You can configure data inbound rules of Message Queue for MQTT to import data from other Alibaba Cloud services to Message Queue for MQTT. This topic describes the working mechanism, scenarios, and limits of importing data from other Alibaba Cloud services to Message Queue for MQTT. This topic also describes the resource mappings between Message Queue for MQTT and other Alibaba Cloud services.

Working mechanism

You must create data inbound rules before you can import data from other Alibaba Cloud services to Message Queue for MQTT. Message Queue for MQTT uses data inbound rules to obtain data from other Alibaba Cloud services. Then, the Message Queue for MQTT broker pushes the data to Message Queue for MQTT clients by using the Message Queuing Telemetry Transport (MQTT) protocol. You can call the APIs of the Alibaba Cloud services to send data to the Message Queue for MQTT clients. Inbound data

Scenarios

Message sending

A backend service application deployed on the cloud sends a message to Message Queue for Apache RocketMQ. Based on the configured data inbound rule, Message Queue for MQTT maps the topics of Message Queue for Apache RocketMQ to topics of Message Queue for MQTT, and pushes the corresponding data to the destination Message Queue for MQTT clients.

Precautions

When Message Queue for MQTT uses a data inbound rule to receive messages from Message Queue for Apache RocketMQ, the Message Queue for MQTT client may receive messages with latency if the Message Queue for Apache RocketMQ server is being updated. For more information about service updates, see Notice List.

Limits

  • You can import data only from Message Queue for Apache RocketMQ to Message Queue for MQTT.

Resource mapping methods

Message Queue for MQTT supports multi-level topics, whereas Message Queue for Apache RocketMQ supports single-level topics. Therefore, when a data inbound rule is used to map resources, a level-1 topic in Message Queue for MQTT is mapped to a topic in Message Queue for Apache RocketMQ, and data in the Message Queue for Apache RocketMQ topic is exported to the level-1 topic in Message Queue for MQTT. Level-2 and level-3 topics in Message Queue for MQTT are mapped to the message properties in Message Queue for Apache RocketMQ.

Table 1. Mappings
Message Queue for MQTT resource Alibaba Cloud service Resource of the Alibaba Cloud service Property mappings
Topics of Message Queue for MQTT Message Queue for Apache RocketMQ Topics of Message Queue for Apache RocketMQ Message structure mappings between Message Queue for MQTT and Message Queue for Apache RocketMQ

References

For more information about console operations, see Manage data inbound rules.