Test against Apache Kafka #3
Description
Test against Apache Kafka can report "strange" result due to following problem ...
Consider a Kafka Producer which starts before any Kafka Consumer and it sends a bunch of messages. At a point in time Kafka Consumer starts and as configuration it has to start reading the topic not from the beginning position but from the last committed : in such situation, the Kafka Consumer can't read all messages already in the topic (sent by Kafka Producer already running) but will receive messages from now.
In the current implementation of IoT-spec we can have as result more messages sent than received.
It could be useful to have "services" (consumer) started before "devices" (producer) in order to avoid this problem with Kafka testing.