offset
https://cloud.tencent.com/developer/article/1451224
RocketMq combat -offset
First, let's define what Offset meaning, RocketMQ, one type of message into a Topic in order to be able parallel, there will be more generally a Topic Message Queue (also can be set to a), Offset refers to a Topic a message at a certain position in the message Queue , may be positioned by the value of Offset to this message, or a message indicating the start backward from this Consumer continue processing.
group
Producer There is a need to set the value of ProducerGroup as Producer is distributed deployment, we need to belong together logically associate producer, then by ProducerGroup this value set, belong to a group of messages generated by producer theory It should be on a business type. Producer construction time can be specified:
private final DefaultMQProducer PRODUCER = new DefaultMQProducer("Producer-Group1");
