Message key is missing on the broker side

[bsdgox]

Hi everyone,

We have the following scenario: Two different producers are writing into the one topic on the broker. One of the producers uses librdkafa and sending messages seems to work, but although we set the key and we don't set the partition, we can see the message we get on the broker side contains body, but the key is missing.

So, the question is: Is there any scenario you can think of how come that we get the message body correctly, but the key is missing?

Additional information: If we send the very same message (with the same key) into a different test topic, we get complete message on the broker side (i.e. key is properly set, and visible).

Thank you in advance!