Messaging Sources are sources that require an open connection to stream data from the source to the consumer.
Messaging Consumer
Messaging consumers are the ones responsible for connecting to remote messaging system,
keep listening for new data, and consume data when available.
The consumers are created when the request to start “listening” to remote topic is submitted
at runtime. The underlying Kafka / RabbitMQ client consumers are created in the constructor of
messaging consumer implementation - KafkaMessageConsumer, RabbitMqMessageConsumer.
The remote topics are polled for records when the consumer thread begins, i.e. inside
the Java Callable’s call method.