Kafka producer not distributing messages over partitions

Question

I am creating kafka topic as following:

kafka-topics --create --zookeeper xx.xxx.xx:2181 --replication-factor 2 --partitions 200 --topic test6 --config retention.ms=900000

and then I produce messages with golang using the following library:

    "gopkg.in/confluentinc/confluent-kafka-go.v1/kafka"

the producer configuration looks like this:

    for _, message := range bigslice {

    topic := "test6"
        p.Produce(&kafka.Message{
            TopicPartition: kafka.TopicPartition{Topic: &topic},
            Value:          []byte(message),
        }, nil)

        }

the problem that I've sent more than 200K messages but they all lands in partition 0.

what could be wrong in this situation?

Answer 1

Messages with the same key are being added to the same partition. If this is not the case, then try to include Partition: kafka.PartitionAny:

for _, message := range bigslice {

    topic := "test6"
        p.Produce(&kafka.Message{
            TopicPartition: kafka.TopicPartition{Topic: &topic, Partition: kafka.PartitionAny},
            Value: []byte(message),
        }, nil)

    }