Before this fix, PublishKafka (0.9) and PublishKafka_0_10 fail with empty incoming FlowFiles due to 'transfer relationship not specified' error.
Because the internal 'publish' method is not called as StreamDemarcator does not emit any token regardless whether demarcator is set or not.
As for PublishKafka_0_11 and PublishKafka_1_0, empty FlowFiles are transferred to 'success' relationship, however no Kafka message is sent to Kafka.
Since Kafka allows 0 byte body empty messages, NiFi should be able to send it, too.
This commit changes above current situation to the followings, with all PublishKafka_* processors:
- If demarcator is not set, then publish incoming FlowFile content as it is. This enables sending an empty Kafka message.
- If demarcator is set, send each token as a separate message.
Even if no token is found (empty incoming FlowFile), transfer the FlowFile to 'success'.
This closes#2362.
Signed-off-by: Mark Payne <markap14@hotmail.com>
It is possible null values to be stored in Kafka topics. Fixed handle this scenario.
Notice without this fix, the consumer is unable to consume more messages (at least
without removing messages from the queue).
Koji Kawamura
jknulst
Mark Payne
matthew-silverman
joewitt
Janosch Woschitz
Jeff Storck
gardellajuanpablo