Expected behavior when producing to non-existent partition

[alistairking]

Hey again,

We recently had a bug in some code that was doing manual assignment of partitions to messages where it was configured with an incorrect number of partitions and so was producing messages to partitions that did not exist (the topic had 100 partitions and the partitioning code was assigning messages across 1000).

Naively I would have expected the produce to fail or at worst to log an error, but from what I could tell the message was silently dropped (whether by franz or by Kafka I don't know)?

Now, obviously the solution is to use the correct number of partitions (and probably asking Kafka for this number is better than statically configuring it), but I'm curious as to whether this is the expected behavior when one does produce to a partition that does not exist.