This topic answers common questions about calling ApsaraMQ for MQTT API operations.
Why do I receive an "API not support" error when I create a rule?
The instance version is too old and does not support the rule creation feature. Purchase a new instance and create the rule again.
Why do messages sent over the HTTP interface not have a message trace?
The message trace feature is not supported for messages sent over the HTTP interface. To view message traces, send messages using an MQTT software development kit (SDK). For more information, see Send a single message to ApsaraMQ for MQTT.
Intermittent timeout errors occur when you call the API.
ApsaraMQ for MQTT limits the frequency of API calls, measured in queries per second (QPS). If you exceed the QPS limit, rate limiting is triggered. For more information about the specific limits, see QPS limits.
Why is the SignatureDoesNotMatch error returned after I call API operations using the SDK mode?
The authentication failed. Check whether your AccessKey ID and AccessKey secret are correctly specified. For information about how to obtain the AccessKey ID and AccessKey secret, see Create an AccessKey pair.