Does Samza's OutgoingMessageEnvelope require a SerDe for partitionKey and how do I specify it?

Question

Similar to how-can-you-create-a-partition-on-a-kafka-topic-using-samza I need to construct a message controlling how it's routed via use of partitionKey. key and message do require a SerDe but I'm not sure if partitionKey does as well. If so what is the configuration syntax? I suppose I can rely on Samza internally using key as the partitionKey but I'd rather keep them explicit and separate.

Answer 1

From the source code it doesn't seem like partition key requires a SerDe - note key and message have a corresponding xxxxSerializerName

public class OutgoingMessageEnvelope {
  private final SystemStream systemStream;
  private final String keySerializerName;
  private final String messageSerializerName;
  private final Object partitionKey;
  private final Object key;
  private final Object message;