The delivery report callback will be called once for each message
accepted by Producer::produce() (et.al) with
Message::err() set to indicate the result of the produce request.
The callback is called when a message is succesfully produced or
if librdkafka encountered a permanent failure, or the retry counter for
temporary errors has been exhausted.
An application must call poll() at regular intervals to
serve queued delivery report callbacks.
Delivery Report callback class
The delivery report callback will be called once for each message accepted by Producer::produce() (et.al) with Message::err() set to indicate the result of the produce request.
The callback is called when a message is succesfully produced or if librdkafka encountered a permanent failure, or the retry counter for temporary errors has been exhausted.
An application must call poll() at regular intervals to serve queued delivery report callbacks.