Hi It seems there are several ways to get to the same number in Kafka API. In Kafka Partitioner which is invoked by KafkaProducer we have this
public int partition(ProducerRecord<byte[], byte[]> record, Cluster cluster) { List<PartitionInfo> partitions = cluster.partitionsForTopic(record.topic()); int numPartitions = partitions.size(); . . . And then we have KafkaProducer.partitionsFor(topicName); It appears that the two may result in a different number causing failure during internal validation in Partitioner // they have given us a partition, use it if (record.partition() < 0 || record.partition() >= numPartitions) throw new IllegalArgumentException("Invalid partition given with record: " + record.partition() + " is not in the range [0..." + numPartitions + "].”); Basically we have RoundRobin partitioner that uses KafkaProducer.partitionsFor(topicName) to calculate the cycle, but getting the above error. Could someone please explain the difference between the two methods to get partitions size? Cheers Oleg