This topic describes instance types and billing methods of Message Queue for MQTT. You can select an instance type and a billing method based on your business requirements.
- Message Queue for MQTT V3.x.x and later no longer use Message Queue for Apache RocketMQ for storage. A maximum of 25 topics can be created in a single Message Queue for MQTT instance. If you want to create more topics, submit a ticket. You will be charged for the resources that exceed this limit.
- If you use Message Queue for MQTT V3.x.x to exchange data with other Alibaba Cloud services based on specified rules, you will be charged for these services based on their own billing methods. Message Queue for MQTT can interact only with Message Queue for Apache RocketMQ, for which you will be charged for topic resource usage and API calls. For more information, see Message Queue for Apache RocketMQBilling overview.
- Message Queue for MQTT V2.x.x uses Message Queue for Apache RocketMQ for storage. When you use Message Queue for MQTT, you are also charged for topic resource usage and API calls for Message Queue for Apache RocketMQ. Therefore, billing details about Message Queue for Apache RocketMQ are listed in the Product Cost Summary section.
Instance types and billing methods
When you transmit messages by using the Message Queuing Telemetry Transport (MQTT) protocol, the settings of the QoS and cleanSession parameters affect the actual charges. You are charged for messages, including calls of the client API and the cloud API. In billing, the number of messages that correspond to a transmission quality level in the specified protocol is multiplied by the calculation ratio that corresponds to this level. For example, if the number of messages that correspond to a transmission quality level is 1, 1 is multiplied by the corresponding calculation ratio.
The following table describes the calculation ratios in Message Queue for MQTT, which correspond to different transmission quality levels.
|Transmission quality level||Calculation ratio|
QoSparameter is set to 2 and the
cleanSessionparameter is set to false. However, if you set this transmission quality level, the calculation ratio is 5.
For more information about the QoS and cleanSession parameters, see Terms.