Overview

Subscription: AMQP is short for Advanced Message Queuing Protocol. You can create a subscription task on the IoTDA console. You can call platform APIs Creating a Rule Trigger Condition, Creating a Rule Action, and Modifying a Rule Trigger Condition to configure and activate rules for obtaining changed device service details and management details. (Service details include device lifecycle management, device data reporting, device message status, and device status. Management details include software/firmware upgrade status and result.) The AMQP message channel must be specified during subscription creation.

Push: After a subscription is created, the platform pushes the corresponding change to the specified AMQP message queue based on the type of data subscribed. If an application does not subscribe to a specific type of data notification, the platform does not push the data to the application even if the data has changed. You can use the AMQP client to establish a connection with the platform to receive data. The figure below shows the subscription and push process.

Push mechanism: After receiving a message from the platform, the application returns a response. (The automatic response mode is recommended.) If the application does not pull data after the connection is established, data will be stacked on the server. When the maximum cache duration (one day) is reached, the platform clears the data. If the application does not respond in time after receiving the message and the persistent connection is interrupted, the corresponding data will be pushed again in the next connection established.