Does confluent-kafka-go producer PartitionAny is round robin produce message to kafka?

[hueiyuan]

Description

We found that the message on partition is not balanced. And we are not sure Partition: kafka.PartitionAny default is round robin strategy? Hope someone can assist to answer, thank you.

[milindl]

It is not round robin. It is instead sent at random (if the key is not specified). If the key is specified, then a hash of the key is taken, there are separate hash functions available available.

If the key is null or empty, it is determined using rand(3) from libc. With enough messages, it should end up being more or less uniformly distributed, hopefully.