the number of messages batched at the producer
the serializer class for keys (defaults to the same as for values)
the maximum size of the blocking queue for buffering on the producer
Timeout for event enqueue: 0: events will be enqueued immediately or dropped if the queue is full -ve: enqueue will block indefinitely if the queue is full +ve: enqueue will block up to this many milliseconds if the queue is full
the serializer class for values