Overview

The figure below shows the subscription and push process.

Click to enlarge

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. The server stores only the data that is received in the last 24 hours and occupies less than 1 GB disk space. If you do not obtain data within 24 hours, the platform deletes all stacked 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 established connection.

Data Subscription

After connecting to IoTDA, an application calls an API to subscribe to data.

For details on how to configure subscriptions on the console, see AMQP Server Configuration.
For details on how to subscribe to data through APIs, see Calling APIs, Creating a Rule Trigger Condition, Creating a Rule Action, and Modifying a Rule Trigger Condition.

Format of Pushed Data

For details on the format of data pushed by the platform to applications after data subscription is created, see Data Transfer APIs.

In the HTTP message header, the value of Content-Type is application/json, and the character set is UTF-8.

TLS Support for AMQP

TLS is recommended for secure transmission between devices and the platform. Currently, TLS v1.2, v1.3, and GMTLS are supported. TLS v1.3 is recommended. GMTLS is supported only by the enterprise edition using Chinese cryptographic algorithms.

When TLS connections are used for the basic edition, standard edition, and enterprise edition that support general cryptographic algorithms, the platform supports the following cipher suites: