > > correctly? > > > > > > > > > > What would be a good way to generate keys in this case, to ensure > > even > > > > > partition spread? > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > -- > > > > Gwen Shapira > > > > Product Manager | Confluent > > > > 650.450.2760 | @gwenshap > > > > Follow us: Twitter | blog > > > > > > > > > >
