confluent-kafka-dotnet does not produce to partitions by default the same way the Java client produces

[mtrtm]

Description

Confluent produces with the underlying librdkafka consistent_random which does not match the Java client. Since Java is the standard, can we please set to murmur2_random by default (and of course allow overrides).

How to reproduce

Publish with confluent-kafka-dotnet. Publish with Java. See the same key go to different partitions. This is the case on all versions, all OSes.

Checklist

Please provide the following information:

• [ ] A complete (i.e. we can run it), minimal program demonstrating the problem. No need to supply a project file.
• [ ] Confluent.Kafka nuget version.
• [ ] Apache Kafka version.
• [ ] Client configuration.
• [ ] Operating system.
• [ ] Provide logs (with "debug" : "..." as necessary in configuration).
• [ ] Provide broker log excerpts.
• [ ] Critical issue.

[mhowlett]

thanks for the feedback. it's a big decision to change this because many existing application using the default librdkafka partitioner (and there are lots of them) would need to explicitly update their configuration or break. we need to weigh up this inconvenience against the confusion/inconvenience caused to new users by having a different default partitioner to the java producer. which has highest impact? I'm not sure.

[noderat]

Perhaps you could start by calling it out in the README along with a code example of how to set it to use the same partitioner as Java clients?

[mhowlett]

yes, sorry our docs are currently very poor across the board for the clients. we're going to do something about this.